{-# LANGUAGE ConstraintKinds     #-}
{-# LANGUAGE CPP                 #-}
{-# LANGUAGE FlexibleContexts    #-}
{-# LANGUAGE MultiWayIf          #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications    #-}
{-# LANGUAGE TypeFamilies        #-}
{-# LANGUAGE ViewPatterns        #-}

{-# OPTIONS_GHC -Wno-incomplete-record-updates #-}
{-# OPTIONS_GHC -Wno-incomplete-uni-patterns   #-}

{-
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998

Renaming of expressions

Basically dependency analysis.

Handles @Match@, @GRHSs@, @HsExpr@, and @Qualifier@ datatypes.  In
general, all of these functions return a renamed thing, and a set of
free variables.
-}

module GHC.Rename.Expr (
        rnLExpr, rnExpr, rnStmts,
        AnnoBody, UnexpectedStatement(..)
   ) where

import GHC.Prelude
import GHC.Data.FastString

import GHC.Rename.Bind ( rnLocalBindsAndThen, rnLocalValBindsLHS, rnLocalValBindsRHS
                        , rnMatchGroup, rnGRHS, makeMiniFixityEnv)
import GHC.Hs
import GHC.Tc.Errors.Types
import GHC.Tc.Utils.Env ( isBrackStage )
import GHC.Tc.Utils.Monad
import GHC.Unit.Module ( getModule, isInteractiveModule )
import GHC.Rename.Env
import GHC.Rename.Fixity
import GHC.Rename.Utils ( bindLocalNamesFV, checkDupNames
                        , bindLocalNames
                        , mapMaybeFvRn, mapFvRn
                        , warnUnusedLocalBinds, typeAppErr
                        , checkUnusedRecordWildcard
                        , wrapGenSpan, genHsIntegralLit, genHsTyLit
                        , genHsVar, genLHsVar, genHsApp, genHsApps, genHsApps'
                        , genAppType, isIrrefutableHsPat )
import GHC.Rename.Unbound ( reportUnboundName )
import GHC.Rename.Splice  ( rnTypedBracket, rnUntypedBracket, rnTypedSplice, rnUntypedSpliceExpr, checkThLocalName )
import GHC.Rename.HsType
import GHC.Rename.Pat
import GHC.Driver.DynFlags
import GHC.Builtin.Names
import GHC.Builtin.Types ( nilDataConName )

import GHC.Types.Basic (TypeOrKind (TypeLevel))
import GHC.Types.FieldLabel
import GHC.Types.Fixity
import GHC.Types.Id.Make
import GHC.Types.Name
import GHC.Types.Name.Set
import GHC.Types.Name.Reader
import GHC.Types.Unique.Set
import GHC.Types.SourceText
import GHC.Types.SrcLoc
import GHC.Utils.Misc
import GHC.Data.List.SetOps ( removeDupsOn )
import GHC.Data.Maybe
import GHC.Utils.Error
import GHC.Utils.Panic
import GHC.Utils.Outputable as Outputable

import qualified GHC.LanguageExtensions as LangExt

import Language.Haskell.Syntax.Basic (FieldLabelString(..))

import Control.Monad
import Data.List (unzip4, minimumBy)
import Data.List.NonEmpty ( NonEmpty(..), nonEmpty )
import Control.Arrow (first)
import Data.Ord
import Data.Array
import qualified Data.List.NonEmpty as NE

{- Note [Handling overloaded and rebindable constructs]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Nomenclature
-------------
* Expansion (`HsExpr GhcRn -> HsExpr GhcRn`): expand between renaming and
  typechecking, using the `XXExprGhcRn` constructor of `HsExpr`.
* Desugaring (`HsExpr GhcTc -> Core.Expr`): convert the typechecked `HsSyn` to Core.  This is done in GHC.HsToCore


For overloaded constructs (overloaded literals, lists, strings), and
rebindable constructs (e.g. if-then-else), our general plan is this,
using overloaded labels #foo as an example:

* In the RENAMER: transform
      HsOverLabel "foo"
      ==> XExpr (ExpandedThingRn (HsOverLabel #foo)
                                 (fromLabel `HsAppType` "foo"))
  We write this more compactly in concrete-syntax form like this
      #foo  ==>  fromLabel @"foo"

  Recall that in (ExpandedThingRn orig expanded), 'orig' is the original term
  the user wrote, and 'expanded' is the expanded or desugared version
  to be typechecked.

* In the TYPECHECKER: typecheck the expansion, in this case
      fromLabel @"foo"
  The typechecker (and desugarer) will never see HsOverLabel

In effect, the renamer does a bit of desugaring. Recall GHC.Hs.Expr
Note [Rebindable syntax and XXExprGhcRn], which describes the use of XXExprGhcRn.

RebindableSyntax:
  If RebindableSyntax is off we use the built-in 'fromLabel', defined in
     GHC.Builtin.Names.fromLabelClassOpName
  If RebindableSyntax if ON, we look up "fromLabel" in the environment
     to get whichever one is in scope.
This is accomplished by lookupSyntaxName, and it applies to all the
constructs below.

See also Note [Handling overloaded and rebindable patterns] in GHC.Rename.Pat
for the story with patterns.

Here are the expressions that we transform in this way. Some are uniform,
but several have a little bit of special treatment:

* HsIf (if-the-else)
     if b then e1 else e2  ==>  ifThenElse b e1 e2
  We do this /only/ if rebindable syntax is on, because the coverage
  checker looks for HsIf (see GHC.HsToCore.Ticks.addTickHsExpr)
  That means the typechecker and desugarer need to understand HsIf
  for the non-rebindable-syntax case.

* OverLabel (overloaded labels, #lbl)
     #lbl  ==>  fromLabel @"lbl"
  As ever, we use lookupSyntaxName to look up 'fromLabel'
  See Note [Overloaded labels] below

* ExplicitList (explicit lists [a,b,c])
  When (and only when) OverloadedLists is on
     [e1,e2]  ==>  fromListN 2 [e1,e2]
  NB: the type checker and desugarer still see ExplicitList,
      but to them it always means the built-in lists.

* SectionL and SectionR (left and right sections)
     (`op` e) ==> rightSection op e
     (e `op`) ==> leftSection  (op e)
  where `leftSection` and `rightSection` are representation-polymorphic
  wired-in Ids. See Note [Left and right sections]

* To understand why expansions for `OpApp` is done in `GHC.Tc.Gen.Head.splitHsApps`
  see Note [Doing XXExprGhcRn in the Renamer vs Typechecker] below.

* RecordUpd: we desugar record updates into case expressions,
  in GHC.Tc.Gen.Expr.tcExpr.

  Example:

    data T p q = T1 { x :: Int, y :: Bool, z :: Char }
               | T2 { v :: Char }
               | T3 { x :: Int }
               | T4 { p :: Float, y :: Bool, x :: Int }
               | T5

    e { x=e1, y=e2 }
      ===>
    let { x' = e1; y' = e2 } in
    case e of
       T1 _ _ z -> T1 x' y' z
       T4 p _ _ -> T4 p y' x'

  See Note [Record Updates] in GHC.Tc.Gen.Expr for more details.

  To understand Why is this done in the typechecker, and not in the renamer
  see Note [Doing XXExprGhcRn in the Renamer vs Typechecker]

* HsDo: We expand `HsDo` statements in `Ghc.Tc.Gen.Do`.

    - For example, a user written code:

                  do { x <- e1 ; g x ; return (f x) }

      is expanded to:

                   (>>=) e1
                         (\x -> ((>>) (g x)
                                      (return (f x))))

     See Note [Expanding HsDo with XXExprGhcRn] in `Ghc.Tc.Gen.Do` for more details.
     To understand why is this done in the typechecker and not in the renamer.
     See Note [Doing XXExprGhcRn in the Renamer vs Typechecker]

Note [Overloaded labels]
~~~~~~~~~~~~~~~~~~~~~~~~
For overloaded labels, note that we /only/ apply `fromLabel` to the
Symbol argument, so the resulting expression has type
    fromLabel @"foo" :: forall a. IsLabel "foo" a => a
Now ordinary Visible Type Application can be used to instantiate the 'a':
the user may have written (#foo @Int).

Notice that this all works fine in a kind-polymorphic setting (#19154).
Suppose we have
    fromLabel :: forall {k1} {k2} (a:k1). blah

Then we want to instantiate those inferred quantifiers k1,k2, before
type-applying to "foo", so we get
    fromLabel @Symbol @blah @"foo" ...

And those inferred kind quantifiers will indeed be instantiated when we
typecheck the renamed-syntax call (fromLabel @"foo").

Note [Doing XXExprGhcRn in the Renamer vs Typechecker]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We expand some `HsExpr GhcRn` code at various places, usually, on the fly,
depending on when it is more convenient. It may be beneficial to have a
separate `HsExpr GhcRn -> HsExpr GhcRn` pass that does this expansion uniformly
in the future when we have enough cases to cater for. For the time being,
this note documents which language feature is expanded at which phase,
and the reasons for doing so.

  ** `HsIf` Expansions
  --------------------
  `HsIf` expansions are expanded in the Renamer becuase it is more convinent
  to do so there and then not worry about it in the later stage.
  `-XRebindableSyntax` is used to decide whether we use the `HsIf` or user defined if


  ** `OpApp` Expansions
  ---------------------
  The typechecker turns `OpApp` into a use of `XXExprGhcRn`
  on the fly, in `GHC.Tc.Gen.Head.splitHsApps`.
  The language extension `RebindableSyntax` does not affect this behaviour.

  It's a bit painful to transform `OpApp e1 op e2` to a `XXExprGhcRn`
  form, because the renamer does precedence rearrangement after name
  resolution. So the renamer leaves an `OpApp` as an `OpApp`.

  ** Record Update Syntax `RecordUpd` Expansions
  ----------------------------------------------
  This is done in the typechecker on the fly (`GHC.Tc.Expr.tcExpr`), and not the renamer, for two reasons:

    - (Until we implement GHC proposal #366)
      We need to know the type of the record to disambiguate its fields.

    - We use the type signature of the data constructor to provide `IdSigs`
      to the let-bound variables (x', y' in the example of
      Note [Handling overloaded and rebindable constructs] above).
      This is needed to accept programs such as

          data R b = MkR { f :: (forall a. a -> a) -> (Int,b), c :: Int }
          foo r = r { f = \ k -> (k 3, k 'x') }

      in which an updated field has a higher-rank type.
      See Wrinkle [Using IdSig] in Note [Record Updates] in GHC.Tc.Gen.Expr.

  ** `HsDo` Statement Expansions
  -----------------------------------
  The expansion for do block statements is done on the fly right before typechecking in `GHC.Tc.Gen.Expr`
  using `GHC.Tc.Gen.Do.expandDoStmts`. There are 2 main reasons:

  -  During the renaming phase, we may not have all the constructor details `HsConDetails` populated in the
     data structure. This would result in an inaccurate irrefutability analysis causing
     the continuation lambda body to be wrapped with `fail` alternatives when not needed.
     See Part 1. of Note [Expanding HsDo with XXExprGhcRn] (test pattern-fails.hs)

  -  If the expansion is done on the fly during renaming, expressions that
     have explicit type applications using (-XTypeApplciations) will not work (cf. Let statements expansion)
     as the name freshening happens from the root of the AST to the leaves,
     but the expansion happens in the opposite direction (from leaves to the root),
     causing the renamer to miss the scoped type variables.
-}

{-
************************************************************************
*                                                                      *
\subsubsection{Expressions}
*                                                                      *
************************************************************************
-}

rnExprs :: [LHsExpr GhcPs] -> RnM ([LHsExpr GhcRn], FreeVars)
rnExprs :: [LHsExpr GhcPs] -> RnM ([XRec GhcRn (HsExpr GhcRn)], FreeVars)
rnExprs [LHsExpr GhcPs]
ls = [GenLocated SrcSpanAnnA (HsExpr GhcPs)]
-> FreeVars
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated SrcSpanAnnA (HsExpr GhcRn)], FreeVars)
rnExprs' [LHsExpr GhcPs]
[GenLocated SrcSpanAnnA (HsExpr GhcPs)]
ls FreeVars
forall a. UniqSet a
emptyUniqSet
 where
  rnExprs' :: [GenLocated SrcSpanAnnA (HsExpr GhcPs)]
-> FreeVars
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated SrcSpanAnnA (HsExpr GhcRn)], FreeVars)
rnExprs' [] FreeVars
acc = ([GenLocated SrcSpanAnnA (HsExpr GhcRn)], FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated SrcSpanAnnA (HsExpr GhcRn)], FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ([], FreeVars
acc)
  rnExprs' (GenLocated SrcSpanAnnA (HsExpr GhcPs)
expr:[GenLocated SrcSpanAnnA (HsExpr GhcPs)]
exprs) FreeVars
acc =
   do { (expr', fvExpr) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
GenLocated SrcSpanAnnA (HsExpr GhcPs)
expr
        -- Now we do a "seq" on the free vars because typically it's small
        -- or empty, especially in very long lists of constants
      ; let  acc' = FreeVars
acc FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvExpr
      ; (exprs', fvExprs) <- acc' `seq` rnExprs' exprs acc'
      ; return (expr':exprs', fvExprs) }

-- Variables. We look up the variable and return the resulting name.

rnLExpr :: LHsExpr GhcPs -> RnM (LHsExpr GhcRn, FreeVars)
rnLExpr :: LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr = (HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars))
-> GenLocated SrcSpanAnnA (HsExpr GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnExpr

rnExpr :: HsExpr GhcPs -> RnM (HsExpr GhcRn, FreeVars)

finishHsVar :: LocatedA Name -> RnM (HsExpr GhcRn, FreeVars)
-- Separated from rnExpr because it's also used
-- when renaming infix expressions
finishHsVar :: LocatedA Name -> TcM (HsExpr GhcRn, FreeVars)
finishHsVar (L SrcSpanAnnA
l Name
name)
 = do { this_mod <- IOEnv (Env TcGblEnv TcLclEnv) Module
forall (m :: * -> *). HasModule m => m Module
getModule
      ; when (nameIsLocalOrFrom this_mod name) $
        checkThLocalName name
      ; return (HsVar noExtField (L (l2l l) name), unitFV name) }

rnUnboundVar :: RdrName -> RnM (HsExpr GhcRn, FreeVars)
rnUnboundVar :: RdrName -> TcM (HsExpr GhcRn, FreeVars)
rnUnboundVar RdrName
v = do
  deferOutofScopeVariables <- GeneralFlag -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. GeneralFlag -> TcRnIf gbl lcl Bool
goptM GeneralFlag
Opt_DeferOutOfScopeVariables
  -- See Note [Reporting unbound names] for difference between qualified and unqualified names.
  unless (isUnqual v || deferOutofScopeVariables) (reportUnboundName v >> return ())
  return (HsUnboundVar noExtField v, emptyFVs)

rnExpr :: HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnExpr (HsVar XVar GhcPs
_ (L SrcSpanAnnN
l RdrName
v))
  = do { dflags <- IOEnv (Env TcGblEnv TcLclEnv) DynFlags
forall (m :: * -> *). HasDynFlags m => m DynFlags
getDynFlags
       ; mb_gre <- lookupExprOccRn v
       ; case mb_gre of {
           Maybe GlobalRdrElt
Nothing -> RdrName -> TcM (HsExpr GhcRn, FreeVars)
rnUnboundVar RdrName
v ;
           Just GlobalRdrElt
gre ->
    do { let nm :: Name
nm   = GlobalRdrElt -> Name
forall info. GlobalRdrEltX info -> Name
greName GlobalRdrElt
gre
             info :: GREInfo
info = GlobalRdrElt -> GREInfo
greInfo GlobalRdrElt
gre
       ; if | IAmRecField RecFieldInfo
fld_info <- GREInfo
info
            -- Since GHC 9.4, such occurrences of record fields must be
            -- unambiguous. For ambiguous occurrences, we arbitrarily pick one
            -- matching GRE and add a name clash error
            -- (see lookupGlobalOccRn_overloaded, called by lookupExprOccRn).
            -> do { let sel_name :: Name
sel_name = FieldLabel -> Name
flSelector (FieldLabel -> Name) -> FieldLabel -> Name
forall a b. (a -> b) -> a -> b
$ RecFieldInfo -> FieldLabel
recFieldLabel RecFieldInfo
fld_info
                  ; this_mod <- IOEnv (Env TcGblEnv TcLclEnv) Module
forall (m :: * -> *). HasModule m => m Module
getModule
                  ; when (nameIsLocalOrFrom this_mod sel_name) $
                      checkThLocalName sel_name
                  ; return (HsRecSel noExtField (FieldOcc sel_name (L l v) ), unitFV sel_name)
                  }
            | Name
nm Name -> Name -> Bool
forall a. Eq a => a -> a -> Bool
== Name
nilDataConName
              -- Treat [] as an ExplicitList, so that
              -- OverloadedLists works correctly
              -- Note [Empty lists] in GHC.Hs.Expr
            , Extension -> DynFlags -> Bool
xopt Extension
LangExt.OverloadedLists DynFlags
dflags
            -> HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnExpr (XExplicitList GhcPs -> [LHsExpr GhcPs] -> HsExpr GhcPs
forall p. XExplicitList p -> [LHsExpr p] -> HsExpr p
ExplicitList XExplicitList GhcPs
AnnList
forall a. NoAnn a => a
noAnn [])

            | Bool
otherwise
            -> LocatedA Name -> TcM (HsExpr GhcRn, FreeVars)
finishHsVar (SrcSpanAnnA -> Name -> LocatedA Name
forall l e. l -> e -> GenLocated l e
L (SrcSpanAnnN -> SrcSpanAnnA
forall a b. (HasLoc a, HasAnnotation b) => a -> b
l2l SrcSpanAnnN
l) Name
nm)
        }}}

rnExpr (HsIPVar XIPVar GhcPs
x HsIPName
v)
  = (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XIPVar GhcRn -> HsIPName -> HsExpr GhcRn
forall p. XIPVar p -> HsIPName -> HsExpr p
HsIPVar XIPVar GhcPs
XIPVar GhcRn
x HsIPName
v, FreeVars
emptyFVs)

rnExpr (HsUnboundVar XUnboundVar GhcPs
_ RdrName
v)
  = (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XUnboundVar GhcRn -> RdrName -> HsExpr GhcRn
forall p. XUnboundVar p -> RdrName -> HsExpr p
HsUnboundVar XUnboundVar GhcRn
NoExtField
noExtField RdrName
v, FreeVars
emptyFVs)

-- HsOverLabel: see Note [Handling overloaded and rebindable constructs]
rnExpr (HsOverLabel XOverLabel GhcPs
_ SourceText
src FastString
v)
  = do { (from_label, fvs) <- Name -> RnM (Name, FreeVars)
lookupSyntaxName Name
fromLabelClassOpName
       ; return ( mkExpandedExpr (HsOverLabel noExtField src v) $
                  HsAppType noExtField (genLHsVar from_label) hs_ty_arg
                , fvs ) }
  where
    hs_ty_arg :: HsWildCardBndrs GhcRn (LocatedAn AnnListItem (HsType GhcRn))
hs_ty_arg = LocatedAn AnnListItem (HsType GhcRn)
-> HsWildCardBndrs GhcRn (LocatedAn AnnListItem (HsType GhcRn))
forall thing. thing -> HsWildCardBndrs GhcRn thing
mkEmptyWildCardBndrs (LocatedAn AnnListItem (HsType GhcRn)
 -> HsWildCardBndrs GhcRn (LocatedAn AnnListItem (HsType GhcRn)))
-> LocatedAn AnnListItem (HsType GhcRn)
-> HsWildCardBndrs GhcRn (LocatedAn AnnListItem (HsType GhcRn))
forall a b. (a -> b) -> a -> b
$ HsType GhcRn -> LocatedAn AnnListItem (HsType GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan (HsType GhcRn -> LocatedAn AnnListItem (HsType GhcRn))
-> HsType GhcRn -> LocatedAn AnnListItem (HsType GhcRn)
forall a b. (a -> b) -> a -> b
$
                XTyLit GhcRn -> HsTyLit GhcRn -> HsType GhcRn
forall pass. XTyLit pass -> HsTyLit pass -> HsType pass
HsTyLit XTyLit GhcRn
NoExtField
noExtField (XStrTy GhcRn -> FastString -> HsTyLit GhcRn
forall pass. XStrTy pass -> FastString -> HsTyLit pass
HsStrTy XStrTy GhcRn
SourceText
NoSourceText FastString
v)

rnExpr (HsLit XLitE GhcPs
x lit :: HsLit GhcPs
lit@(HsString XHsString GhcPs
src FastString
s))
  = do { opt_OverloadedStrings <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.OverloadedStrings
       ; if opt_OverloadedStrings then
            rnExpr (HsOverLit x (mkHsIsString src s))
         else do {
            ; rnLit lit
            ; return (HsLit x (convertLit lit), emptyFVs) } }

rnExpr (HsLit XLitE GhcPs
x HsLit GhcPs
lit)
  = do { HsLit GhcPs -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall p. HsLit p -> IOEnv (Env TcGblEnv TcLclEnv) ()
rnLit HsLit GhcPs
lit
       ; (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XLitE GhcRn -> HsLit GhcRn -> HsExpr GhcRn
forall p. XLitE p -> HsLit p -> HsExpr p
HsLit XLitE GhcPs
XLitE GhcRn
x(HsLit GhcPs -> HsLit GhcRn
forall (p1 :: Pass) (p2 :: Pass).
HsLit (GhcPass p1) -> HsLit (GhcPass p2)
convertLit HsLit GhcPs
lit), FreeVars
emptyFVs) }

rnExpr (HsOverLit XOverLitE GhcPs
x HsOverLit GhcPs
lit)
  = do { ((lit', mb_neg), fvs) <- HsOverLit GhcPs
-> RnM ((HsOverLit GhcRn, Maybe (HsExpr GhcRn)), FreeVars)
forall t.
(XXOverLit t ~ DataConCantHappen) =>
HsOverLit t
-> RnM ((HsOverLit GhcRn, Maybe (HsExpr GhcRn)), FreeVars)
rnOverLit HsOverLit GhcPs
lit -- See Note [Negative zero]
       ; case mb_neg of
              Maybe (HsExpr GhcRn)
Nothing -> (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XOverLitE GhcRn -> HsOverLit GhcRn -> HsExpr GhcRn
forall p. XOverLitE p -> HsOverLit p -> HsExpr p
HsOverLit XOverLitE GhcPs
XOverLitE GhcRn
x HsOverLit GhcRn
lit', FreeVars
fvs)
              Just HsExpr GhcRn
neg ->
                 (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XApp GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XApp p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsApp XApp GhcRn
NoExtField
noExtField (HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall e a. HasAnnotation e => a -> GenLocated e a
noLocA HsExpr GhcRn
neg) (HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall e a. HasAnnotation e => a -> GenLocated e a
noLocA (XOverLitE GhcRn -> HsOverLit GhcRn -> HsExpr GhcRn
forall p. XOverLitE p -> HsOverLit p -> HsExpr p
HsOverLit XOverLitE GhcPs
XOverLitE GhcRn
x HsOverLit GhcRn
lit'))
                        , FreeVars
fvs ) }

rnExpr (HsApp XApp GhcPs
x LHsExpr GhcPs
fun LHsExpr GhcPs
arg)
  = do { (fun',fvFun) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
fun
       ; (arg',fvArg) <- rnLExpr arg
       ; return (HsApp x fun' arg', fvFun `plusFV` fvArg) }

rnExpr (HsAppType XAppTypeE GhcPs
_ LHsExpr GhcPs
fun LHsWcType (NoGhcTc GhcPs)
arg)
  = do { type_app <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.TypeApplications
       ; unless type_app $ addErr $ typeAppErr TypeLevel $ hswc_body arg
       ; (fun',fvFun) <- rnLExpr fun
       ; (arg',fvArg) <- rnHsWcType HsTypeCtx arg
       ; return (HsAppType noExtField fun' arg', fvFun `plusFV` fvArg) }

rnExpr (OpApp XOpApp GhcPs
_ LHsExpr GhcPs
e1 LHsExpr GhcPs
op LHsExpr GhcPs
e2)
  = do  { (e1', fv_e1) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
e1
        ; (e2', fv_e2) <- rnLExpr e2
        ; (op', fv_op) <- rnLExpr op

        -- Deal with fixity
        -- When renaming code synthesised from "deriving" declarations
        -- we used to avoid fixity stuff, but we can't easily tell any
        -- more, so I've removed the test.  Adding HsPars in GHC.Tc.Deriv.Generate
        -- should prevent bad things happening.
        ; fixity <- case op' of
              L SrcSpanAnnA
_ (HsVar XVar GhcRn
_ (L SrcSpanAnnN
_ Name
n)) -> Name -> IOEnv (Env TcGblEnv TcLclEnv) Fixity
lookupFixityRn Name
n
              L SrcSpanAnnA
_ (HsRecSel XRecSel GhcRn
_ FieldOcc GhcRn
f)    -> FieldOcc GhcRn -> IOEnv (Env TcGblEnv TcLclEnv) Fixity
lookupFieldFixityRn FieldOcc GhcRn
f
              GenLocated SrcSpanAnnA (HsExpr GhcRn)
_ -> Fixity -> IOEnv (Env TcGblEnv TcLclEnv) Fixity
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (SourceText -> Int -> FixityDirection -> Fixity
Fixity SourceText
NoSourceText Int
minPrecedence FixityDirection
InfixL)
                   -- c.f. lookupFixity for unbound

        ; lexical_negation <- xoptM LangExt.LexicalNegation
        ; let negation_handling | Bool
lexical_negation = NegationHandling
KeepNegationIntact
                                | Bool
otherwise = NegationHandling
ReassociateNegation
        ; final_e <- mkOpAppRn negation_handling e1' op' fixity e2'
        ; return (final_e, fv_e1 `plusFV` fv_op `plusFV` fv_e2) }

rnExpr (NegApp XNegApp GhcPs
_ LHsExpr GhcPs
e SyntaxExpr GhcPs
_)
  = do { (e', fv_e)         <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
e
       ; (neg_name, fv_neg) <- lookupSyntax negateName
       ; final_e            <- mkNegAppRn e' neg_name
       ; return (final_e, fv_e `plusFV` fv_neg) }

------------------------------------------
-- Record dot syntax

rnExpr (HsGetField XGetField GhcPs
_ LHsExpr GhcPs
e XRec GhcPs (DotFieldOcc GhcPs)
f)
 = do { (getField, fv_getField) <- Name -> RnM (Name, FreeVars)
lookupSyntaxName Name
getFieldName
      ; (e, fv_e) <- rnLExpr e
      ; let f' = LocatedAn NoEpAnns (DotFieldOcc GhcPs)
-> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
rnDotFieldOcc XRec GhcPs (DotFieldOcc GhcPs)
LocatedAn NoEpAnns (DotFieldOcc GhcPs)
f
      ; return ( mkExpandedExpr
                   (HsGetField noExtField e f')
                   (mkGetField getField e (fmap (unLoc . dfoLabel) f'))
               , fv_e `plusFV` fv_getField ) }

rnExpr (HsProjection XProjection GhcPs
_ NonEmpty (XRec GhcPs (DotFieldOcc GhcPs))
fs)
  = do { (getField, fv_getField) <- Name -> RnM (Name, FreeVars)
lookupSyntaxName Name
getFieldName
       ; circ <- lookupOccRn compose_RDR
       ; let fs' = (LocatedAn NoEpAnns (DotFieldOcc GhcPs)
 -> LocatedAn NoEpAnns (DotFieldOcc GhcRn))
-> NonEmpty (LocatedAn NoEpAnns (DotFieldOcc GhcPs))
-> NonEmpty (LocatedAn NoEpAnns (DotFieldOcc GhcRn))
forall a b. (a -> b) -> NonEmpty a -> NonEmpty b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap LocatedAn NoEpAnns (DotFieldOcc GhcPs)
-> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
rnDotFieldOcc NonEmpty (XRec GhcPs (DotFieldOcc GhcPs))
NonEmpty (LocatedAn NoEpAnns (DotFieldOcc GhcPs))
fs
       ; return ( mkExpandedExpr
                    (HsProjection noExtField fs')
                    (mkProjection getField circ (fmap (fmap (unLoc . dfoLabel)) fs'))
                , unitFV circ `plusFV` fv_getField) }

------------------------------------------
-- Template Haskell extensions
rnExpr e :: HsExpr GhcPs
e@(HsTypedBracket XTypedBracket GhcPs
_ LHsExpr GhcPs
br_body)   = HsExpr GhcPs -> LHsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnTypedBracket HsExpr GhcPs
e LHsExpr GhcPs
br_body
rnExpr e :: HsExpr GhcPs
e@(HsUntypedBracket XUntypedBracket GhcPs
_ HsQuote GhcPs
br_body) = HsExpr GhcPs -> HsQuote GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnUntypedBracket HsExpr GhcPs
e HsQuote GhcPs
br_body

rnExpr (HsTypedSplice   XTypedSplice GhcPs
_ LHsExpr GhcPs
splice) = LHsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnTypedSplice LHsExpr GhcPs
splice
rnExpr (HsUntypedSplice XUntypedSplice GhcPs
_ HsUntypedSplice GhcPs
splice) = HsUntypedSplice GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnUntypedSpliceExpr HsUntypedSplice GhcPs
splice

---------------------------------------------
--      Sections
-- See Note [Parsing sections] in GHC.Parser
rnExpr (HsPar XPar GhcPs
_ (L SrcSpanAnnA
loc (section :: HsExpr GhcPs
section@(SectionL {}))))
  = do  { (section', fvs) <- HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnSection HsExpr GhcPs
section
        ; return (HsPar noExtField (L loc section'), fvs) }

rnExpr (HsPar XPar GhcPs
_ (L SrcSpanAnnA
loc (section :: HsExpr GhcPs
section@(SectionR {}))))
  = do  { (section', fvs) <- HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnSection HsExpr GhcPs
section
        ; return (HsPar noExtField (L loc section'), fvs) }

rnExpr (HsPar XPar GhcPs
_ LHsExpr GhcPs
e)
  = do  { (e', fvs_e) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
e
        ; return (HsPar noExtField e', fvs_e) }

rnExpr expr :: HsExpr GhcPs
expr@(SectionL {})
  = do  { TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (HsExpr GhcPs -> TcRnMessage
sectionErr HsExpr GhcPs
expr); HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnSection HsExpr GhcPs
expr }
rnExpr expr :: HsExpr GhcPs
expr@(SectionR {})
  = do  { TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (HsExpr GhcPs -> TcRnMessage
sectionErr HsExpr GhcPs
expr); HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnSection HsExpr GhcPs
expr }

---------------------------------------------
rnExpr (HsPragE XPragE GhcPs
x HsPragE GhcPs
prag LHsExpr GhcPs
expr)
  = do { (expr', fvs_expr) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
       ; return (HsPragE x (rn_prag prag) expr', fvs_expr) }
  where
    rn_prag :: HsPragE GhcPs -> HsPragE GhcRn
    rn_prag :: HsPragE GhcPs -> HsPragE GhcRn
rn_prag (HsPragSCC XSCC GhcPs
x StringLiteral
ann) = XSCC GhcRn -> StringLiteral -> HsPragE GhcRn
forall p. XSCC p -> StringLiteral -> HsPragE p
HsPragSCC XSCC GhcPs
XSCC GhcRn
x StringLiteral
ann

rnExpr (HsLam XLam GhcPs
x HsLamVariant
lam_variant MatchGroup GhcPs (LHsExpr GhcPs)
matches)
  = do { (matches', fvs_ms) <- HsMatchContextRn
-> (GenLocated SrcSpanAnnA (HsExpr GhcPs)
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars))
-> MatchGroup GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)),
      FreeVars)
forall (body :: * -> *).
(Outputable (body GhcPs), AnnoBody body) =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
-> MatchGroup GhcPs (LocatedA (body GhcPs))
-> RnM (MatchGroup GhcRn (LocatedA (body GhcRn)), FreeVars)
rnMatchGroup (HsLamVariant -> HsMatchContext (GenLocated SrcSpanAnnN Name)
forall fn. HsLamVariant -> HsMatchContext fn
LamAlt HsLamVariant
lam_variant) LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
GenLocated SrcSpanAnnA (HsExpr GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
rnLExpr MatchGroup GhcPs (LHsExpr GhcPs)
MatchGroup GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))
matches
       ; return (HsLam x lam_variant matches', fvs_ms) }

rnExpr (HsCase XCase GhcPs
_ LHsExpr GhcPs
expr MatchGroup GhcPs (LHsExpr GhcPs)
matches)
  = do { (new_expr, e_fvs) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
       ; (new_matches, ms_fvs) <- rnMatchGroup CaseAlt rnLExpr matches
       ; return (HsCase CaseAlt new_expr new_matches, e_fvs `plusFV` ms_fvs) }

rnExpr (HsLet XLet GhcPs
_ HsLocalBinds GhcPs
binds LHsExpr GhcPs
expr)
  = HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> FreeVars -> TcM (HsExpr GhcRn, FreeVars))
-> TcM (HsExpr GhcRn, FreeVars)
forall result.
HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> FreeVars -> RnM (result, FreeVars))
-> RnM (result, FreeVars)
rnLocalBindsAndThen HsLocalBinds GhcPs
binds ((HsLocalBinds GhcRn -> FreeVars -> TcM (HsExpr GhcRn, FreeVars))
 -> TcM (HsExpr GhcRn, FreeVars))
-> (HsLocalBinds GhcRn -> FreeVars -> TcM (HsExpr GhcRn, FreeVars))
-> TcM (HsExpr GhcRn, FreeVars)
forall a b. (a -> b) -> a -> b
$ \HsLocalBinds GhcRn
binds' FreeVars
_ -> do
      { (expr',fvExpr) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
      ; return (HsLet noExtField binds' expr', fvExpr) }

rnExpr (HsDo XDo GhcPs
_ HsDoFlavour
do_or_lc (L SrcSpanAnnL
l [GenLocated
   SrcSpanAnnA
   (StmtLR GhcPs GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
stmts))
 = do { ((stmts1, _), fvs1) <-
          HsStmtContextRn
-> (HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars))
-> [LStmt GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))]
-> ([Name] -> RnM ((), FreeVars))
-> RnM
     (([(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)),
         FreeVars)],
       ()),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmtsWithFreeVars (HsDoFlavour -> HsStmtContext (GenLocated SrcSpanAnnN Name)
forall fn. HsDoFlavour -> HsStmtContext fn
HsDoStmt HsDoFlavour
do_or_lc) HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnExpr [LStmt GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcPs GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
stmts
            (\ [Name]
_ -> ((), FreeVars) -> RnM ((), FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ((), FreeVars
emptyFVs))
      ; (pp_stmts, fvs2) <- postProcessStmtsForApplicativeDo do_or_lc stmts1
      ; return ( HsDo noExtField do_or_lc (L l pp_stmts), fvs1 `plusFV` fvs2 ) }
-- ExplicitList: see Note [Handling overloaded and rebindable constructs]
rnExpr (ExplicitList XExplicitList GhcPs
_ [LHsExpr GhcPs]
exps)
  = do  { (exps', fvs) <- [LHsExpr GhcPs] -> RnM ([XRec GhcRn (HsExpr GhcRn)], FreeVars)
rnExprs [LHsExpr GhcPs]
exps
        ; opt_OverloadedLists <- xoptM LangExt.OverloadedLists
        ; if not opt_OverloadedLists
          then return  (ExplicitList noExtField exps', fvs)
          else
    do { (from_list_n_name, fvs') <- lookupSyntaxName fromListNName
       ; loc <- getSrcSpanM -- See Note [Source locations for implicit function calls]
       ; let rn_list  = XExplicitList GhcRn -> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
forall p. XExplicitList p -> [LHsExpr p] -> HsExpr p
ExplicitList XExplicitList GhcRn
NoExtField
noExtField [XRec GhcRn (HsExpr GhcRn)]
[GenLocated SrcSpanAnnA (HsExpr GhcRn)]
exps'
             lit_n    = Int -> IntegralLit
forall a. Integral a => a -> IntegralLit
mkIntegralLit ([GenLocated SrcSpanAnnA (HsExpr GhcPs)] -> Int
forall a. [a] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [LHsExpr GhcPs]
[GenLocated SrcSpanAnnA (HsExpr GhcPs)]
exps)
             hs_lit   = IntegralLit -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an. NoAnn an => IntegralLit -> LocatedAn an (HsExpr GhcRn)
genHsIntegralLit IntegralLit
lit_n
             exp_list = GenLocated SrcSpanAnnN Name
-> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
genHsApps' (SrcSpanAnnN -> Name -> GenLocated SrcSpanAnnN Name
forall l e. l -> e -> GenLocated l e
L (SrcSpan -> SrcSpanAnnN
forall e. HasAnnotation e => SrcSpan -> e
noAnnSrcSpan SrcSpan
loc) Name
from_list_n_name) [XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
hs_lit, HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan HsExpr GhcRn
rn_list]
       ; return ( mkExpandedExpr rn_list exp_list
                , fvs `plusFV` fvs') } }

rnExpr (ExplicitTuple XExplicitTuple GhcPs
_ [HsTupArg GhcPs]
tup_args Boxity
boxity)
  = do { [HsTupArg GhcPs] -> IOEnv (Env TcGblEnv TcLclEnv) ()
checkTupleSection [HsTupArg GhcPs]
tup_args
       ; (tup_args', fvs) <- (HsTupArg GhcPs
 -> IOEnv (Env TcGblEnv TcLclEnv) (HsTupArg GhcRn, FreeVars))
-> [HsTupArg GhcPs]
-> IOEnv (Env TcGblEnv TcLclEnv) ([HsTupArg GhcRn], [FreeVars])
forall (m :: * -> *) a b c.
Applicative m =>
(a -> m (b, c)) -> [a] -> m ([b], [c])
mapAndUnzipM HsTupArg GhcPs
-> IOEnv (Env TcGblEnv TcLclEnv) (HsTupArg GhcRn, FreeVars)
rnTupArg [HsTupArg GhcPs]
tup_args
       ; return (ExplicitTuple noExtField tup_args' boxity, plusFVs fvs) }
  where
    rnTupArg :: HsTupArg GhcPs
-> IOEnv (Env TcGblEnv TcLclEnv) (HsTupArg GhcRn, FreeVars)
rnTupArg (Present XPresent GhcPs
x LHsExpr GhcPs
e) = do { (e',fvs) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
e
                                ; return (Present x e', fvs) }
    rnTupArg (Missing XMissing GhcPs
_) = (HsTupArg GhcRn, FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (HsTupArg GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XMissing GhcRn -> HsTupArg GhcRn
forall id. XMissing id -> HsTupArg id
Missing XMissing GhcRn
NoExtField
noExtField, FreeVars
emptyFVs)

rnExpr (ExplicitSum XExplicitSum GhcPs
_ Int
alt Int
arity LHsExpr GhcPs
expr)
  = do { (expr', fvs) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
       ; return (ExplicitSum noExtField alt arity expr', fvs) }

rnExpr (RecordCon { rcon_con :: forall p. HsExpr p -> XRec p (ConLikeP p)
rcon_con = XRec GhcPs (ConLikeP GhcPs)
con_id
                  , rcon_flds :: forall p. HsExpr p -> HsRecordBinds p
rcon_flds = rec_binds :: HsRecordBinds GhcPs
rec_binds@(HsRecFields { rec_dotdot :: forall p arg. HsRecFields p arg -> Maybe (XRec p RecFieldsDotDot)
rec_dotdot = Maybe (XRec GhcPs RecFieldsDotDot)
dd }) })
  = do { con_lname@(L _ con_name) <- GenLocated SrcSpanAnnN RdrName
-> TcRn (GenLocated SrcSpanAnnN Name)
forall ann.
GenLocated (EpAnn ann) RdrName
-> TcRn (GenLocated (EpAnn ann) Name)
lookupLocatedOccRnConstr XRec GhcPs (ConLikeP GhcPs)
GenLocated SrcSpanAnnN RdrName
con_id
       ; (flds, fvs)   <- rnHsRecFields (HsRecFieldCon con_name) mk_hs_var rec_binds
       ; (flds', fvss) <- mapAndUnzipM rn_field flds
       ; let rec_binds' = HsRecFields { rec_flds :: [LHsRecField GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))]
rec_flds = [LHsRecField GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))]
[GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated SrcSpanAnnA (FieldOcc GhcRn))
      (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
flds', rec_dotdot :: Maybe (XRec GhcRn RecFieldsDotDot)
rec_dotdot = Maybe (XRec GhcPs RecFieldsDotDot)
Maybe (XRec GhcRn RecFieldsDotDot)
dd }
       ; return (RecordCon { rcon_ext = noExtField
                           , rcon_con = con_lname, rcon_flds = rec_binds' }
                , fvs `plusFV` plusFVs fvss `addOneFV` con_name) }
  where
    mk_hs_var :: SrcSpan -> IdP p -> HsExpr p
mk_hs_var SrcSpan
l IdP p
n = XVar p -> XRec p (IdP p) -> HsExpr p
forall p. XVar p -> LIdP p -> HsExpr p
HsVar XVar p
NoExtField
noExtField (l -> IdP p -> GenLocated l (IdP p)
forall l e. l -> e -> GenLocated l e
L (SrcSpan -> l
forall e. HasAnnotation e => SrcSpan -> e
noAnnSrcSpan SrcSpan
l) IdP p
n)
    rn_field :: GenLocated
  l (HsFieldBind lhs (GenLocated SrcSpanAnnA (HsExpr GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        l (HsFieldBind lhs (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
rn_field (L l
l HsFieldBind lhs (GenLocated SrcSpanAnnA (HsExpr GhcPs))
fld) = do { (arg', fvs) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr (HsFieldBind lhs (GenLocated SrcSpanAnnA (HsExpr GhcPs))
-> GenLocated SrcSpanAnnA (HsExpr GhcPs)
forall lhs rhs. HsFieldBind lhs rhs -> rhs
hfbRHS HsFieldBind lhs (GenLocated SrcSpanAnnA (HsExpr GhcPs))
fld)
                            ; return (L l (fld { hfbRHS = arg' }), fvs) }

rnExpr (RecordUpd { rupd_expr :: forall p. HsExpr p -> LHsExpr p
rupd_expr = L SrcSpanAnnA
l HsExpr GhcPs
expr, rupd_flds :: forall p. HsExpr p -> LHsRecUpdFields p
rupd_flds = LHsRecUpdFields GhcPs
rbinds })
  = SrcSpanAnnA
-> TcM (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall ann a. EpAnn ann -> TcRn a -> TcRn a
setSrcSpanA SrcSpanAnnA
l (TcM (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars))
-> TcM (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a b. (a -> b) -> a -> b
$
    case LHsRecUpdFields GhcPs
rbinds of

      -- 'OverloadedRecordUpdate' is not in effect. Regular record update.
      RegularRecUpdFields { recUpdFields :: forall p. LHsRecUpdFields p -> [LHsRecUpdField p p]
recUpdFields = [LHsRecUpdField GhcPs GhcPs]
flds } ->
        do  { (e, fv_e) <- HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnExpr HsExpr GhcPs
expr
            ; (parents, flds, fv_flds) <- rnHsRecUpdFields flds
            ; let upd_flds =
                    RegularRecUpdFields
                    { xRecUpdFields :: XLHsRecUpdLabels GhcRn
xRecUpdFields = NonEmpty (HsRecUpdParent GhcRn)
XLHsRecUpdLabels GhcRn
parents
                    , recUpdFields :: [LHsRecUpdField GhcRn GhcRn]
recUpdFields  = [LHsRecUpdField GhcRn GhcRn]
[GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated SrcSpanAnnA (AmbiguousFieldOcc GhcRn))
      (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
flds }
            ; return ( RecordUpd noExtField (L l e) upd_flds
                     , fv_e `plusFV` fv_flds ) }

      -- 'OverloadedRecordUpdate' is in effect. Record dot update desugaring.
      OverloadedRecUpdFields { olRecUpdFields :: forall p. LHsRecUpdFields p -> [LHsRecUpdProj p]
olRecUpdFields = [LHsRecUpdProj GhcPs]
flds } ->
        do { Extension
-> IOEnv (Env TcGblEnv TcLclEnv) ()
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall gbl lcl. Extension -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
unlessXOptM Extension
LangExt.RebindableSyntax (IOEnv (Env TcGblEnv TcLclEnv) ()
 -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> IOEnv (Env TcGblEnv TcLclEnv) ()
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$
               TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr TcRnMessage
TcRnNoRebindableSyntaxRecordDot
           ; let punnedFields :: [HsFieldBind
   (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
   (GenLocated SrcSpanAnnA (HsExpr GhcPs))]
punnedFields = [HsFieldBind
  (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
  (GenLocated SrcSpanAnnA (HsExpr GhcPs))
fld | (L SrcSpanAnnA
_ HsFieldBind
  (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
  (GenLocated SrcSpanAnnA (HsExpr GhcPs))
fld) <- [LHsRecUpdProj GhcPs]
[GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
      (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
flds, HsFieldBind
  (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
  (GenLocated SrcSpanAnnA (HsExpr GhcPs))
-> Bool
forall lhs rhs. HsFieldBind lhs rhs -> Bool
hfbPun HsFieldBind
  (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
  (GenLocated SrcSpanAnnA (HsExpr GhcPs))
fld]
           ; punsEnabled <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.NamedFieldPuns
           ; unless (null punnedFields || punsEnabled) $
               addErr TcRnNoFieldPunsRecordDot
           ; (getField, fv_getField) <- lookupSyntaxName getFieldName
           ; (setField, fv_setField) <- lookupSyntaxName setFieldName
           ; (e, fv_e) <- rnExpr expr
           ; (us, fv_us) <- rnHsUpdProjs flds
            ; let upd_flds = OverloadedRecUpdFields
                            { xOLRecUpdFields :: XLHsOLRecUpdLabels GhcRn
xOLRecUpdFields = XLHsOLRecUpdLabels GhcRn
NoExtField
noExtField
                            , olRecUpdFields :: [LHsRecUpdProj GhcRn]
olRecUpdFields  = [LHsRecUpdProj GhcRn]
[GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
      (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
us }
            ; return ( mkExpandedExpr
                         (RecordUpd noExtField (L l e) upd_flds)
                         (mkRecordDotUpd getField setField (L l e) us)
                        , plusFVs [fv_getField, fv_setField, fv_e, fv_us] ) }

rnExpr (HsRecSel XRecSel GhcPs
x FieldOcc GhcPs
_) = DataConCantHappen -> TcM (HsExpr GhcRn, FreeVars)
forall a. DataConCantHappen -> a
dataConCantHappen XRecSel GhcPs
DataConCantHappen
x

rnExpr (ExprWithTySig XExprWithTySig GhcPs
_ LHsExpr GhcPs
expr LHsSigWcType (NoGhcTc GhcPs)
pty)
  = do  { (pty', fvTy)    <- HsDocContext
-> LHsSigWcType GhcPs -> RnM (LHsSigWcType GhcRn, FreeVars)
rnHsSigWcType HsDocContext
ExprWithTySigCtx LHsSigWcType (NoGhcTc GhcPs)
LHsSigWcType GhcPs
pty
        ; (expr', fvExpr) <- bindSigTyVarsFV (hsWcScopedTvs pty') $
                             rnLExpr expr
        ; return (ExprWithTySig noExtField expr' pty', fvExpr `plusFV` fvTy) }

-- HsIf: see Note [Handling overloaded and rebindable constructs]
-- Because of the coverage checker it is most convenient /not/ to
-- expand HsIf; unless we are in rebindable syntax.
rnExpr (HsIf XIf GhcPs
_ LHsExpr GhcPs
p LHsExpr GhcPs
b1 LHsExpr GhcPs
b2) = LHsExpr GhcPs
-> LHsExpr GhcPs -> LHsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnHsIf LHsExpr GhcPs
p LHsExpr GhcPs
b1 LHsExpr GhcPs
b2

rnExpr (HsMultiIf XMultiIf GhcPs
_ [LGRHS GhcPs (LHsExpr GhcPs)]
alts)
  = do { (alts', fvs) <- (GenLocated
   (Anno (GRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))))
   (GRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs)))
 -> RnM
      (GenLocated
         (Anno (GRHS GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
         (GRHS GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars))
-> [GenLocated
      (Anno (GRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))))
      (GRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
-> RnM
     ([GenLocated
         (Anno (GRHS GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
         (GRHS GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
      FreeVars)
forall (f :: * -> *) a b.
Traversable f =>
(a -> RnM (b, FreeVars)) -> f a -> RnM (f b, FreeVars)
mapFvRn (HsMatchContextRn
-> (GenLocated SrcSpanAnnA (HsExpr GhcPs)
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars))
-> LGRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))
-> RnM
     (LGRHS GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)
forall (body :: * -> *).
AnnoBody body =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
-> LGRHS GhcPs (LocatedA (body GhcPs))
-> RnM (LGRHS GhcRn (LocatedA (body GhcRn)), FreeVars)
rnGRHS HsMatchContextRn
HsMatchContext (GenLocated SrcSpanAnnN Name)
forall fn. HsMatchContext fn
IfAlt LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
GenLocated SrcSpanAnnA (HsExpr GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
rnLExpr) [LGRHS GhcPs (LHsExpr GhcPs)]
[GenLocated
   (Anno (GRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))))
   (GRHS GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
alts
       ; return (HsMultiIf noExtField alts', fvs) }

rnExpr (ArithSeq XArithSeq GhcPs
_ Maybe (SyntaxExpr GhcPs)
_ ArithSeqInfo GhcPs
seq)
  = do { opt_OverloadedLists <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.OverloadedLists
       ; (new_seq, fvs) <- rnArithSeq seq
       ; if opt_OverloadedLists
           then do {
            ; (from_list_name, fvs') <- lookupSyntax fromListName
            ; return (ArithSeq noExtField (Just from_list_name) new_seq
                     , fvs `plusFV` fvs') }
           else
            return (ArithSeq noExtField Nothing new_seq, fvs) }

rnExpr (HsEmbTy XEmbTy GhcPs
_ LHsWcType (NoGhcTc GhcPs)
ty)
  = do { (ty', fvs) <- HsDocContext -> LHsWcType GhcPs -> RnM (LHsWcType GhcRn, FreeVars)
rnHsWcType HsDocContext
HsTypeCtx LHsWcType (NoGhcTc GhcPs)
LHsWcType GhcPs
ty
       ; return (HsEmbTy noExtField ty', fvs) }

{-
************************************************************************
*                                                                      *
        Static values
*                                                                      *
************************************************************************

For the static form we check that it is not used in splices.
We also collect the free variables of the term which come from
this module. See Note [Grand plan for static forms] in GHC.Iface.Tidy.StaticPtrTable.
-}

rnExpr e :: HsExpr GhcPs
e@(HsStatic XStatic GhcPs
_ LHsExpr GhcPs
expr) = do
    -- Normally, you wouldn't be able to construct a static expression without
    -- first enabling -XStaticPointers in the first place, since that extension
    -- is what makes the parser treat `static` as a keyword. But this is not a
    -- sufficient safeguard, as one can construct static expressions by another
    -- mechanism: Template Haskell (see #14204). To ensure that GHC is
    -- absolutely prepared to cope with static forms, we check for
    -- -XStaticPointers here as well.
    Extension
-> IOEnv (Env TcGblEnv TcLclEnv) ()
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall gbl lcl. Extension -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
unlessXOptM Extension
LangExt.StaticPointers (IOEnv (Env TcGblEnv TcLclEnv) ()
 -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> IOEnv (Env TcGblEnv TcLclEnv) ()
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$
      TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$ HsExpr GhcPs -> TcRnMessage
TcRnIllegalStaticExpression HsExpr GhcPs
e
    (expr',fvExpr) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
    stage <- getStage
    case stage of
      Splice SpliceType
_ -> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$ THError -> TcRnMessage
TcRnTHError (THError -> TcRnMessage) -> THError -> TcRnMessage
forall a b. (a -> b) -> a -> b
$ HsExpr GhcPs -> THError
IllegalStaticFormInSplice HsExpr GhcPs
e
      ThStage
_        -> () -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
    mod <- getModule
    let fvExpr' = (Name -> Bool) -> FreeVars -> FreeVars
filterNameSet (Module -> Name -> Bool
nameIsLocalOrFrom Module
mod) FreeVars
fvExpr
    return (HsStatic fvExpr' expr', fvExpr)

{-
************************************************************************
*                                                                      *
        Arrow notation
*                                                                      *
********************************************************************* -}

rnExpr (HsProc XProc GhcPs
x LPat GhcPs
pat LHsCmdTop GhcPs
body)
  = TcM (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. TcM a -> TcM a
newArrowScope (TcM (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars))
-> TcM (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a b. (a -> b) -> a -> b
$
    HsMatchContextRn
-> LPat GhcPs
-> (LPat GhcRn -> TcM (HsExpr GhcRn, FreeVars))
-> TcM (HsExpr GhcRn, FreeVars)
forall a.
HsMatchContextRn
-> LPat GhcPs
-> (LPat GhcRn -> RnM (a, FreeVars))
-> RnM (a, FreeVars)
rnPat (HsArrowMatchContext -> HsMatchContext (GenLocated SrcSpanAnnN Name)
forall fn. HsArrowMatchContext -> HsMatchContext fn
ArrowMatchCtxt HsArrowMatchContext
ProcExpr) LPat GhcPs
pat ((LPat GhcRn -> TcM (HsExpr GhcRn, FreeVars))
 -> TcM (HsExpr GhcRn, FreeVars))
-> (LPat GhcRn -> TcM (HsExpr GhcRn, FreeVars))
-> TcM (HsExpr GhcRn, FreeVars)
forall a b. (a -> b) -> a -> b
$ \ LPat GhcRn
pat' -> do
      { (body',fvBody) <- LHsCmdTop GhcPs -> RnM (LHsCmdTop GhcRn, FreeVars)
rnCmdTop LHsCmdTop GhcPs
body
      ; return (HsProc x pat' body', fvBody) }

{-
************************************************************************
*                                                                      *
        Operator sections
*                                                                      *
********************************************************************* -}


rnSection :: HsExpr GhcPs -> RnM (HsExpr GhcRn, FreeVars)
-- See Note [Parsing sections] in GHC.Parser
-- Also see Note [Handling overloaded and rebindable constructs]

rnSection :: HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnSection section :: HsExpr GhcPs
section@(SectionR XSectionR GhcPs
x LHsExpr GhcPs
op LHsExpr GhcPs
expr)
  -- See Note [Left and right sections]
  = do  { (op', fvs_op)     <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
op
        ; (expr', fvs_expr) <- rnLExpr expr
        ; checkSectionPrec InfixR section op' expr'
        ; let rn_section = XSectionR GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XSectionR p -> LHsExpr p -> LHsExpr p -> HsExpr p
SectionR XSectionR GhcPs
XSectionR GhcRn
x XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op' XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
expr'
              ds_section = Name -> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
genHsApps Name
rightSectionName [XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op',XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
expr']
        ; return ( mkExpandedExpr rn_section ds_section
                 , fvs_op `plusFV` fvs_expr) }

rnSection section :: HsExpr GhcPs
section@(SectionL XSectionL GhcPs
x LHsExpr GhcPs
expr LHsExpr GhcPs
op)
  -- See Note [Left and right sections]
  = do  { (expr', fvs_expr) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
        ; (op', fvs_op)     <- rnLExpr op
        ; checkSectionPrec InfixL section op' expr'
        ; postfix_ops <- xoptM LangExt.PostfixOperators
                        -- Note [Left and right sections]
        ; let rn_section = XSectionL GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XSectionL p -> LHsExpr p -> LHsExpr p -> HsExpr p
SectionL XSectionL GhcPs
XSectionL GhcRn
x XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
expr' XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op'
              ds_section
                | Bool
postfix_ops = XApp GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XApp p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsApp XApp GhcRn
NoExtField
noExtField XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op' XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
expr'
                | Bool
otherwise   = Name -> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
genHsApps Name
leftSectionName
                                   [HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan (HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall a b. (a -> b) -> a -> b
$ XApp GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XApp p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsApp XApp GhcRn
NoExtField
noExtField XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op' XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
expr']
        ; return ( mkExpandedExpr rn_section ds_section
                 , fvs_op `plusFV` fvs_expr) }

rnSection HsExpr GhcPs
other = String -> SDoc -> TcM (HsExpr GhcRn, FreeVars)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rnSection" (HsExpr GhcPs -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcPs
other)

{- Note [Left and right sections]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dealing with left sections (x *) and right sections (* x) is
surprisingly fiddly.  We expand like this
     (`op` e) ==> rightSection op e
     (e `op`) ==> leftSection  (op e)

Using an auxiliary function in this way avoids the awkwardness of
generating a lambda, esp if `e` is a redex, so we *don't* want
to generate `(\x -> op x e)`. See Historical
Note [Desugaring operator sections]

Here are their definitions:
   leftSection :: forall r1 r2 n (a::TYPE r1) (b::TYPE r2).
                  (a %n-> b) -> a %n-> b
   leftSection f x = f x

   rightSection :: forall r1 r2 r3 n1 n2 (a::TYPE r1) (b::TYPE r2) (c::TYPE r3).
                   (a %n1 -> b %n2-> c) -> b %n2-> a %n1-> c
   rightSection f y x = f x y

Note the wrinkles:

* We do /not/ use lookupSyntaxName, which would make left and right
  section fall under RebindableSyntax.  Reason: it would be a user-
  facing change, and there are some tricky design choices (#19354).
  Plus, infix operator applications would be trickier to make
  rebindable, so it'd be inconsistent to do so for sections.

  TL;DR: we still use the renamer-expansion mechanism for operator
  sections, but only to eliminate special-purpose code paths in the
  renamer and desugarer.

* leftSection and rightSection must be representation-polymorphic, to allow
  (+# 4#) and (4# +#) to work. See
  Note [Wired-in Ids for rebindable syntax] in GHC.Types.Id.Make.

* leftSection and rightSection must be multiplicity-polymorphic.
  (Test linear/should_compile/OldList showed this up.)

* Because they are representation-polymorphic, we have to define them
  as wired-in Ids, with compulsory inlining.  See
  GHC.Types.Id.Make.leftSectionId, rightSectionId.

* leftSection is just ($) really; but unlike ($) it is
  representation-polymorphic in the result type, so we can write
  `(x +#)`, say.

* The type of leftSection must have an arrow in its first argument,
  because (x `ord`) should be rejected, because ord does not take two
  arguments

* It's important that we define leftSection in an eta-expanded way,
  (i.e. not leftSection f = f), so that
      (True `undefined`) `seq` ()
      = (leftSection (undefined True) `seq` ())
  evaluates to () and not undefined

* If PostfixOperators is ON, then we expand a left section like this:
      (e `op`)  ==>   op e
  with no auxiliary function at all.  Simple!

* leftSection and rightSection switch on ImpredicativeTypes locally,
  during Quick Look; see GHC.Tc.Gen.App.wantQuickLook. Consider
  test DeepSubsumption08:
     type Setter st t a b = forall f. Identical f => blah
     (.~) :: Setter s t a b -> b -> s -> t
     clear :: Setter a a' b (Maybe b') -> a -> a'
     clear = (.~ Nothing)
   The expansion look like (rightSection (.~) Nothing).  So we must
   instantiate `rightSection` first type argument to a polytype!
   Hence the special magic in App.wantQuickLook.

Historical Note [Desugaring operator sections]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This Note explains some historical trickiness in desugaring left and
right sections.  That trickiness has completely disappeared now that
we desugar to calls to 'leftSection` and `rightSection`, but I'm
leaving it here to remind us how nice the new story is.

Desugaring left sections with -XPostfixOperators is straightforward: convert
(expr `op`) to (op expr).

Without -XPostfixOperators it's a bit more tricky. At first it looks as if we
can convert

    (expr `op`)

naively to

    \x -> op expr x

But no!  expr might be a redex, and we can lose laziness badly this
way.  Consider

    map (expr `op`) xs

for example. If expr were a redex then eta-expanding naively would
result in multiple evaluations where the user might only have expected one.

So we convert instead to

    let y = expr in \x -> op y x

Also, note that we must do this for both right and (perhaps surprisingly) left
sections. Why are left sections necessary? Consider the program (found in #18151),

    seq (True `undefined`) ()

according to the Haskell Report this should reduce to () (as it specifies
desugaring via eta expansion). However, if we fail to eta expand we will rather
bottom. Consequently, we must eta expand even in the case of a left section.

If `expr` is actually just a variable, say, then the simplifier
will inline `y`, eliminating the redundant `let`.

Note that this works even in the case that `expr` is unlifted. In this case
bindNonRec will automatically do the right thing, giving us:

    case expr of y -> (\x -> op y x)

See #18151.

Note [Reporting unbound names]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Faced with an out-of-scope `RdrName` there are two courses of action
A. Report an error immediately (and return a HsUnboundVar). This will halt GHC after the renamer is complete
B. Return a HsUnboundVar without reporting an error.  That will allow the typechecker to run, which in turn
   can give a better error message, notably giving the type of the variable via the "typed holes" mechanism.

When `-fdefer-out-of-scope-variables` is on we follow plan B.

When it is not, we follow plan B for unqualified names, and plan A for qualified names.

If a name is qualified, and out of scope, then by default an error will be raised
because the user was already more precise. They specified a specific qualification
and either
  * The qualification didn't exist, so that precision was wrong.
  * Or the qualification existed and the thing we were looking for wasn't where
    the qualification said it would be.

However we can still defer this error completely, and we do defer it if
`-fdefer-out-of-scope-variables` is enabled.

-}

{-
************************************************************************
*                                                                      *
        Field Labels
*                                                                      *
************************************************************************
-}

rnDotFieldOcc :: LocatedAn NoEpAnns (DotFieldOcc GhcPs) -> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
rnDotFieldOcc :: LocatedAn NoEpAnns (DotFieldOcc GhcPs)
-> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
rnDotFieldOcc (L EpAnn NoEpAnns
l (DotFieldOcc XCDotFieldOcc GhcPs
x XRec GhcPs FieldLabelString
label)) = EpAnn NoEpAnns
-> DotFieldOcc GhcRn -> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
forall l e. l -> e -> GenLocated l e
L EpAnn NoEpAnns
l (XCDotFieldOcc GhcRn
-> XRec GhcRn FieldLabelString -> DotFieldOcc GhcRn
forall p.
XCDotFieldOcc p -> XRec p FieldLabelString -> DotFieldOcc p
DotFieldOcc XCDotFieldOcc GhcPs
XCDotFieldOcc GhcRn
x XRec GhcPs FieldLabelString
XRec GhcRn FieldLabelString
label)

rnFieldLabelStrings :: FieldLabelStrings GhcPs -> FieldLabelStrings GhcRn
rnFieldLabelStrings :: FieldLabelStrings GhcPs -> FieldLabelStrings GhcRn
rnFieldLabelStrings (FieldLabelStrings [XRec GhcPs (DotFieldOcc GhcPs)]
fls) = [XRec GhcRn (DotFieldOcc GhcRn)] -> FieldLabelStrings GhcRn
forall p. [XRec p (DotFieldOcc p)] -> FieldLabelStrings p
FieldLabelStrings ((LocatedAn NoEpAnns (DotFieldOcc GhcPs)
 -> LocatedAn NoEpAnns (DotFieldOcc GhcRn))
-> [LocatedAn NoEpAnns (DotFieldOcc GhcPs)]
-> [LocatedAn NoEpAnns (DotFieldOcc GhcRn)]
forall a b. (a -> b) -> [a] -> [b]
map LocatedAn NoEpAnns (DotFieldOcc GhcPs)
-> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
rnDotFieldOcc [XRec GhcPs (DotFieldOcc GhcPs)]
[LocatedAn NoEpAnns (DotFieldOcc GhcPs)]
fls)

{-
************************************************************************
*                                                                      *
        Arrow commands
*                                                                      *
************************************************************************
-}

rnCmdArgs :: [LHsCmdTop GhcPs] -> RnM ([LHsCmdTop GhcRn], FreeVars)
rnCmdArgs :: [LHsCmdTop GhcPs] -> RnM ([LHsCmdTop GhcRn], FreeVars)
rnCmdArgs [] = ([GenLocated (EpAnn NoEpAnns) (HsCmdTop GhcRn)], FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated (EpAnn NoEpAnns) (HsCmdTop GhcRn)], FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ([], FreeVars
emptyFVs)
rnCmdArgs (LHsCmdTop GhcPs
arg:[LHsCmdTop GhcPs]
args)
  = do { (arg',fvArg) <- LHsCmdTop GhcPs -> RnM (LHsCmdTop GhcRn, FreeVars)
rnCmdTop LHsCmdTop GhcPs
arg
       ; (args',fvArgs) <- rnCmdArgs args
       ; return (arg':args', fvArg `plusFV` fvArgs) }

rnCmdTop :: LHsCmdTop GhcPs -> RnM (LHsCmdTop GhcRn, FreeVars)
rnCmdTop :: LHsCmdTop GhcPs -> RnM (LHsCmdTop GhcRn, FreeVars)
rnCmdTop = (HsCmdTop GhcPs -> TcM (HsCmdTop GhcRn, FreeVars))
-> GenLocated (EpAnn NoEpAnns) (HsCmdTop GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated (EpAnn NoEpAnns) (HsCmdTop GhcRn), FreeVars)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA HsCmdTop GhcPs -> TcM (HsCmdTop GhcRn, FreeVars)
rnCmdTop'
 where
  rnCmdTop' :: HsCmdTop GhcPs -> RnM (HsCmdTop GhcRn, FreeVars)
  rnCmdTop' :: HsCmdTop GhcPs -> TcM (HsCmdTop GhcRn, FreeVars)
rnCmdTop' (HsCmdTop XCmdTop GhcPs
_ LHsCmd GhcPs
cmd)
   = do { (cmd', fvCmd) <- LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
rnLCmd LHsCmd GhcPs
cmd
        ; let cmd_names = [Name
arrAName, Name
composeAName, Name
firstAName] [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++
                          FreeVars -> [Name]
nameSetElemsStable (HsCmd GhcRn -> FreeVars
methodNamesCmd (GenLocated SrcSpanAnnA (HsCmd GhcRn) -> HsCmd GhcRn
forall l e. GenLocated l e -> e
unLoc GenLocated SrcSpanAnnA (HsCmd GhcRn)
cmd'))
        -- Generate the rebindable syntax for the monad
        ; (cmd_names', cmd_fvs) <- lookupSyntaxNames cmd_names

        ; return (HsCmdTop (cmd_names `zip` cmd_names') cmd',
                  fvCmd `plusFV` cmd_fvs) }

rnLCmd :: LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
rnLCmd :: LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
rnLCmd = (HsCmd GhcPs -> TcM (HsCmd GhcRn, FreeVars))
-> GenLocated SrcSpanAnnA (HsCmd GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsCmd GhcRn), FreeVars)
forall a b c ann.
(a -> TcM (b, c))
-> GenLocated (EpAnn ann) a -> TcM (GenLocated (EpAnn ann) b, c)
wrapLocFstMA HsCmd GhcPs -> TcM (HsCmd GhcRn, FreeVars)
rnCmd

rnCmd :: HsCmd GhcPs -> RnM (HsCmd GhcRn, FreeVars)

rnCmd :: HsCmd GhcPs -> TcM (HsCmd GhcRn, FreeVars)
rnCmd (HsCmdArrApp XCmdArrApp GhcPs
_ LHsExpr GhcPs
arrow LHsExpr GhcPs
arg HsArrAppType
ho Bool
rtl)
  = do { (arrow',fvArrow) <- IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
select_arrow_scope (LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
arrow)
       ; (arg',fvArg) <- rnLExpr arg
       ; return (HsCmdArrApp noExtField arrow' arg' ho rtl,
                 fvArrow `plusFV` fvArg) }
  where
    select_arrow_scope :: IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
select_arrow_scope IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
tc = case HsArrAppType
ho of
        HsArrAppType
HsHigherOrderApp -> IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
tc
        HsArrAppType
HsFirstOrderApp  -> IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
forall a. TcM a -> TcM a
escapeArrowScope IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
tc
        -- See Note [Escaping the arrow scope] in GHC.Tc.Types
        -- Before renaming 'arrow', use the environment of the enclosing
        -- proc for the (-<) case.
        -- Local bindings, inside the enclosing proc, are not in scope
        -- inside 'arrow'.  In the higher-order case (-<<), they are.

-- infix form
rnCmd (HsCmdArrForm XCmdArrForm GhcPs
_ LHsExpr GhcPs
op LexicalFixity
_ (Just Fixity
_) [LHsCmdTop GhcPs
arg1, LHsCmdTop GhcPs
arg2])
  = do { (op',fv_op) <- IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
forall a. TcM a -> TcM a
escapeArrowScope (LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
op)
       ; let L _ (HsVar _ (L _ op_name)) = op'
       ; (arg1',fv_arg1) <- rnCmdTop arg1
       ; (arg2',fv_arg2) <- rnCmdTop arg2
        -- Deal with fixity
       ; fixity <- lookupFixityRn op_name
       ; final_e <- mkOpFormRn arg1' op' fixity arg2'
       ; return (final_e, fv_arg1 `plusFV` fv_op `plusFV` fv_arg2) }

rnCmd (HsCmdArrForm XCmdArrForm GhcPs
_ LHsExpr GhcPs
op LexicalFixity
f Maybe Fixity
fixity [LHsCmdTop GhcPs]
cmds)
  = do { (op',fvOp) <- IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
forall a. TcM a -> TcM a
escapeArrowScope (LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
op)
       ; (cmds',fvCmds) <- rnCmdArgs cmds
       ; return ( HsCmdArrForm noExtField op' f fixity cmds'
                , fvOp `plusFV` fvCmds) }

rnCmd (HsCmdApp XCmdApp GhcPs
x LHsCmd GhcPs
fun LHsExpr GhcPs
arg)
  = do { (fun',fvFun) <- LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
rnLCmd  LHsCmd GhcPs
fun
       ; (arg',fvArg) <- rnLExpr arg
       ; return (HsCmdApp x fun' arg', fvFun `plusFV` fvArg) }

rnCmd (HsCmdLam XCmdLamCase GhcPs
x HsLamVariant
lam_variant MatchGroup GhcPs (LHsCmd GhcPs)
matches)
  = do { let ctxt :: HsMatchContext (GenLocated SrcSpanAnnN Name)
ctxt = HsArrowMatchContext -> HsMatchContext (GenLocated SrcSpanAnnN Name)
forall fn. HsArrowMatchContext -> HsMatchContext fn
ArrowMatchCtxt (HsArrowMatchContext
 -> HsMatchContext (GenLocated SrcSpanAnnN Name))
-> HsArrowMatchContext
-> HsMatchContext (GenLocated SrcSpanAnnN Name)
forall a b. (a -> b) -> a -> b
$ HsLamVariant -> HsArrowMatchContext
ArrowLamAlt HsLamVariant
lam_variant
       ; (new_matches, ms_fvs) <- HsMatchContextRn
-> (GenLocated SrcSpanAnnA (HsCmd GhcPs)
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (GenLocated SrcSpanAnnA (HsCmd GhcRn), FreeVars))
-> MatchGroup GhcPs (GenLocated SrcSpanAnnA (HsCmd GhcPs))
-> RnM
     (MatchGroup GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)), FreeVars)
forall (body :: * -> *).
(Outputable (body GhcPs), AnnoBody body) =>
HsMatchContextRn
-> (LocatedA (body GhcPs) -> RnM (LocatedA (body GhcRn), FreeVars))
-> MatchGroup GhcPs (LocatedA (body GhcPs))
-> RnM (MatchGroup GhcRn (LocatedA (body GhcRn)), FreeVars)
rnMatchGroup HsMatchContextRn
HsMatchContext (GenLocated SrcSpanAnnN Name)
ctxt LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
GenLocated SrcSpanAnnA (HsCmd GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsCmd GhcRn), FreeVars)
rnLCmd MatchGroup GhcPs (LHsCmd GhcPs)
MatchGroup GhcPs (GenLocated SrcSpanAnnA (HsCmd GhcPs))
matches
       ; return (HsCmdLam x lam_variant new_matches, ms_fvs) }

rnCmd (HsCmdPar XCmdPar GhcPs
_ LHsCmd GhcPs
e)
  = do  { (e', fvs_e) <- LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
rnLCmd LHsCmd GhcPs
e
        ; return (HsCmdPar noExtField e', fvs_e) }

rnCmd (HsCmdCase XCmdCase GhcPs
_ LHsExpr GhcPs
expr MatchGroup GhcPs (LHsCmd GhcPs)
matches)
  = do { (new_expr, e_fvs) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
       ; (new_matches, ms_fvs) <- rnMatchGroup (ArrowMatchCtxt ArrowCaseAlt) rnLCmd matches
       ; return (HsCmdCase noExtField new_expr new_matches
                , e_fvs `plusFV` ms_fvs) }

rnCmd (HsCmdIf XCmdIf GhcPs
_ SyntaxExpr GhcPs
_ LHsExpr GhcPs
p LHsCmd GhcPs
b1 LHsCmd GhcPs
b2)
  = do { (p', fvP) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
p
       ; (b1', fvB1) <- rnLCmd b1
       ; (b2', fvB2) <- rnLCmd b2

       ; mb_ite <- lookupIfThenElse
       ; let (ite, fvITE) = case mb_ite of
                Just Name
ite_name -> (Name -> SyntaxExprRn
mkRnSyntaxExpr Name
ite_name, Name -> FreeVars
unitFV Name
ite_name)
                Maybe Name
Nothing       -> (SyntaxExprRn
NoSyntaxExprRn,          FreeVars
emptyFVs)

       ; return (HsCmdIf noExtField ite p' b1' b2', plusFVs [fvITE, fvP, fvB1, fvB2])}

rnCmd (HsCmdLet XCmdLet GhcPs
_ HsLocalBinds GhcPs
binds LHsCmd GhcPs
cmd)
  = HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> FreeVars -> TcM (HsCmd GhcRn, FreeVars))
-> TcM (HsCmd GhcRn, FreeVars)
forall result.
HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> FreeVars -> RnM (result, FreeVars))
-> RnM (result, FreeVars)
rnLocalBindsAndThen HsLocalBinds GhcPs
binds ((HsLocalBinds GhcRn -> FreeVars -> TcM (HsCmd GhcRn, FreeVars))
 -> TcM (HsCmd GhcRn, FreeVars))
-> (HsLocalBinds GhcRn -> FreeVars -> TcM (HsCmd GhcRn, FreeVars))
-> TcM (HsCmd GhcRn, FreeVars)
forall a b. (a -> b) -> a -> b
$ \ HsLocalBinds GhcRn
binds' FreeVars
_ -> do
      { (cmd',fvExpr) <- LHsCmd GhcPs -> RnM (LHsCmd GhcRn, FreeVars)
rnLCmd LHsCmd GhcPs
cmd
      ; return (HsCmdLet noExtField binds' cmd', fvExpr) }

rnCmd (HsCmdDo XCmdDo GhcPs
_ (L SrcSpanAnnL
l [GenLocated
   SrcSpanAnnA
   (StmtLR GhcPs GhcPs (GenLocated SrcSpanAnnA (HsCmd GhcPs)))]
stmts))
  = do  { ((stmts', _), fvs) <-
            HsStmtContextRn
-> (HsCmd GhcPs -> TcM (HsCmd GhcRn, FreeVars))
-> [LStmt GhcPs (GenLocated SrcSpanAnnA (HsCmd GhcPs))]
-> ([Name] -> RnM ((), FreeVars))
-> RnM
     (([LStmt GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn))], ()),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM (([LStmt GhcRn (LocatedA (body GhcRn))], thing), FreeVars)
rnStmts HsStmtContextRn
HsStmtContext (GenLocated SrcSpanAnnN Name)
forall fn. HsStmtContext fn
ArrowExpr HsCmd GhcPs -> TcM (HsCmd GhcRn, FreeVars)
rnCmd [LStmt GhcPs (GenLocated SrcSpanAnnA (HsCmd GhcPs))]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcPs GhcPs (GenLocated SrcSpanAnnA (HsCmd GhcPs)))]
stmts (\ [Name]
_ -> ((), FreeVars) -> RnM ((), FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ((), FreeVars
emptyFVs))
        ; return ( HsCmdDo noExtField (L l stmts'), fvs ) }

---------------------------------------------------
type CmdNeeds = FreeVars        -- Only inhabitants are
                                --      appAName, choiceAName, loopAName

-- find what methods the Cmd needs (loop, choice, apply)
methodNamesLCmd :: LHsCmd GhcRn -> CmdNeeds
methodNamesLCmd :: LHsCmd GhcRn -> FreeVars
methodNamesLCmd = HsCmd GhcRn -> FreeVars
methodNamesCmd (HsCmd GhcRn -> FreeVars)
-> (GenLocated SrcSpanAnnA (HsCmd GhcRn) -> HsCmd GhcRn)
-> GenLocated SrcSpanAnnA (HsCmd GhcRn)
-> FreeVars
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated SrcSpanAnnA (HsCmd GhcRn) -> HsCmd GhcRn
forall l e. GenLocated l e -> e
unLoc

methodNamesCmd :: HsCmd GhcRn -> CmdNeeds

methodNamesCmd :: HsCmd GhcRn -> FreeVars
methodNamesCmd (HsCmdArrApp XCmdArrApp GhcRn
_ XRec GhcRn (HsExpr GhcRn)
_arrow XRec GhcRn (HsExpr GhcRn)
_arg HsArrAppType
HsFirstOrderApp Bool
_rtl)
  = FreeVars
emptyFVs
methodNamesCmd (HsCmdArrApp XCmdArrApp GhcRn
_ XRec GhcRn (HsExpr GhcRn)
_arrow XRec GhcRn (HsExpr GhcRn)
_arg HsArrAppType
HsHigherOrderApp Bool
_rtl)
  = Name -> FreeVars
unitFV Name
appAName
methodNamesCmd (HsCmdArrForm {}) = FreeVars
emptyFVs

methodNamesCmd (HsCmdPar XCmdPar GhcRn
_ LHsCmd GhcRn
c) = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
c

methodNamesCmd (HsCmdIf XCmdIf GhcRn
_ SyntaxExpr GhcRn
_ XRec GhcRn (HsExpr GhcRn)
_ LHsCmd GhcRn
c1 LHsCmd GhcRn
c2)
  = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
c1 FreeVars -> FreeVars -> FreeVars
`plusFV` LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
c2 FreeVars -> Name -> FreeVars
`addOneFV` Name
choiceAName

methodNamesCmd (HsCmdLet XCmdLet GhcRn
_ HsLocalBinds GhcRn
_ LHsCmd GhcRn
c)          = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
c
methodNamesCmd (HsCmdDo XCmdDo GhcRn
_ (L SrcSpanAnnL
_ [GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
stmts))   = [CmdLStmt GhcRn] -> FreeVars
methodNamesStmts [CmdLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
stmts
methodNamesCmd (HsCmdApp XCmdApp GhcRn
_ LHsCmd GhcRn
c XRec GhcRn (HsExpr GhcRn)
_)          = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
c

methodNamesCmd (HsCmdCase XCmdCase GhcRn
_ XRec GhcRn (HsExpr GhcRn)
_ MatchGroup GhcRn (LHsCmd GhcRn)
matches)        = MatchGroup GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesMatch MatchGroup GhcRn (LHsCmd GhcRn)
matches FreeVars -> Name -> FreeVars
`addOneFV` Name
choiceAName
methodNamesCmd (HsCmdLam XCmdLamCase GhcRn
_ HsLamVariant
LamSingle MatchGroup GhcRn (LHsCmd GhcRn)
matches) = MatchGroup GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesMatch MatchGroup GhcRn (LHsCmd GhcRn)
matches
methodNamesCmd (HsCmdLam XCmdLamCase GhcRn
_ HsLamVariant
_         MatchGroup GhcRn (LHsCmd GhcRn)
matches) = MatchGroup GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesMatch MatchGroup GhcRn (LHsCmd GhcRn)
matches FreeVars -> Name -> FreeVars
`addOneFV` Name
choiceAName

--methodNamesCmd _ = emptyFVs
   -- Other forms can't occur in commands, but it's not convenient
   -- to error here so we just do what's convenient.
   -- The type checker will complain later

---------------------------------------------------
methodNamesMatch :: MatchGroup GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesMatch :: MatchGroup GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesMatch (MG { mg_alts :: forall p body. MatchGroup p body -> XRec p [LMatch p body]
mg_alts = L SrcSpanAnnL
_ [GenLocated
   SrcSpanAnnA (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
ms })
  = [FreeVars] -> FreeVars
plusFVs ((GenLocated
   SrcSpanAnnA (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
 -> FreeVars)
-> [GenLocated
      SrcSpanAnnA (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
-> [FreeVars]
forall a b. (a -> b) -> [a] -> [b]
map GenLocated
  SrcSpanAnnA (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> FreeVars
forall {l}.
GenLocated l (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> FreeVars
do_one [GenLocated
   SrcSpanAnnA (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
ms)
 where
    do_one :: GenLocated l (Match GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> FreeVars
do_one (L l
_ (Match { m_grhss :: forall p body. Match p body -> GRHSs p body
m_grhss = GRHSs GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn))
grhss })) = GRHSs GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesGRHSs GRHSs GhcRn (LHsCmd GhcRn)
GRHSs GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn))
grhss

-------------------------------------------------
-- gaw 2004
methodNamesGRHSs :: GRHSs GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesGRHSs :: GRHSs GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesGRHSs (GRHSs XCGRHSs GhcRn (LHsCmd GhcRn)
_ [LGRHS GhcRn (LHsCmd GhcRn)]
grhss HsLocalBinds GhcRn
_) = [FreeVars] -> FreeVars
plusFVs ((LocatedAn
   NoEpAnns (GRHS GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
 -> FreeVars)
-> [LocatedAn
      NoEpAnns (GRHS GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
-> [FreeVars]
forall a b. (a -> b) -> [a] -> [b]
map LocatedAn NoEpAnns (GRHS GhcRn (LHsCmd GhcRn)) -> FreeVars
LocatedAn
  NoEpAnns (GRHS GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> FreeVars
methodNamesGRHS [LGRHS GhcRn (LHsCmd GhcRn)]
[LocatedAn
   NoEpAnns (GRHS GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
grhss)

-------------------------------------------------

methodNamesGRHS :: LocatedAn NoEpAnns (GRHS GhcRn (LHsCmd GhcRn)) -> CmdNeeds
methodNamesGRHS :: LocatedAn NoEpAnns (GRHS GhcRn (LHsCmd GhcRn)) -> FreeVars
methodNamesGRHS (L EpAnn NoEpAnns
_ (GRHS XCGRHS GhcRn (LHsCmd GhcRn)
_ [ExprLStmt GhcRn]
_ LHsCmd GhcRn
rhs)) = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
rhs

---------------------------------------------------
methodNamesStmts :: [LStmtLR GhcRn GhcRn (LHsCmd GhcRn)] -> FreeVars
methodNamesStmts :: [CmdLStmt GhcRn] -> FreeVars
methodNamesStmts [CmdLStmt GhcRn]
stmts = [FreeVars] -> FreeVars
plusFVs ((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
 -> FreeVars)
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
-> [FreeVars]
forall a b. (a -> b) -> [a] -> [b]
map CmdLStmt GhcRn -> FreeVars
GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> FreeVars
methodNamesLStmt [CmdLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
stmts)

---------------------------------------------------
methodNamesLStmt :: LStmtLR GhcRn GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesLStmt :: CmdLStmt GhcRn -> FreeVars
methodNamesLStmt = StmtLR GhcRn GhcRn (LHsCmd GhcRn) -> FreeVars
StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn))
-> FreeVars
methodNamesStmt (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn))
 -> FreeVars)
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
    -> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> FreeVars
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn))
forall l e. GenLocated l e -> e
unLoc

methodNamesStmt :: StmtLR GhcRn GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesStmt :: StmtLR GhcRn GhcRn (LHsCmd GhcRn) -> FreeVars
methodNamesStmt (LastStmt XLastStmt GhcRn GhcRn (LHsCmd GhcRn)
_ LHsCmd GhcRn
cmd Maybe Bool
_ SyntaxExpr GhcRn
_)           = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
cmd
methodNamesStmt (BodyStmt XBodyStmt GhcRn GhcRn (LHsCmd GhcRn)
_ LHsCmd GhcRn
cmd SyntaxExpr GhcRn
_ SyntaxExpr GhcRn
_)           = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
cmd
methodNamesStmt (BindStmt XBindStmt GhcRn GhcRn (LHsCmd GhcRn)
_ LPat GhcRn
_ LHsCmd GhcRn
cmd)             = LHsCmd GhcRn -> FreeVars
methodNamesLCmd LHsCmd GhcRn
cmd
methodNamesStmt (RecStmt { recS_stmts :: forall idL idR body.
StmtLR idL idR body -> XRec idR [LStmtLR idL idR body]
recS_stmts = L SrcSpanAnnL
_ [GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
stmts }) =
  [CmdLStmt GhcRn] -> FreeVars
methodNamesStmts [CmdLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsCmd GhcRn)))]
stmts FreeVars -> Name -> FreeVars
`addOneFV` Name
loopAName
methodNamesStmt (LetStmt {})                   = FreeVars
emptyFVs
methodNamesStmt (ParStmt {})                   = FreeVars
emptyFVs
methodNamesStmt (TransStmt {})                 = FreeVars
emptyFVs
methodNamesStmt ApplicativeStmt{}              = FreeVars
emptyFVs
   -- ParStmt and TransStmt can't occur in commands, but it's not
   -- convenient to error here so we just do what's convenient

{-
************************************************************************
*                                                                      *
        Arithmetic sequences
*                                                                      *
************************************************************************
-}

rnArithSeq :: ArithSeqInfo GhcPs -> RnM (ArithSeqInfo GhcRn, FreeVars)
rnArithSeq :: ArithSeqInfo GhcPs -> RnM (ArithSeqInfo GhcRn, FreeVars)
rnArithSeq (From LHsExpr GhcPs
expr)
 = do { (expr', fvExpr) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr
      ; return (From expr', fvExpr) }

rnArithSeq (FromThen LHsExpr GhcPs
expr1 LHsExpr GhcPs
expr2)
 = do { (expr1', fvExpr1) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr1
      ; (expr2', fvExpr2) <- rnLExpr expr2
      ; return (FromThen expr1' expr2', fvExpr1 `plusFV` fvExpr2) }

rnArithSeq (FromTo LHsExpr GhcPs
expr1 LHsExpr GhcPs
expr2)
 = do { (expr1', fvExpr1) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr1
      ; (expr2', fvExpr2) <- rnLExpr expr2
      ; return (FromTo expr1' expr2', fvExpr1 `plusFV` fvExpr2) }

rnArithSeq (FromThenTo LHsExpr GhcPs
expr1 LHsExpr GhcPs
expr2 LHsExpr GhcPs
expr3)
 = do { (expr1', fvExpr1) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
expr1
      ; (expr2', fvExpr2) <- rnLExpr expr2
      ; (expr3', fvExpr3) <- rnLExpr expr3
      ; return (FromThenTo expr1' expr2' expr3',
                plusFVs [fvExpr1, fvExpr2, fvExpr3]) }

{-
************************************************************************
*                                                                      *
\subsubsection{@Stmt@s: in @do@ expressions}
*                                                                      *
************************************************************************
-}

{-
Note [Deterministic ApplicativeDo and RecursiveDo desugaring]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Both ApplicativeDo and RecursiveDo need to create tuples not
present in the source text.

For ApplicativeDo we create:

  (a,b,c) <- (\c b a -> (a,b,c)) <$>

For RecursiveDo we create:

  mfix (\ ~(a,b,c) -> do ...; return (a',b',c'))

The order of the components in those tuples needs to be stable
across recompilations, otherwise they can get optimized differently
and we end up with incompatible binaries.
To get a stable order we use nameSetElemsStable.
See Note [Deterministic UniqFM] to learn more about nondeterminism.
-}

type AnnoBody body
  = ( Outputable (body GhcPs)
    )

-- | Rename some Stmts
rnStmts :: AnnoBody body
        => HsStmtContextRn
        -> (body GhcPs -> RnM (body GhcRn, FreeVars))
           -- ^ How to rename the body of each statement (e.g. rnLExpr)
        -> [LStmt GhcPs (LocatedA (body GhcPs))]
           -- ^ Statements
        -> ([Name] -> RnM (thing, FreeVars))
           -- ^ if these statements scope over something, this renames it
           -- and returns the result.
        -> RnM (([LStmt GhcRn (LocatedA (body GhcRn))], thing), FreeVars)
rnStmts :: forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM (([LStmt GhcRn (LocatedA (body GhcRn))], thing), FreeVars)
rnStmts HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [LStmt GhcPs (LocatedA (body GhcPs))]
stmts [Name] -> RnM (thing, FreeVars)
thing_inside
 = do { ((stmts', thing), fvs) <- HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmtsWithFreeVars HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [LStmt GhcPs (LocatedA (body GhcPs))]
stmts [Name] -> RnM (thing, FreeVars)
thing_inside
      ; return ((map fst stmts', thing), fvs) }

-- | maybe rearrange statements according to the ApplicativeDo transformation
postProcessStmtsForApplicativeDo
  :: HsDoFlavour
  -> [(ExprLStmt GhcRn, FreeVars)]
  -> RnM ([ExprLStmt GhcRn], FreeVars)
postProcessStmtsForApplicativeDo :: HsDoFlavour
-> [(ExprLStmt GhcRn, FreeVars)]
-> RnM ([ExprLStmt GhcRn], FreeVars)
postProcessStmtsForApplicativeDo HsDoFlavour
ctxt [(ExprLStmt GhcRn, FreeVars)]
stmts
  = do {
       -- rearrange the statements using ApplicativeStmt if
       -- -XApplicativeDo is on.  Also strip out the FreeVars attached
       -- to each Stmt body.
         ado_is_on <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.ApplicativeDo
       ; let is_do_expr | DoExpr{} <- HsDoFlavour
ctxt = Bool
True
                        | Bool
otherwise = Bool
False
       -- don't apply the transformation inside TH brackets, because
       -- GHC.HsToCore.Quote does not handle ApplicativeDo.
       ; in_th_bracket <- isBrackStage <$> getStage
       ; if ado_is_on && is_do_expr && not in_th_bracket
            then do { traceRn "ppsfa" (ppr stmts)
                    ; rearrangeForApplicativeDo ctxt stmts }
            else noPostProcessStmts (HsDoStmt ctxt) stmts }

-- | strip the FreeVars annotations from statements
noPostProcessStmts
  :: HsStmtContextRn
  -> [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
  -> RnM ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
noPostProcessStmts :: forall (body :: * -> *).
HsStmtContextRn
-> [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
-> RnM ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
noPostProcessStmts HsStmtContextRn
_ [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
stmts = ([GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn)))],
 FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn)))],
      FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (((GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
  FreeVars)
 -> GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
     FreeVars)]
-> [GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn)))]
forall a b. (a -> b) -> [a] -> [b]
map (GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
 FreeVars)
-> GenLocated
     SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn)))
forall a b. (a, b) -> a
fst [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
  FreeVars)]
stmts, FreeVars
emptyNameSet)


rnStmtsWithFreeVars :: AnnoBody body
        => HsStmtContextRn
        -> ((body GhcPs) -> RnM ((body GhcRn), FreeVars))
        -> [LStmt GhcPs (LocatedA (body GhcPs))]
        -> ([Name] -> RnM (thing, FreeVars))
        -> RnM ( ([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing)
               , FreeVars)
-- Each Stmt body is annotated with its FreeVars, so that
-- we can rearrange statements for ApplicativeDo.
--
-- Variables bound by the Stmts, and mentioned in thing_inside,
-- do not appear in the result FreeVars

rnStmtsWithFreeVars :: forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmtsWithFreeVars HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
_ [] [Name] -> RnM (thing, FreeVars)
thing_inside
  = do { HsStmtContextRn -> IOEnv (Env TcGblEnv TcLclEnv) ()
checkEmptyStmts HsStmtContextRn
ctxt
       ; (thing, fvs) <- [Name] -> RnM (thing, FreeVars)
thing_inside []
       ; return (([], thing), fvs) }

rnStmtsWithFreeVars mDoExpr :: HsStmtContextRn
mDoExpr@(HsDoStmt MDoExpr{}) body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody ([LStmt GhcPs (LocatedA (body GhcPs))]
-> Maybe
     (NonEmpty
        (GenLocated
           SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))))
[GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
-> Maybe
     (NonEmpty
        (GenLocated
           SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))))
forall a. [a] -> Maybe (NonEmpty a)
nonEmpty -> Just NonEmpty
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
stmts) [Name] -> RnM (thing, FreeVars)
thing_inside    -- Deal with mdo
  = -- Behave like do { rec { ...all but last... }; last }
    do { ((stmts1, (stmts2, thing)), fvs)
           <- HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> LStmt GhcPs (LocatedA (body GhcPs))
-> ([Name]
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (([(GenLocated
               SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
             FreeVars)],
           thing),
          FreeVars))
-> RnM
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> LStmt GhcPs (LocatedA (body GhcPs))
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmt HsStmtContextRn
mDoExpr body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
-> GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
forall e a. HasAnnotation e => a -> GenLocated e a
noLocA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
 -> GenLocated
      SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
-> StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
-> GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
forall a b. (a -> b) -> a -> b
$ AnnList
-> LocatedL [LStmt GhcPs (LocatedA (body GhcPs))]
-> StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
forall (idL :: Pass) bodyR.
(Anno
   [GenLocated
      (Anno (StmtLR (GhcPass idL) GhcPs bodyR))
      (StmtLR (GhcPass idL) GhcPs bodyR)]
 ~ SrcSpanAnnL) =>
AnnList
-> LocatedL [LStmtLR (GhcPass idL) GhcPs bodyR]
-> StmtLR (GhcPass idL) GhcPs bodyR
mkRecStmt AnnList
forall a. NoAnn a => a
noAnn ([GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
-> GenLocated
     SrcSpanAnnL
     [GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
forall e a. HasAnnotation e => a -> GenLocated e a
noLocA (NonEmpty
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
-> [GenLocated
      SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
forall a. NonEmpty a -> [a]
NE.init NonEmpty
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
stmts))) (([Name]
  -> IOEnv
       (Env TcGblEnv TcLclEnv)
       (([(GenLocated
             SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
           FreeVars)],
         thing),
        FreeVars))
 -> RnM
      (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        ([(GenLocated
             SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
           FreeVars)],
         thing)),
       FreeVars))
-> ([Name]
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (([(GenLocated
               SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
             FreeVars)],
           thing),
          FreeVars))
-> RnM
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
forall a b. (a -> b) -> a -> b
$ \ [Name]
_ ->
              do { last_stmt' <- HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
checkLastStmt HsStmtContextRn
mDoExpr (NonEmpty
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
-> GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
forall a. NonEmpty a -> a
NE.last NonEmpty
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
stmts)
                 ; rnStmt mDoExpr rnBody last_stmt' thing_inside }
        ; return (((stmts1 ++ stmts2), thing), fvs) }

rnStmtsWithFreeVars HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody (lstmt :: LStmt GhcPs (LocatedA (body GhcPs))
lstmt@(L SrcSpanAnnA
loc StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
_) : [LStmt GhcPs (LocatedA (body GhcPs))]
lstmts) [Name] -> RnM (thing, FreeVars)
thing_inside
  | [GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
-> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [LStmt GhcPs (LocatedA (body GhcPs))]
[GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
lstmts
  = SrcSpanAnnA
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall ann a. EpAnn ann -> TcRn a -> TcRn a
setSrcSpanA SrcSpanAnnA
loc (IOEnv
   (Env TcGblEnv TcLclEnv)
   (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
       FreeVars)],
     thing),
    FreeVars)
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing),
       FreeVars))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall a b. (a -> b) -> a -> b
$
    do { lstmt' <- HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
checkLastStmt HsStmtContextRn
ctxt LStmt GhcPs (LocatedA (body GhcPs))
lstmt
       ; rnStmt ctxt rnBody lstmt' thing_inside }

  | Bool
otherwise
  = do { ((stmts1, (stmts2, thing)), fvs)
            <- SrcSpanAnnA
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(GenLocated
           SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(GenLocated
           SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
forall ann a. EpAnn ann -> TcRn a -> TcRn a
setSrcSpanA SrcSpanAnnA
loc                  (IOEnv
   (Env TcGblEnv TcLclEnv)
   (([(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
       FreeVars)],
     ([(GenLocated
          SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
        FreeVars)],
      thing)),
    FreeVars)
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        ([(GenLocated
             SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
           FreeVars)],
         thing)),
       FreeVars))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(GenLocated
           SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(GenLocated
           SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
forall a b. (a -> b) -> a -> b
$
               do { HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> IOEnv (Env TcGblEnv TcLclEnv) ()
checkStmt HsStmtContextRn
ctxt LStmt GhcPs (LocatedA (body GhcPs))
lstmt
                  ; HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> LStmt GhcPs (LocatedA (body GhcPs))
-> ([Name]
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (([(GenLocated
               SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
             FreeVars)],
           thing),
          FreeVars))
-> RnM
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> LStmt GhcPs (LocatedA (body GhcPs))
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody LStmt GhcPs (LocatedA (body GhcPs))
lstmt (([Name]
  -> IOEnv
       (Env TcGblEnv TcLclEnv)
       (([(GenLocated
             SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
           FreeVars)],
         thing),
        FreeVars))
 -> RnM
      (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        ([(GenLocated
             SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
           FreeVars)],
         thing)),
       FreeVars))
-> ([Name]
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (([(GenLocated
               SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
             FreeVars)],
           thing),
          FreeVars))
-> RnM
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       ([(GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing)),
      FreeVars)
forall a b. (a -> b) -> a -> b
$ \ [Name]
bndrs1 ->
                    HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmtsWithFreeVars HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [LStmt GhcPs (LocatedA (body GhcPs))]
lstmts  (([Name] -> RnM (thing, FreeVars))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing),
       FreeVars))
-> ([Name] -> RnM (thing, FreeVars))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall a b. (a -> b) -> a -> b
$ \ [Name]
bndrs2 ->
                    [Name] -> RnM (thing, FreeVars)
thing_inside ([Name]
bndrs1 [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++ [Name]
bndrs2) }
        ; return (((stmts1 ++ stmts2), thing), fvs) }

----------------------

{-
Note [Failing pattern matches in Stmts]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Many things desugar to HsStmts including monadic things like `do` and `mdo`
statements, pattern guards, and list comprehensions (see 'HsStmtContext' for an
exhaustive list). How we deal with pattern match failure is context-dependent.

 * In the case of list comprehensions and pattern guards we don't need any
   'fail' function; the desugarer ignores the fail function of 'BindStmt'
   entirely. So, for list comprehensions, the fail function is set to 'Nothing'
   for clarity.

* In the case of monadic contexts (e.g. monad comprehensions, do, and mdo
   expressions) we want pattern match failure to be desugared to the
   'fail' function (from MonadFail type class).

At one point we failed to make this distinction, leading to #11216.
-}

rnStmt :: AnnoBody body
       => HsStmtContextRn
       -> (body GhcPs -> RnM (body GhcRn, FreeVars))
          -- ^ How to rename the body of the statement
       -> LStmt GhcPs (LocatedA (body GhcPs))
          -- ^ The statement
       -> ([Name] -> RnM (thing, FreeVars))
          -- ^ Rename the stuff that this statement scopes over
       -> RnM ( ([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing)
              , FreeVars)
-- Variables bound by the Stmt, and mentioned in thing_inside,
-- do not appear in the result FreeVars

rnStmt :: forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> LStmt GhcPs (LocatedA (body GhcPs))
-> ([Name] -> RnM (thing, FreeVars))
-> RnM
     (([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)], thing),
      FreeVars)
rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody (L SrcSpanAnnA
loc (LastStmt XLastStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ (L SrcSpanAnnA
lb body GhcPs
body) Maybe Bool
noret SyntaxExpr GhcPs
_)) [Name] -> RnM (thing, FreeVars)
thing_inside
  = do  { (body', fv_expr) <- body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody body GhcPs
body
        ; (ret_op, fvs1) <- if isMonadCompContext ctxt
                            then lookupStmtName ctxt returnMName
                            else return (noSyntaxExpr, emptyFVs)
                            -- The 'return' in a LastStmt is used only
                            -- for MonadComp; and we don't want to report
                            -- "not in scope: return" in other cases
                            -- #15607

        ; (thing,  fvs3) <- thing_inside []
        ; return (([(L loc (LastStmt noExtField (L lb body') noret ret_op), fv_expr)]
                  , thing), fv_expr `plusFV` fvs1 `plusFV` fvs3) }

rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody (L SrcSpanAnnA
loc (BodyStmt XBodyStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ (L SrcSpanAnnA
lb body GhcPs
body) SyntaxExpr GhcPs
_ SyntaxExpr GhcPs
_)) [Name] -> RnM (thing, FreeVars)
thing_inside
  = do  { (body', fv_expr) <- body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody body GhcPs
body
        ; (then_op, fvs1)  <- lookupQualifiedDoStmtName ctxt thenMName

        ; (guard_op, fvs2) <- if isComprehensionContext ctxt
                              then lookupStmtName ctxt guardMName
                              else return (noSyntaxExpr, emptyFVs)
                              -- Only list/monad comprehensions use 'guard'
                              -- Also for sub-stmts of same eg [ e | x<-xs, gd | blah ]
                              -- Here "gd" is a guard

        ; (thing, fvs3)    <- thing_inside []
        ; return ( ([(L loc (BodyStmt noExtField (L lb body') then_op guard_op), fv_expr)]
                  , thing), fv_expr `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) }

rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody (L SrcSpanAnnA
loc (BindStmt XBindStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ LPat GhcPs
pat (L SrcSpanAnnA
lb body GhcPs
body))) [Name] -> RnM (thing, FreeVars)
thing_inside
  = do  { (body', fv_expr) <- body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody body GhcPs
body
                -- The binders do not scope over the expression
        ; (bind_op, fvs1) <- lookupQualifiedDoStmtName ctxt bindMName

        ; (fail_op, fvs2) <- monadFailOp pat ctxt

        ; rnPat (StmtCtxt ctxt) pat $ \ LPat GhcRn
pat' -> do
        { (thing, fvs3) <- [Name] -> RnM (thing, FreeVars)
thing_inside (CollectFlag GhcRn -> LPat GhcRn -> [IdP GhcRn]
forall p. CollectPass p => CollectFlag p -> LPat p -> [IdP p]
collectPatBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders LPat GhcRn
pat')
        ; let xbsrn = XBindStmtRn { xbsrn_bindOp :: SyntaxExpr GhcRn
xbsrn_bindOp = SyntaxExpr GhcRn
SyntaxExprRn
bind_op, xbsrn_failOp :: Maybe (SyntaxExpr GhcRn)
xbsrn_failOp = Maybe (SyntaxExpr GhcRn)
Maybe SyntaxExprRn
fail_op }
        ; return (( [( L loc (BindStmt xbsrn pat' (L lb body')), fv_expr )]
                  , thing),
                  fv_expr `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) }}
       -- fv_expr shouldn't really be filtered by the rnPatsAndThen
        -- but it does not matter because the names are unique

rnStmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ (L SrcSpanAnnA
loc (LetStmt XLetStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ HsLocalBinds GhcPs
binds)) [Name] -> RnM (thing, FreeVars)
thing_inside
  =     HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn
    -> FreeVars
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
             FreeVars)],
           thing),
          FreeVars))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall result.
HsLocalBinds GhcPs
-> (HsLocalBinds GhcRn -> FreeVars -> RnM (result, FreeVars))
-> RnM (result, FreeVars)
rnLocalBindsAndThen HsLocalBinds GhcPs
binds ((HsLocalBinds GhcRn
  -> FreeVars
  -> IOEnv
       (Env TcGblEnv TcLclEnv)
       (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
           FreeVars)],
         thing),
        FreeVars))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
          FreeVars)],
        thing),
       FreeVars))
-> (HsLocalBinds GhcRn
    -> FreeVars
    -> IOEnv
         (Env TcGblEnv TcLclEnv)
         (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
             FreeVars)],
           thing),
          FreeVars))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall a b. (a -> b) -> a -> b
$ \HsLocalBinds GhcRn
binds' FreeVars
bind_fvs -> do
        { (thing, fvs) <- [Name] -> RnM (thing, FreeVars)
thing_inside (CollectFlag GhcRn -> HsLocalBinds GhcRn -> [IdP GhcRn]
forall (idL :: Pass) (idR :: Pass).
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> HsLocalBindsLR (GhcPass idL) (GhcPass idR)
-> [IdP (GhcPass idL)]
collectLocalBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders HsLocalBinds GhcRn
binds')
        ; return ( ([(L loc (LetStmt noAnn binds'), bind_fvs)], thing)
                 , fvs) }

rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody (L SrcSpanAnnA
loc (RecStmt { recS_stmts :: forall idL idR body.
StmtLR idL idR body -> XRec idR [LStmtLR idL idR body]
recS_stmts = L SrcSpanAnnL
_ [GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
rec_stmts })) [Name] -> RnM (thing, FreeVars)
thing_inside
  = do  { (return_op, fvs1)  <- HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupQualifiedDoStmtName HsStmtContextRn
ctxt Name
returnMName
        ; (mfix_op,   fvs2)  <- lookupQualifiedDoStmtName ctxt mfixName
        ; (bind_op,   fvs3)  <- lookupQualifiedDoStmtName ctxt bindMName
        ; let empty_rec_stmt = (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))
forall bodyR.
(Anno
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn bodyR)) (StmtLR GhcRn GhcRn bodyR)]
 ~ SrcSpanAnnL) =>
StmtLR GhcRn GhcRn bodyR
forall {body :: * -> *}. StmtLR GhcRn GhcRn (LocatedA (body GhcRn))
emptyRecStmtName :: StmtLR GhcRn GhcRn (LocatedA (body GhcRn)))
                                { recS_ret_fn  = return_op
                                , recS_mfix_fn = mfix_op
                                , recS_bind_fn = bind_op }

        -- Step1: Bring all the binders of the mdo into scope
        -- (Remember that this also removes the binders from the
        -- finally-returned free-vars.)
        -- And rename each individual stmt, making a
        -- singleton segment.  At this stage the FwdRefs field
        -- isn't finished: it's empty for all except a BindStmt
        -- for which it's the fwd refs within the bind itself
        -- (This set may not be empty, because we're in a recursive
        -- context.)
        ; rnRecStmtsAndThen ctxt rnBody rec_stmts   $ \ [Segment (XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
segs -> do
        { let bndrs :: [Name]
bndrs = FreeVars -> [Name]
nameSetElemsStable (FreeVars -> [Name]) -> FreeVars -> [Name]
forall a b. (a -> b) -> a -> b
$
                        ((FreeVars, FreeVars, FreeVars,
  GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))
 -> FreeVars -> FreeVars)
-> FreeVars
-> [(FreeVars, FreeVars, FreeVars,
     GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
-> FreeVars
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr (FreeVars -> FreeVars -> FreeVars
unionNameSet (FreeVars -> FreeVars -> FreeVars)
-> ((FreeVars, FreeVars, FreeVars,
     GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))
    -> FreeVars)
-> (FreeVars, FreeVars, FreeVars,
    GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))
-> FreeVars
-> FreeVars
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (\(FreeVars
ds,FreeVars
_,FreeVars
_,GenLocated SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn)))
_) -> FreeVars
ds))
                              FreeVars
emptyNameSet
                              [Segment (XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
[(FreeVars, FreeVars, FreeVars,
  GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
segs
          -- See Note [Deterministic ApplicativeDo and RecursiveDo desugaring]
        ; (thing, fvs_later) <- [Name] -> RnM (thing, FreeVars)
thing_inside [Name]
bndrs
        -- In interactive mode, all variables could be used later. So we pass whether
        -- we are in GHCi along to segmentRecStmts. See Note [What is "used later" in a rec stmt]
        ; is_interactive <- isInteractiveModule . tcg_mod <$> getGblEnv
        ; let
             (rec_stmts', fvs) = segmentRecStmts (locA loc) ctxt empty_rec_stmt segs (fvs_later, is_interactive)
        -- We aren't going to try to group RecStmts with
        -- ApplicativeDo, so attaching empty FVs is fine.
        ; return ( ((zip rec_stmts' (repeat emptyNameSet)), thing)
                 , fvs `plusFV` fvs1 `plusFV` fvs2 `plusFV` fvs3) } }

rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
_ (L SrcSpanAnnA
loc (ParStmt XParStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ [ParStmtBlock GhcPs GhcPs]
segs HsExpr GhcPs
_ SyntaxExpr GhcPs
_)) [Name] -> RnM (thing, FreeVars)
thing_inside
  = do  { (mzip_op, fvs1)   <- HsStmtContextRn -> Name -> TcM (HsExpr GhcRn, FreeVars)
lookupStmtNamePoly HsStmtContextRn
ctxt Name
mzipName
        ; (bind_op, fvs2)   <- lookupStmtName ctxt bindMName
        ; (return_op, fvs3) <- lookupStmtName ctxt returnMName
        ; ((segs', thing), fvs4) <- rnParallelStmts (ParStmtCtxt ctxt) return_op segs thing_inside
        ; return (([(L loc (ParStmt noExtField segs' mzip_op bind_op), fvs4)], thing)
                 , fvs1 `plusFV` fvs2 `plusFV` fvs3 `plusFV` fvs4) }

rnStmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
_ (L SrcSpanAnnA
loc (TransStmt { trS_stmts :: forall idL idR body. StmtLR idL idR body -> [ExprLStmt idL]
trS_stmts = [ExprLStmt GhcPs]
stmts, trS_by :: forall idL idR body. StmtLR idL idR body -> Maybe (LHsExpr idR)
trS_by = Maybe (LHsExpr GhcPs)
by, trS_form :: forall idL idR body. StmtLR idL idR body -> TransForm
trS_form = TransForm
form
                              , trS_using :: forall idL idR body. StmtLR idL idR body -> LHsExpr idR
trS_using = LHsExpr GhcPs
using })) [Name] -> RnM (thing, FreeVars)
thing_inside
  = do { -- Rename the 'using' expression in the context before the transform is begun
         (using', fvs1) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
using

         -- Rename the stmts and the 'by' expression
         -- Keep track of the variables mentioned in the 'by' expression
       ; ((stmts', (by', used_bndrs, thing)), fvs2)
             <- rnStmts (TransStmtCtxt ctxt) rnExpr stmts $ \ [Name]
bndrs ->
                do { (by',   fvs_by) <- (GenLocated SrcSpanAnnA (HsExpr GhcPs)
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars))
-> Maybe (GenLocated SrcSpanAnnA (HsExpr GhcPs))
-> RnM (Maybe (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)
forall a b.
(a -> RnM (b, FreeVars)) -> Maybe a -> RnM (Maybe b, FreeVars)
mapMaybeFvRn LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
GenLocated SrcSpanAnnA (HsExpr GhcPs)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated SrcSpanAnnA (HsExpr GhcRn), FreeVars)
rnLExpr Maybe (LHsExpr GhcPs)
Maybe (GenLocated SrcSpanAnnA (HsExpr GhcPs))
by
                   ; (thing, fvs_thing) <- thing_inside bndrs
                   ; let fvs = FreeVars
fvs_by FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs_thing
                         used_bndrs = (Name -> Bool) -> [Name] -> [Name]
forall a. (a -> Bool) -> [a] -> [a]
filter (Name -> FreeVars -> Bool
`elemNameSet` FreeVars
fvs) [Name]
bndrs
                         -- The paper (Fig 5) has a bug here; we must treat any free variable
                         -- of the "thing inside", **or of the by-expression**, as used
                   ; return ((by', used_bndrs, thing), fvs) }

       -- Lookup `return`, `(>>=)` and `liftM` for monad comprehensions
       ; (return_op, fvs3) <- lookupStmtName ctxt returnMName
       ; (bind_op,   fvs4) <- lookupStmtName ctxt bindMName
       ; (fmap_op,   fvs5) <- case form of
                                TransForm
ThenForm -> (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcRn
forall (p :: Pass). HsExpr (GhcPass p)
noExpr, FreeVars
emptyFVs)
                                TransForm
_        -> HsStmtContextRn -> Name -> TcM (HsExpr GhcRn, FreeVars)
lookupStmtNamePoly HsStmtContextRn
ctxt Name
fmapName

       ; let all_fvs  = FreeVars
fvs1 FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs2 FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs3
                             FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs4 FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs5
             bndr_map = [Name]
used_bndrs [Name] -> [Name] -> [(Name, Name)]
forall a b. [a] -> [b] -> [(a, b)]
`zip` [Name]
used_bndrs
             -- See Note [TransStmt binder map] in GHC.Hs.Expr

       ; traceRn "rnStmt: implicitly rebound these used binders:" (ppr bndr_map)
       ; return (([(L loc (TransStmt { trS_ext = noExtField
                                    , trS_stmts = stmts', trS_bndrs = bndr_map
                                    , trS_by = by', trS_using = using', trS_form = form
                                    , trS_ret = return_op, trS_bind = bind_op
                                    , trS_fmap = fmap_op }), fvs2)], thing), all_fvs) }

rnStmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ (L SrcSpanAnnA
_ ApplicativeStmt{}) [Name] -> RnM (thing, FreeVars)
_ =
  String
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (([(GenLocated
           SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
         FreeVars)],
       thing),
      FreeVars)
forall a. HasCallStack => String -> a
panic String
"rnStmt: ApplicativeStmt"

rnParallelStmts :: forall thing. HsStmtContextRn
                -> SyntaxExpr GhcRn
                -> [ParStmtBlock GhcPs GhcPs]
                -> ([Name] -> RnM (thing, FreeVars))
                -> RnM (([ParStmtBlock GhcRn GhcRn], thing), FreeVars)
-- Note [Renaming parallel Stmts]
rnParallelStmts :: forall thing.
HsStmtContextRn
-> SyntaxExpr GhcRn
-> [ParStmtBlock GhcPs GhcPs]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM (([ParStmtBlock GhcRn GhcRn], thing), FreeVars)
rnParallelStmts HsStmtContextRn
ctxt SyntaxExpr GhcRn
return_op [ParStmtBlock GhcPs GhcPs]
segs [Name] -> RnM (thing, FreeVars)
thing_inside
  = do { orig_lcl_env <- RnM LocalRdrEnv
getLocalRdrEnv
       ; rn_segs orig_lcl_env [] segs }
  where
    rn_segs :: LocalRdrEnv
            -> [Name] -> [ParStmtBlock GhcPs GhcPs]
            -> RnM (([ParStmtBlock GhcRn GhcRn], thing), FreeVars)
    rn_segs :: LocalRdrEnv
-> [Name]
-> [ParStmtBlock GhcPs GhcPs]
-> RnM (([ParStmtBlock GhcRn GhcRn], thing), FreeVars)
rn_segs LocalRdrEnv
_ [Name]
bndrs_so_far []
      = do { let ([Name]
bndrs', [NonEmpty Name]
dups) = (Name -> OccName) -> [Name] -> ([Name], [NonEmpty Name])
forall b a. Ord b => (a -> b) -> [a] -> ([a], [NonEmpty a])
removeDupsOn Name -> OccName
nameOccName [Name]
bndrs_so_far
           ; (NonEmpty Name -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> [NonEmpty Name] -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ NonEmpty Name -> IOEnv (Env TcGblEnv TcLclEnv) ()
dupErr [NonEmpty Name]
dups
           ; (thing, fvs) <- [Name] -> RnM (thing, FreeVars) -> RnM (thing, FreeVars)
forall a. [Name] -> RnM a -> RnM a
bindLocalNames [Name]
bndrs' ([Name] -> RnM (thing, FreeVars)
thing_inside [Name]
bndrs')
           ; return (([], thing), fvs) }

    rn_segs LocalRdrEnv
env [Name]
bndrs_so_far (ParStmtBlock XParStmtBlock GhcPs GhcPs
x [ExprLStmt GhcPs]
stmts [IdP GhcPs]
_ SyntaxExpr GhcPs
_ : [ParStmtBlock GhcPs GhcPs]
segs)
      = do { ((stmts', (used_bndrs, segs', thing)), fvs)
                    <- HsStmtContextRn
-> (HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars))
-> [LStmt GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))]
-> ([Name]
    -> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars))
-> RnM
     (([LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))],
       ([Name], [ParStmtBlock GhcRn GhcRn], thing)),
      FreeVars)
forall (body :: * -> *) thing.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Name] -> RnM (thing, FreeVars))
-> RnM (([LStmt GhcRn (LocatedA (body GhcRn))], thing), FreeVars)
rnStmts HsStmtContextRn
ctxt HsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnExpr [ExprLStmt GhcPs]
[LStmt GhcPs (GenLocated SrcSpanAnnA (HsExpr GhcPs))]
stmts (([Name]
  -> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars))
 -> RnM
      (([LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))],
        ([Name], [ParStmtBlock GhcRn GhcRn], thing)),
       FreeVars))
-> ([Name]
    -> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars))
-> RnM
     (([LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))],
       ([Name], [ParStmtBlock GhcRn GhcRn], thing)),
      FreeVars)
forall a b. (a -> b) -> a -> b
$ \ [Name]
bndrs ->
                       LocalRdrEnv
-> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars)
-> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars)
forall a. LocalRdrEnv -> RnM a -> RnM a
setLocalRdrEnv LocalRdrEnv
env       (RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars)
 -> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars))
-> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars)
-> RnM (([Name], [ParStmtBlock GhcRn GhcRn], thing), FreeVars)
forall a b. (a -> b) -> a -> b
$ do
                       { ((segs', thing), fvs) <- LocalRdrEnv
-> [Name]
-> [ParStmtBlock GhcPs GhcPs]
-> RnM (([ParStmtBlock GhcRn GhcRn], thing), FreeVars)
rn_segs LocalRdrEnv
env ([Name]
bndrs [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++ [Name]
bndrs_so_far) [ParStmtBlock GhcPs GhcPs]
segs
                       ; let used_bndrs = (Name -> Bool) -> [Name] -> [Name]
forall a. (a -> Bool) -> [a] -> [a]
filter (Name -> FreeVars -> Bool
`elemNameSet` FreeVars
fvs) [Name]
bndrs
                       ; return ((used_bndrs, segs', thing), fvs) }

           ; let seg' = XParStmtBlock GhcRn GhcRn
-> [ExprLStmt GhcRn]
-> [IdP GhcRn]
-> SyntaxExpr GhcRn
-> ParStmtBlock GhcRn GhcRn
forall idL idR.
XParStmtBlock idL idR
-> [ExprLStmt idL]
-> [IdP idR]
-> SyntaxExpr idR
-> ParStmtBlock idL idR
ParStmtBlock XParStmtBlock GhcPs GhcPs
XParStmtBlock GhcRn GhcRn
x [ExprLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
stmts' [IdP GhcRn]
[Name]
used_bndrs SyntaxExpr GhcRn
return_op
           ; return ((seg':segs', thing), fvs) }

    dupErr :: NonEmpty Name -> IOEnv (Env TcGblEnv TcLclEnv) ()
dupErr NonEmpty Name
vs = TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$ Name -> TcRnMessage
TcRnListComprehensionDuplicateBinding (NonEmpty Name -> Name
forall a. NonEmpty a -> a
NE.head NonEmpty Name
vs)

lookupQualifiedDoStmtName :: HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
-- Like lookupStmtName, but respects QualifiedDo
lookupQualifiedDoStmtName :: HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupQualifiedDoStmtName HsStmtContextRn
ctxt Name
n
  = case HsStmtContext (GenLocated SrcSpanAnnN Name) -> Maybe ModuleName
forall fn. HsStmtContext fn -> Maybe ModuleName
qualifiedDoModuleName_maybe HsStmtContextRn
HsStmtContext (GenLocated SrcSpanAnnN Name)
ctxt of
      Maybe ModuleName
Nothing -> HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupStmtName HsStmtContextRn
ctxt Name
n
      Just ModuleName
modName ->
        (Name -> SyntaxExprRn)
-> (Name, FreeVars) -> (SyntaxExprRn, FreeVars)
forall b c d. (b -> c) -> (b, d) -> (c, d)
forall (a :: * -> * -> *) b c d.
Arrow a =>
a b c -> a (b, d) (c, d)
first (HsExpr GhcRn -> SyntaxExprRn
mkSyntaxExpr (HsExpr GhcRn -> SyntaxExprRn)
-> (Name -> HsExpr GhcRn) -> Name -> SyntaxExprRn
forall b c a. (b -> c) -> (a -> b) -> a -> c
. IdP GhcRn -> HsExpr GhcRn
Name -> HsExpr GhcRn
forall (p :: Pass) a.
IsSrcSpanAnn p a =>
IdP (GhcPass p) -> HsExpr (GhcPass p)
nl_HsVar) ((Name, FreeVars) -> (SyntaxExprRn, FreeVars))
-> RnM (Name, FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (SyntaxExprRn, FreeVars)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Name -> ModuleName -> RnM (Name, FreeVars)
lookupNameWithQualifier Name
n ModuleName
modName

lookupStmtName :: HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
-- Like lookupSyntax, but respects contexts
lookupStmtName :: HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupStmtName HsStmtContextRn
ctxt Name
n
  | HsStmtContextRn -> Bool
rebindableContext HsStmtContextRn
ctxt
  = Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupSyntax Name
n
  | Bool
otherwise
  = (SyntaxExprRn, FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (SyntaxExprRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (Name -> SyntaxExprRn
mkRnSyntaxExpr Name
n, FreeVars
emptyFVs)

lookupStmtNamePoly :: HsStmtContextRn -> Name -> RnM (HsExpr GhcRn, FreeVars)
lookupStmtNamePoly :: HsStmtContextRn -> Name -> TcM (HsExpr GhcRn, FreeVars)
lookupStmtNamePoly HsStmtContextRn
ctxt Name
name
  | HsStmtContextRn -> Bool
rebindableContext HsStmtContextRn
ctxt
  = do { rebindable_on <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.RebindableSyntax
       ; if rebindable_on
         then do { fm <- lookupOccRn (nameRdrName name)
                 ; return (HsVar noExtField (noLocA fm), unitFV fm) }
         else not_rebindable }
  | Bool
otherwise
  = TcM (HsExpr GhcRn, FreeVars)
not_rebindable
  where
    not_rebindable :: TcM (HsExpr GhcRn, FreeVars)
not_rebindable = (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (XVar GhcRn -> XRec GhcRn (IdP GhcRn) -> HsExpr GhcRn
forall p. XVar p -> LIdP p -> HsExpr p
HsVar XVar GhcRn
NoExtField
noExtField (Name -> GenLocated SrcSpanAnnN Name
forall e a. HasAnnotation e => a -> GenLocated e a
noLocA Name
name), FreeVars
emptyFVs)

-- | Is this a context where we respect RebindableSyntax?
-- but ListComp are never rebindable
-- Neither is ArrowExpr, which has its own desugarer in GHC.HsToCore.Arrows
rebindableContext :: HsStmtContextRn -> Bool
rebindableContext :: HsStmtContextRn -> Bool
rebindableContext HsStmtContextRn
ctxt = case HsStmtContextRn
ctxt of
  HsDoStmt HsDoFlavour
flavour -> HsDoFlavour -> Bool
rebindableDoStmtContext HsDoFlavour
flavour
  HsStmtContextRn
ArrowExpr -> Bool
False
  PatGuard {} -> Bool
False


  ParStmtCtxt   HsStmtContextRn
c -> HsStmtContextRn -> Bool
rebindableContext HsStmtContextRn
c     -- Look inside to
  TransStmtCtxt HsStmtContextRn
c -> HsStmtContextRn -> Bool
rebindableContext HsStmtContextRn
c     -- the parent context

rebindableDoStmtContext :: HsDoFlavour -> Bool
rebindableDoStmtContext :: HsDoFlavour -> Bool
rebindableDoStmtContext HsDoFlavour
flavour = case HsDoFlavour
flavour of
  HsDoFlavour
ListComp -> Bool
False
  DoExpr Maybe ModuleName
m -> Maybe ModuleName -> Bool
forall a. Maybe a -> Bool
isNothing Maybe ModuleName
m
  MDoExpr Maybe ModuleName
m -> Maybe ModuleName -> Bool
forall a. Maybe a -> Bool
isNothing Maybe ModuleName
m
  HsDoFlavour
MonadComp -> Bool
True
  HsDoFlavour
GhciStmtCtxt -> Bool
True   -- I suppose?

{-
Note [Renaming parallel Stmts]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Renaming parallel statements is painful.  Given, say
     [ a+c | a <- as, bs <- bss
           | c <- bs, a <- ds ]
Note that
  (a) In order to report "Defined but not used" about 'bs', we must
      rename each group of Stmts with a thing_inside whose FreeVars
      include at least {a,c}

  (b) We want to report that 'a' is illegally bound in both branches

  (c) The 'bs' in the second group must obviously not be captured by
      the binding in the first group

To satisfy (a) we nest the segments.
To satisfy (b) we check for duplicates just before thing_inside.
To satisfy (c) we reset the LocalRdrEnv each time.

************************************************************************
*                                                                      *
\subsubsection{mdo expressions}
*                                                                      *
************************************************************************
-}

type FwdRefs = NameSet
type Segment stmts = (Defs,
                      Uses,     -- May include defs
                      FwdRefs,  -- A subset of uses that are
                                --   (a) used before they are bound in this segment, or
                                --   (b) used here, and bound in subsequent segments
                      stmts)    -- Either Stmt or [Stmt]


-- wrapper that does both the left- and right-hand sides
rnRecStmtsAndThen :: AnnoBody body
                  => HsStmtContextRn
                  -> (body GhcPs -> RnM (body GhcRn, FreeVars))
                  -> [LStmt GhcPs (LocatedA (body GhcPs))]
                         -- assumes that the FreeVars returned includes
                         -- the FreeVars of the Segments
                  -> ([Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
                      -> RnM (a, FreeVars))
                  -> RnM (a, FreeVars)
rnRecStmtsAndThen :: forall (body :: * -> *) a.
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> ([Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
    -> RnM (a, FreeVars))
-> RnM (a, FreeVars)
rnRecStmtsAndThen HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [LStmt GhcPs (LocatedA (body GhcPs))]
s [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
-> RnM (a, FreeVars)
cont
  = do  { -- (A) Make the mini fixity env for all of the stmts
          fix_env <- [LFixitySig GhcPs] -> RnM MiniFixityEnv
makeMiniFixityEnv ([LStmt GhcPs (LocatedA (body GhcPs))] -> [LFixitySig GhcPs]
forall body. [LStmtLR GhcPs GhcPs body] -> [LFixitySig GhcPs]
collectRecStmtsFixities [LStmt GhcPs (LocatedA (body GhcPs))]
s)

          -- (B) Do the LHSes
        ; new_lhs_and_fv <- rn_rec_stmts_lhs fix_env s

          --    ...bring them and their fixities into scope
        ; let bound_names = CollectFlag GhcRn
-> [LStmtLR GhcRn GhcPs (LocatedA (body GhcPs))] -> [IdP GhcRn]
forall (idL :: Pass) (idR :: Pass) body.
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> [LStmtLR (GhcPass idL) (GhcPass idR) body]
-> [IdP (GhcPass idL)]
collectLStmtsBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders (((GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)
 -> GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))))
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
     FreeVars)]
-> [GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))]
forall a b. (a -> b) -> [a] -> [b]
map (GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> GenLocated
     SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))
forall a b. (a, b) -> a
fst [(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)]
new_lhs_and_fv)
              -- Fake uses of variables introduced implicitly (warning suppression, see #4404)
              rec_uses = [LStmtLR GhcRn GhcPs (LocatedA (body GhcPs))]
-> [(SrcSpan, [ImplicitFieldBinders])]
forall (idR :: Pass) (body :: * -> *).
[LStmtLR GhcRn (GhcPass idR) (LocatedA (body (GhcPass idR)))]
-> [(SrcSpan, [ImplicitFieldBinders])]
lStmtsImplicits (((GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)
 -> GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))))
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
     FreeVars)]
-> [GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))]
forall a b. (a -> b) -> [a] -> [b]
map (GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> GenLocated
     SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))
forall a b. (a, b) -> a
fst [(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)]
new_lhs_and_fv)
              implicit_uses = [Name] -> FreeVars
mkNameSet ([Name] -> FreeVars) -> [Name] -> FreeVars
forall a b. (a -> b) -> a -> b
$ ((SrcSpan, [ImplicitFieldBinders]) -> [Name])
-> [(SrcSpan, [ImplicitFieldBinders])] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap ((ImplicitFieldBinders -> [Name])
-> [ImplicitFieldBinders] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap ImplicitFieldBinders -> [Name]
implFlBndr_binders ([ImplicitFieldBinders] -> [Name])
-> ((SrcSpan, [ImplicitFieldBinders]) -> [ImplicitFieldBinders])
-> (SrcSpan, [ImplicitFieldBinders])
-> [Name]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (SrcSpan, [ImplicitFieldBinders]) -> [ImplicitFieldBinders]
forall a b. (a, b) -> b
snd) ([(SrcSpan, [ImplicitFieldBinders])] -> [Name])
-> [(SrcSpan, [ImplicitFieldBinders])] -> [Name]
forall a b. (a -> b) -> a -> b
$ [(SrcSpan, [ImplicitFieldBinders])]
rec_uses
        ; bindLocalNamesFV bound_names $
          addLocalFixities fix_env bound_names $ do

          -- (C) do the right-hand-sides and thing-inside
        { segs <- rn_rec_stmts ctxt rnBody bound_names new_lhs_and_fv
        ; (res, fvs) <- cont segs
        ; mapM_ (\(SrcSpan
loc, [ImplicitFieldBinders]
ns) -> SrcSpan
-> FreeVars
-> Maybe [ImplicitFieldBinders]
-> IOEnv (Env TcGblEnv TcLclEnv) ()
checkUnusedRecordWildcard SrcSpan
loc FreeVars
fvs ([ImplicitFieldBinders] -> Maybe [ImplicitFieldBinders]
forall a. a -> Maybe a
Just [ImplicitFieldBinders]
ns))
                rec_uses
        ; warnUnusedLocalBinds bound_names (fvs `unionNameSet` implicit_uses)
        ; return (res, fvs) }}

-- get all the fixity decls in any Let stmt
collectRecStmtsFixities :: [LStmtLR GhcPs GhcPs body] -> [LFixitySig GhcPs]
collectRecStmtsFixities :: forall body. [LStmtLR GhcPs GhcPs body] -> [LFixitySig GhcPs]
collectRecStmtsFixities [LStmtLR GhcPs GhcPs body]
l =
    (GenLocated
   (Anno (StmtLR GhcPs GhcPs body)) (StmtLR GhcPs GhcPs body)
 -> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
 -> [GenLocated SrcSpanAnnA (FixitySig GhcPs)])
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
-> [GenLocated
      (Anno (StmtLR GhcPs GhcPs body)) (StmtLR GhcPs GhcPs body)]
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr (\ GenLocated
  (Anno (StmtLR GhcPs GhcPs body)) (StmtLR GhcPs GhcPs body)
s -> \[GenLocated SrcSpanAnnA (FixitySig GhcPs)]
acc -> case GenLocated
  (Anno (StmtLR GhcPs GhcPs body)) (StmtLR GhcPs GhcPs body)
s of
            (L Anno (StmtLR GhcPs GhcPs body)
_ (LetStmt XLetStmt GhcPs GhcPs body
_ (HsValBinds XHsValBinds GhcPs GhcPs
_ (ValBinds XValBinds GhcPs GhcPs
_ LHsBindsLR GhcPs GhcPs
_ [LSig GhcPs]
sigs)))) ->
              (GenLocated SrcSpanAnnA (Sig GhcPs)
 -> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
 -> [GenLocated SrcSpanAnnA (FixitySig GhcPs)])
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
-> [GenLocated SrcSpanAnnA (Sig GhcPs)]
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr (\ GenLocated SrcSpanAnnA (Sig GhcPs)
sig -> \ [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
acc -> case GenLocated SrcSpanAnnA (Sig GhcPs)
sig of
                                         (L SrcSpanAnnA
loc (FixSig XFixSig GhcPs
_ FixitySig GhcPs
s)) -> (SrcSpanAnnA
-> FixitySig GhcPs -> GenLocated SrcSpanAnnA (FixitySig GhcPs)
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc FixitySig GhcPs
s) GenLocated SrcSpanAnnA (FixitySig GhcPs)
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
-> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
forall a. a -> [a] -> [a]
: [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
acc
                                         GenLocated SrcSpanAnnA (Sig GhcPs)
_ -> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
acc) [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
acc [LSig GhcPs]
[GenLocated SrcSpanAnnA (Sig GhcPs)]
sigs
            GenLocated
  (Anno (StmtLR GhcPs GhcPs body)) (StmtLR GhcPs GhcPs body)
_ -> [GenLocated SrcSpanAnnA (FixitySig GhcPs)]
acc) [] [LStmtLR GhcPs GhcPs body]
[GenLocated
   (Anno (StmtLR GhcPs GhcPs body)) (StmtLR GhcPs GhcPs body)]
l

-- left-hand sides

rn_rec_stmt_lhs :: AnnoBody body => MiniFixityEnv
                -> LStmt GhcPs (LocatedA (body GhcPs))
                   -- rename LHS, and return its FVs
                   -- Warning: we will only need the FreeVars below in the case of a BindStmt,
                   -- so we don't bother to compute it accurately in the other cases
                -> RnM [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]

rn_rec_stmt_lhs :: forall (body :: * -> *).
AnnoBody body =>
MiniFixityEnv
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
rn_rec_stmt_lhs MiniFixityEnv
_ (L SrcSpanAnnA
loc (BodyStmt XBodyStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ LocatedA (body GhcPs)
body SyntaxExpr GhcPs
a SyntaxExpr GhcPs
b))
  = [(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return [(SrcSpanAnnA
-> StmtLR GhcRn GhcPs (LocatedA (body GhcPs))
-> GenLocated
     SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc (XBodyStmt GhcRn GhcPs (LocatedA (body GhcPs))
-> LocatedA (body GhcPs)
-> SyntaxExpr GhcPs
-> SyntaxExpr GhcPs
-> StmtLR GhcRn GhcPs (LocatedA (body GhcPs))
forall idL idR body.
XBodyStmt idL idR body
-> body -> SyntaxExpr idR -> SyntaxExpr idR -> StmtLR idL idR body
BodyStmt XBodyStmt GhcRn GhcPs (LocatedA (body GhcPs))
NoExtField
noExtField LocatedA (body GhcPs)
body SyntaxExpr GhcPs
a SyntaxExpr GhcPs
b), FreeVars
emptyFVs)]

rn_rec_stmt_lhs MiniFixityEnv
_ (L SrcSpanAnnA
loc (LastStmt XLastStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ LocatedA (body GhcPs)
body Maybe Bool
noret SyntaxExpr GhcPs
a))
  = [(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return [(SrcSpanAnnA
-> StmtLR GhcRn GhcPs (LocatedA (body GhcPs))
-> GenLocated
     SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc (XLastStmt GhcRn GhcPs (LocatedA (body GhcPs))
-> LocatedA (body GhcPs)
-> Maybe Bool
-> SyntaxExpr GhcPs
-> StmtLR GhcRn GhcPs (LocatedA (body GhcPs))
forall idL idR body.
XLastStmt idL idR body
-> body -> Maybe Bool -> SyntaxExpr idR -> StmtLR idL idR body
LastStmt XLastStmt GhcRn GhcPs (LocatedA (body GhcPs))
NoExtField
noExtField LocatedA (body GhcPs)
body Maybe Bool
noret SyntaxExpr GhcPs
a), FreeVars
emptyFVs)]

rn_rec_stmt_lhs MiniFixityEnv
fix_env (L SrcSpanAnnA
loc (BindStmt XBindStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ LPat GhcPs
pat LocatedA (body GhcPs)
body))
  = do
      -- should the ctxt be MDo instead?
      (pat', fv_pat) <- NameMaker -> LPat GhcPs -> RnM (LPat GhcRn, FreeVars)
rnBindPat (MiniFixityEnv -> NameMaker
localRecNameMaker MiniFixityEnv
fix_env) LPat GhcPs
pat
      return [(L loc (BindStmt noAnn pat' body), fv_pat)]

rn_rec_stmt_lhs MiniFixityEnv
_ (L SrcSpanAnnA
_ (LetStmt XLetStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ binds :: HsLocalBinds GhcPs
binds@(HsIPBinds {})))
  = TcRnMessage
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. TcRnMessage -> TcRn a
failWith (Either (HsLocalBinds GhcPs) (HsLocalBindsLR GhcRn GhcPs)
-> TcRnMessage
badIpBinds (HsLocalBinds GhcPs
-> Either (HsLocalBinds GhcPs) (HsLocalBindsLR GhcRn GhcPs)
forall a b. a -> Either a b
Left HsLocalBinds GhcPs
binds))


rn_rec_stmt_lhs MiniFixityEnv
fix_env (L SrcSpanAnnA
loc (LetStmt XLetStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ (HsValBinds XHsValBinds GhcPs GhcPs
x HsValBindsLR GhcPs GhcPs
binds)))
    = do (_bound_names, binds') <- MiniFixityEnv
-> HsValBindsLR GhcPs GhcPs
-> RnM ([Name], HsValBindsLR GhcRn GhcPs)
rnLocalValBindsLHS MiniFixityEnv
fix_env HsValBindsLR GhcPs GhcPs
binds
         return [(L loc (LetStmt noAnn (HsValBinds x binds')),
                 -- Warning: this is bogus; see function invariant
                 emptyFVs
                 )]

-- XXX Do we need to do something with the return and mfix names?
rn_rec_stmt_lhs MiniFixityEnv
fix_env (L SrcSpanAnnA
_ (RecStmt { recS_stmts :: forall idL idR body.
StmtLR idL idR body -> XRec idR [LStmtLR idL idR body]
recS_stmts = L SrcSpanAnnL
_ [GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
stmts }))  -- Flatten Rec inside Rec
    = MiniFixityEnv
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(XRec GhcRn (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall (body :: * -> *).
AnnoBody body =>
MiniFixityEnv
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> RnM [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
rn_rec_stmts_lhs MiniFixityEnv
fix_env [LStmt GhcPs (LocatedA (body GhcPs))]
[GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
stmts

rn_rec_stmt_lhs MiniFixityEnv
_ stmt :: LStmt GhcPs (LocatedA (body GhcPs))
stmt@(L SrcSpanAnnA
_ (ParStmt {}))       -- Syntactically illegal in mdo
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt" (GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> SDoc
forall a. Outputable a => a -> SDoc
ppr LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
stmt)

rn_rec_stmt_lhs MiniFixityEnv
_ stmt :: LStmt GhcPs (LocatedA (body GhcPs))
stmt@(L SrcSpanAnnA
_ (TransStmt {}))     -- Syntactically illegal in mdo
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt" (GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> SDoc
forall a. Outputable a => a -> SDoc
ppr LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
stmt)

rn_rec_stmt_lhs MiniFixityEnv
_ stmt :: LStmt GhcPs (LocatedA (body GhcPs))
stmt@(L SrcSpanAnnA
_ (ApplicativeStmt {})) -- Shouldn't appear yet
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt" (GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> SDoc
forall a. Outputable a => a -> SDoc
ppr LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
stmt)

rn_rec_stmt_lhs MiniFixityEnv
_ (L SrcSpanAnnA
_ (LetStmt XLetStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ (EmptyLocalBinds XEmptyLocalBinds GhcPs GhcPs
_)))
  = String
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall a. HasCallStack => String -> a
panic String
"rn_rec_stmt LetStmt EmptyLocalBinds"

rn_rec_stmts_lhs :: AnnoBody body => MiniFixityEnv
                 -> [LStmt GhcPs (LocatedA (body GhcPs))]
                 -> RnM [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
rn_rec_stmts_lhs :: forall (body :: * -> *).
AnnoBody body =>
MiniFixityEnv
-> [LStmt GhcPs (LocatedA (body GhcPs))]
-> RnM [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
rn_rec_stmts_lhs MiniFixityEnv
fix_env [LStmt GhcPs (LocatedA (body GhcPs))]
stmts
  = do { ls <- (GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      [(GenLocated
          SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
        FreeVars)])
-> [GenLocated
      SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall (m :: * -> *) (f :: * -> *) a b.
(Monad m, Traversable f) =>
(a -> m [b]) -> f a -> m [b]
concatMapM (MiniFixityEnv
-> LStmt GhcPs (LocatedA (body GhcPs))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(XRec GhcRn (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
       FreeVars)]
forall (body :: * -> *).
AnnoBody body =>
MiniFixityEnv
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
rn_rec_stmt_lhs MiniFixityEnv
fix_env) [LStmt GhcPs (LocatedA (body GhcPs))]
[GenLocated
   SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))]
stmts
       ; let boundNames = CollectFlag GhcRn
-> [XRec GhcRn (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))]
-> [IdP GhcRn]
forall (idL :: Pass) (idR :: Pass) body.
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> [LStmtLR (GhcPass idL) (GhcPass idR) body]
-> [IdP (GhcPass idL)]
collectLStmtsBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders (((GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)
 -> GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))))
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
     FreeVars)]
-> [GenLocated
      SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))]
forall a b. (a -> b) -> [a] -> [b]
map (GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> GenLocated
     SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs)))
forall a b. (a, b) -> a
fst [(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)]
ls)
            -- First do error checking: we need to check for dups here because we
            -- don't bind all of the variables from the Stmt at once
            -- with bindLocatedLocals.
       ; checkDupNames boundNames
       ; return ls }


-- right-hand-sides

rn_rec_stmt :: AnnoBody body =>
               HsStmtContextRn
            -> (body GhcPs -> RnM (body GhcRn, FreeVars))
            -> [Name]
            -> (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
            -> RnM [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
        -- Rename a Stmt that is inside a RecStmt (or mdo)
        -- Assumes all binders are already in scope
        -- Turns each stmt into a singleton Stmt
rn_rec_stmt :: forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [Name]
-> (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
-> RnM [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
rn_rec_stmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [Name]
_ (L SrcSpanAnnA
loc (LastStmt XLastStmt GhcRn GhcPs (LocatedA (body GhcPs))
_ (L SrcSpanAnnA
lb body GhcPs
body) Maybe Bool
noret SyntaxExpr GhcPs
_), FreeVars
_)
  = do  { (body', fv_expr) <- body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody body GhcPs
body
        ; (ret_op, fvs1)   <- lookupQualifiedDo ctxt returnMName
        ; return [(emptyNameSet, fv_expr `plusFV` fvs1, emptyNameSet,
                   L loc (LastStmt noExtField (L lb body') noret ret_op))] }

rn_rec_stmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [Name]
_ (L SrcSpanAnnA
loc (BodyStmt XBodyStmt GhcRn GhcPs (LocatedA (body GhcPs))
_ (L SrcSpanAnnA
lb body GhcPs
body) SyntaxExpr GhcPs
_ SyntaxExpr GhcPs
_), FreeVars
_)
  = do { (body', fvs) <- body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody body GhcPs
body
       ; (then_op, fvs1) <- lookupQualifiedDo ctxt thenMName
       ; return [(emptyNameSet, fvs `plusFV` fvs1, emptyNameSet,
                 L loc (BodyStmt noExtField (L lb body') then_op noSyntaxExpr))] }

rn_rec_stmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [Name]
_ (L SrcSpanAnnA
loc (BindStmt XBindStmt GhcRn GhcPs (LocatedA (body GhcPs))
_ LPat GhcRn
pat' (L SrcSpanAnnA
lb body GhcPs
body)), FreeVars
fv_pat)
  = do { (body', fv_expr) <- body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody body GhcPs
body
       ; (bind_op, fvs1) <- lookupQualifiedDo ctxt bindMName

       ; (fail_op, fvs2) <- getMonadFailOp ctxt

       ; let bndrs = [Name] -> FreeVars
mkNameSet (CollectFlag GhcRn -> LPat GhcRn -> [IdP GhcRn]
forall p. CollectPass p => CollectFlag p -> LPat p -> [IdP p]
collectPatBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders LPat GhcRn
pat')
             fvs   = FreeVars
fv_expr FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fv_pat FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs1 FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs2
       ; let xbsrn = XBindStmtRn { xbsrn_bindOp :: SyntaxExpr GhcRn
xbsrn_bindOp = SyntaxExpr GhcRn
SyntaxExprRn
bind_op, xbsrn_failOp :: Maybe (SyntaxExpr GhcRn)
xbsrn_failOp = Maybe (SyntaxExpr GhcRn)
Maybe SyntaxExprRn
fail_op }
       ; return [(bndrs, fvs, bndrs `intersectNameSet` fvs,
                  L loc (BindStmt xbsrn pat' (L lb body')))] }

rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
_ (L SrcSpanAnnA
_ (LetStmt XLetStmt GhcRn GhcPs (LocatedA (body GhcPs))
_ binds :: HsLocalBindsLR GhcRn GhcPs
binds@(HsIPBinds {})), FreeVars
_)
  = TcRnMessage
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall a. TcRnMessage -> TcRn a
failWith (Either (HsLocalBinds GhcPs) (HsLocalBindsLR GhcRn GhcPs)
-> TcRnMessage
badIpBinds (HsLocalBindsLR GhcRn GhcPs
-> Either (HsLocalBinds GhcPs) (HsLocalBindsLR GhcRn GhcPs)
forall a b. b -> Either a b
Right HsLocalBindsLR GhcRn GhcPs
binds))

rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
all_bndrs (L SrcSpanAnnA
loc (LetStmt XLetStmt GhcRn GhcPs (LocatedA (body GhcPs))
_ (HsValBinds XHsValBinds GhcRn GhcPs
x HsValBindsLR GhcRn GhcPs
binds')), FreeVars
_)
  = do { (binds', du_binds) <- FreeVars
-> HsValBindsLR GhcRn GhcPs -> RnM (HsValBinds GhcRn, DefUses)
rnLocalValBindsRHS ([Name] -> FreeVars
mkNameSet [Name]
all_bndrs) HsValBindsLR GhcRn GhcPs
binds'
           -- fixities and unused are handled above in rnRecStmtsAndThen
       ; let fvs = DefUses -> FreeVars
allUses DefUses
du_binds
       ; return [(duDefs du_binds, fvs, emptyNameSet,
                 L loc (LetStmt noAnn (HsValBinds x binds')))] }

-- no RecStmt case because they get flattened above when doing the LHSes
rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
_ stmt :: (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
stmt@(L SrcSpanAnnA
_ (RecStmt {}), FreeVars
_)
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt: RecStmt" ((GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> SDoc
forall a. Outputable a => a -> SDoc
ppr (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
(GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
stmt)

rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
_ stmt :: (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
stmt@(L SrcSpanAnnA
_ (ParStmt {}), FreeVars
_)       -- Syntactically illegal in mdo
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt: ParStmt" ((GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> SDoc
forall a. Outputable a => a -> SDoc
ppr (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
(GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
stmt)

rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
_ stmt :: (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
stmt@(L SrcSpanAnnA
_ (TransStmt {}), FreeVars
_)     -- Syntactically illegal in mdo
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt: TransStmt" ((GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> SDoc
forall a. Outputable a => a -> SDoc
ppr (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
(GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
stmt)

rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
_ (L SrcSpanAnnA
_ (LetStmt XLetStmt GhcRn GhcPs (LocatedA (body GhcPs))
_ (EmptyLocalBinds XEmptyLocalBinds GhcRn GhcPs
_)), FreeVars
_)
  = String
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall a. HasCallStack => String -> a
panic String
"rn_rec_stmt: LetStmt EmptyLocalBinds"

rn_rec_stmt HsStmtContextRn
_ body GhcPs -> RnM (body GhcRn, FreeVars)
_ [Name]
_ stmt :: (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
stmt@(L SrcSpanAnnA
_ (ApplicativeStmt {}), FreeVars
_)
  = String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       GenLocated
         SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"rn_rec_stmt: ApplicativeStmt" ((GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
-> SDoc
forall a. Outputable a => a -> SDoc
ppr (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
(GenLocated
   SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
 FreeVars)
stmt)

rn_rec_stmts :: AnnoBody body
             => HsStmtContextRn
             -> (body GhcPs -> RnM (body GhcRn, FreeVars))
             -> [Name]
             -> [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
             -> RnM [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
rn_rec_stmts :: forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [Name]
-> [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
-> RnM [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
rn_rec_stmts HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [Name]
bndrs [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
stmts
  = do { segs_s <- ((GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      [Segment
         (GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))])
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
     FreeVars)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [[Segment
         (GenLocated
            SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM (HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [Name]
-> (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(FreeVars, FreeVars, FreeVars,
       XRec GhcRn (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))))]
forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> (body GhcPs -> RnM (body GhcRn, FreeVars))
-> [Name]
-> (LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)
-> RnM [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
rn_rec_stmt HsStmtContextRn
ctxt body GhcPs -> RnM (body GhcRn, FreeVars)
rnBody [Name]
bndrs) [(LStmtLR GhcRn GhcPs (LocatedA (body GhcPs)), FreeVars)]
[(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcPs (LocatedA (body GhcPs))),
  FreeVars)]
stmts
       ; return (concat segs_s) }

---------------------------------------------
segmentRecStmts :: SrcSpan -> HsStmtContextRn
                -> Stmt GhcRn (LocatedA (body GhcRn))
                -> [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
                -> (FreeVars, Bool)
                    -- ^ The free variables used in later statements.
                    -- If the boolean is 'True', this might be an underestimate
                    -- because we are in GHCi, and might thus be missing some "used later"
                    -- FVs. See Note [What is "used later" in a rec stmt]
                -> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)

segmentRecStmts :: forall (body :: * -> *).
SrcSpan
-> HsStmtContextRn
-> Stmt GhcRn (LocatedA (body GhcRn))
-> [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
-> (FreeVars, Bool)
-> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
segmentRecStmts SrcSpan
loc HsStmtContextRn
ctxt Stmt GhcRn (LocatedA (body GhcRn))
empty_rec_stmt [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
segs (FreeVars
fvs_later, Bool
might_be_more_fvs_later)
  | [Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
-> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
[Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
segs
  = ([], FreeVars
final_fv_uses)

  | HsDoStmt (MDoExpr Maybe ModuleName
_) <- HsStmtContextRn
ctxt
  = Stmt GhcRn (LocatedA (body GhcRn))
-> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
-> FreeVars
-> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
forall (body :: * -> *).
Stmt GhcRn (LocatedA (body GhcRn))
-> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
-> FreeVars
-> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
segsToStmts Stmt GhcRn (LocatedA (body GhcRn))
empty_rec_stmt [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
grouped_segs FreeVars
fvs_later
               -- Step 4: Turn the segments into Stmts
                --         Use RecStmt when and only when there are fwd refs
                --         Also gather up the uses from the end towards the
                --         start, so we can tell the RecStmt which things are
                --         used 'after' the RecStmt

  | Bool
otherwise
  = ([ SrcSpanAnnA
-> Stmt GhcRn (LocatedA (body GhcRn))
-> GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
forall l e. l -> e -> GenLocated l e
L (SrcSpan -> SrcSpanAnnA
forall e. HasAnnotation e => SrcSpan -> e
noAnnSrcSpan SrcSpan
loc) (Stmt GhcRn (LocatedA (body GhcRn))
 -> GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))
-> Stmt GhcRn (LocatedA (body GhcRn))
-> GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
forall a b. (a -> b) -> a -> b
$
       Stmt GhcRn (LocatedA (body GhcRn))
empty_rec_stmt { recS_stmts = noLocA ss
                      , recS_later_ids = nameSetElemsStable final_fvs_later
                      , recS_rec_ids   = nameSetElemsStable
                                           (defs `intersectNameSet` uses) }]
          -- See Note [Deterministic ApplicativeDo and RecursiveDo desugaring]
    , FreeVars
uses FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
final_fv_uses)

  where
    (FreeVars
final_fv_uses, FreeVars
final_fvs_later)
      | Bool
might_be_more_fvs_later
      = (FreeVars
defs, FreeVars
defs)
        -- If there might be more uses later (e.g. we are in GHCi and have not
        -- yet seen the whole rec statement), conservatively assume that everything
        -- will be used later (as is possible).
      | Bool
otherwise
      = ( FreeVars
uses FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fvs_later
        , FreeVars
defs FreeVars -> FreeVars -> FreeVars
`intersectNameSet` FreeVars
fvs_later )

    ([FreeVars]
defs_s, [FreeVars]
uses_s, [FreeVars]
_, [GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
ss) = [Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
-> ([FreeVars], [FreeVars], [FreeVars],
    [GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))])
forall a b c d. [(a, b, c, d)] -> ([a], [b], [c], [d])
unzip4 [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
[Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
segs
    defs :: FreeVars
defs = [FreeVars] -> FreeVars
plusFVs [FreeVars]
defs_s
    uses :: FreeVars
uses = [FreeVars] -> FreeVars
plusFVs [FreeVars]
uses_s

                -- Step 2: Fill in the fwd refs.
                --         The segments are all singletons, but their fwd-ref
                --         field mentions all the things used by the segment
                --         that are bound after their use
    segs_w_fwd_refs :: [Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
segs_w_fwd_refs = [Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
-> [Segment
      (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
forall a. [Segment a] -> [Segment a]
addFwdRefs [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
[Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
segs

                -- Step 3: Group together the segments to make bigger segments
                --         Invariant: in the result, no segment uses a variable
                --                    bound in a later segment
    grouped_segs :: [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
grouped_segs = HsStmtContextRn
-> [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
-> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
forall body.
HsStmtContextRn
-> [Segment (LStmt GhcRn body)] -> [Segment [LStmt GhcRn body]]
glomSegments HsStmtContextRn
ctxt [Segment (LStmt GhcRn (LocatedA (body GhcRn)))]
[Segment
   (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn))))]
segs_w_fwd_refs

----------------------------
addFwdRefs :: [Segment a] -> [Segment a]
-- So far the segments only have forward refs *within* the Stmt
--      (which happens for bind:  x <- ...x...)
-- This function adds the cross-seg fwd ref info

addFwdRefs :: forall a. [Segment a] -> [Segment a]
addFwdRefs [Segment a]
segs
  = ([Segment a], FreeVars) -> [Segment a]
forall a b. (a, b) -> a
fst ((Segment a -> ([Segment a], FreeVars) -> ([Segment a], FreeVars))
-> ([Segment a], FreeVars)
-> [Segment a]
-> ([Segment a], FreeVars)
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr Segment a -> ([Segment a], FreeVars) -> ([Segment a], FreeVars)
forall {d}.
(FreeVars, FreeVars, FreeVars, d)
-> ([(FreeVars, FreeVars, FreeVars, d)], FreeVars)
-> ([(FreeVars, FreeVars, FreeVars, d)], FreeVars)
mk_seg ([], FreeVars
emptyNameSet) [Segment a]
segs)
  where
    mk_seg :: (FreeVars, FreeVars, FreeVars, d)
-> ([(FreeVars, FreeVars, FreeVars, d)], FreeVars)
-> ([(FreeVars, FreeVars, FreeVars, d)], FreeVars)
mk_seg (FreeVars
defs, FreeVars
uses, FreeVars
fwds, d
stmts) ([(FreeVars, FreeVars, FreeVars, d)]
segs, FreeVars
later_defs)
        = ((FreeVars, FreeVars, FreeVars, d)
new_seg (FreeVars, FreeVars, FreeVars, d)
-> [(FreeVars, FreeVars, FreeVars, d)]
-> [(FreeVars, FreeVars, FreeVars, d)]
forall a. a -> [a] -> [a]
: [(FreeVars, FreeVars, FreeVars, d)]
segs, FreeVars
all_defs)
        where
          new_seg :: (FreeVars, FreeVars, FreeVars, d)
new_seg = (FreeVars
defs, FreeVars
uses, FreeVars
new_fwds, d
stmts)
          all_defs :: FreeVars
all_defs = FreeVars
later_defs FreeVars -> FreeVars -> FreeVars
`unionNameSet` FreeVars
defs
          new_fwds :: FreeVars
new_fwds = FreeVars
fwds FreeVars -> FreeVars -> FreeVars
`unionNameSet` (FreeVars
uses FreeVars -> FreeVars -> FreeVars
`intersectNameSet` FreeVars
later_defs)
                -- Add the downstream fwd refs here

{-
Note [Segmenting mdo]
~~~~~~~~~~~~~~~~~~~~~
NB. June 7 2012: We only glom segments that appear in an explicit mdo;
and leave those found in "do rec"'s intact.  See
https://gitlab.haskell.org/ghc/ghc/issues/4148 for the discussion
leading to this design choice.  Hence the test in segmentRecStmts.

Note [Glomming segments]
~~~~~~~~~~~~~~~~~~~~~~~~
Glomming the singleton segments of an mdo into minimal recursive groups.

At first I thought this was just strongly connected components, but
there's an important constraint: the order of the stmts must not change.

Consider
     mdo { x <- ...y...
           p <- z
           y <- ...x...
           q <- x
           z <- y
           r <- x }

Here, the first stmt mention 'y', which is bound in the third.
But that means that the innocent second stmt (p <- z) gets caught
up in the recursion.  And that in turn means that the binding for
'z' has to be included... and so on.

Start at the tail { r <- x }
Now add the next one { z <- y ; r <- x }
Now add one more     { q <- x ; z <- y ; r <- x }
Now one more... but this time we have to group a bunch into rec
     { rec { y <- ...x... ; q <- x ; z <- y } ; r <- x }
Now one more, which we can add on without a rec
     { p <- z ;
       rec { y <- ...x... ; q <- x ; z <- y } ;
       r <- x }
Finally we add the last one; since it mentions y we have to
glom it together with the first two groups
     { rec { x <- ...y...; p <- z ; y <- ...x... ;
             q <- x ; z <- y } ;
       r <- x }

Note [What is "used later" in a rec stmt]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We desugar a recursive Stmt to something like

  (a,_,c) <- mfix (\(a,b,_) -> do { ... ; return (a,b,c) })
  ...stuff after the rec...

The knot-tied tuple must contain
* All the variables that are used before they are bound in the `rec` block
* All the variables that are used after the entire `rec` block

In the case of GHCi, however, we don't know what variables will be used
after the `rec` (#20206).  For example, we might have
    ghci>  rec { x <- e1; y <- e2 }
    ghci>  print x
    ghci>  print y

So we have to assume that *all* the variables bound in the `rec` are used
afterwards.  We pass a Boolean to segmentRecStmts to signal such a situation,
in which case that function conservatively assumes that everything might well
be used later.
-}

glomSegments :: HsStmtContextRn
             -> [Segment (LStmt GhcRn body)]
             -> [Segment [LStmt GhcRn body]]
                                  -- Each segment has a non-empty list of Stmts
-- See Note [Glomming segments]

glomSegments :: forall body.
HsStmtContextRn
-> [Segment (LStmt GhcRn body)] -> [Segment [LStmt GhcRn body]]
glomSegments HsStmtContextRn
_ [] = []
glomSegments HsStmtContextRn
ctxt ((FreeVars
defs,FreeVars
uses,FreeVars
fwds,LStmt GhcRn body
stmt) : [Segment (LStmt GhcRn body)]
segs)
        -- Actually stmts will always be a singleton
  = (FreeVars
seg_defs, FreeVars
seg_uses, FreeVars
seg_fwds, [GenLocated
   (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]
seg_stmts)  Segment
  [GenLocated
     (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]
-> [Segment
      [GenLocated
         (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
-> [Segment
      [GenLocated
         (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
forall a. a -> [a] -> [a]
: [Segment
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
others
  where
    segs' :: [(FreeVars, FreeVars, FreeVars, [LStmt GhcRn body])]
segs'            = HsStmtContextRn
-> [Segment (LStmt GhcRn body)]
-> [(FreeVars, FreeVars, FreeVars, [LStmt GhcRn body])]
forall body.
HsStmtContextRn
-> [Segment (LStmt GhcRn body)] -> [Segment [LStmt GhcRn body]]
glomSegments HsStmtContextRn
ctxt [Segment (LStmt GhcRn body)]
segs
    ([Segment
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
extras, [Segment
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
others) = FreeVars
-> [Segment
      [GenLocated
         (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
-> ([Segment
       [GenLocated
          (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]],
    [Segment
       [GenLocated
          (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]])
forall a. FreeVars -> [Segment a] -> ([Segment a], [Segment a])
grab FreeVars
uses [(FreeVars, FreeVars, FreeVars, [LStmt GhcRn body])]
[Segment
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
segs'
    ([FreeVars]
ds, [FreeVars]
us, [FreeVars]
fs, [[GenLocated
    (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
ss) = [Segment
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
-> ([FreeVars], [FreeVars], [FreeVars],
    [[GenLocated
        (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]])
forall a b c d. [(a, b, c, d)] -> ([a], [b], [c], [d])
unzip4 [Segment
   [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
extras

    seg_defs :: FreeVars
seg_defs  = [FreeVars] -> FreeVars
plusFVs [FreeVars]
ds FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
defs
    seg_uses :: FreeVars
seg_uses  = [FreeVars] -> FreeVars
plusFVs [FreeVars]
us FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
uses
    seg_fwds :: FreeVars
seg_fwds  = [FreeVars] -> FreeVars
plusFVs [FreeVars]
fs FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
fwds
    seg_stmts :: [GenLocated
   (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]
seg_stmts = LStmt GhcRn body
GenLocated
  (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)
stmt GenLocated
  (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)
-> [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]
-> [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]
forall a. a -> [a] -> [a]
: [[GenLocated
    (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
-> [GenLocated
      (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat [[GenLocated
    (Anno (StmtLR GhcRn GhcRn body)) (StmtLR GhcRn GhcRn body)]]
ss

    grab :: NameSet             -- The client
         -> [Segment a]
         -> ([Segment a],       -- Needed by the 'client'
             [Segment a])       -- Not needed by the client
        -- The result is simply a split of the input
    grab :: forall a. FreeVars -> [Segment a] -> ([Segment a], [Segment a])
grab FreeVars
uses [Segment a]
dus
        = ([Segment a] -> [Segment a]
forall a. [a] -> [a]
reverse [Segment a]
yeses, [Segment a] -> [Segment a]
forall a. [a] -> [a]
reverse [Segment a]
noes)
        where
          ([Segment a]
noes, [Segment a]
yeses)           = (Segment a -> Bool) -> [Segment a] -> ([Segment a], [Segment a])
forall a. (a -> Bool) -> [a] -> ([a], [a])
span Segment a -> Bool
not_needed ([Segment a] -> [Segment a]
forall a. [a] -> [a]
reverse [Segment a]
dus)
          not_needed :: Segment a -> Bool
not_needed (FreeVars
defs,FreeVars
_,FreeVars
_,a
_) = FreeVars -> FreeVars -> Bool
disjointNameSet FreeVars
defs FreeVars
uses

----------------------------------------------------
segsToStmts :: Stmt GhcRn (LocatedA (body GhcRn))
                                  -- A RecStmt with the SyntaxOps filled in
            -> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
                                  -- Each Segment has a non-empty list of Stmts
            -> FreeVars           -- Free vars used 'later'
            -> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)

segsToStmts :: forall (body :: * -> *).
Stmt GhcRn (LocatedA (body GhcRn))
-> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
-> FreeVars
-> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
segsToStmts Stmt GhcRn (LocatedA (body GhcRn))
_ [] FreeVars
fvs_later = ([], FreeVars
fvs_later)
segsToStmts Stmt GhcRn (LocatedA (body GhcRn))
empty_rec_stmt ((FreeVars
defs, FreeVars
uses, FreeVars
fwds, [LStmt GhcRn (LocatedA (body GhcRn))]
ss) : [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
segs) FreeVars
fvs_later
  = Bool
-> ([GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))],
    FreeVars)
-> ([GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))],
    FreeVars)
forall a. HasCallStack => Bool -> a -> a
assert (Bool -> Bool
not ([GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
-> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [LStmt GhcRn (LocatedA (body GhcRn))]
[GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
ss))
    (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
new_stmt GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
-> [GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
-> [GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
forall a. a -> [a] -> [a]
: [LStmt GhcRn (LocatedA (body GhcRn))]
[GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
later_stmts, FreeVars
later_uses FreeVars -> FreeVars -> FreeVars
`plusFV` FreeVars
uses)
  where
    ([LStmt GhcRn (LocatedA (body GhcRn))]
later_stmts, FreeVars
later_uses) = Stmt GhcRn (LocatedA (body GhcRn))
-> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
-> FreeVars
-> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
forall (body :: * -> *).
Stmt GhcRn (LocatedA (body GhcRn))
-> [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
-> FreeVars
-> ([LStmt GhcRn (LocatedA (body GhcRn))], FreeVars)
segsToStmts Stmt GhcRn (LocatedA (body GhcRn))
empty_rec_stmt [Segment [LStmt GhcRn (LocatedA (body GhcRn))]]
segs FreeVars
fvs_later
    new_stmt :: GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
new_stmt | Bool
non_rec   = [GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
-> GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
forall a. HasCallStack => [a] -> a
head [LStmt GhcRn (LocatedA (body GhcRn))]
[GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
ss
             | Bool
otherwise = SrcSpanAnnA
-> Stmt GhcRn (LocatedA (body GhcRn))
-> GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
forall l e. l -> e -> GenLocated l e
L (GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
-> SrcSpanAnnA
forall l e. GenLocated l e -> l
getLoc ([GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
-> GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))
forall a. HasCallStack => [a] -> a
head [LStmt GhcRn (LocatedA (body GhcRn))]
[GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
ss)) Stmt GhcRn (LocatedA (body GhcRn))
rec_stmt
    rec_stmt :: Stmt GhcRn (LocatedA (body GhcRn))
rec_stmt = Stmt GhcRn (LocatedA (body GhcRn))
empty_rec_stmt { recS_stmts     = noLocA ss
                              , recS_later_ids = nameSetElemsStable used_later
                              , recS_rec_ids   = nameSetElemsStable fwds }
          -- See Note [Deterministic ApplicativeDo and RecursiveDo desugaring]
    non_rec :: Bool
non_rec    = [GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
-> Bool
forall a. [a] -> Bool
isSingleton [LStmt GhcRn (LocatedA (body GhcRn))]
[GenLocated SrcSpanAnnA (Stmt GhcRn (LocatedA (body GhcRn)))]
ss Bool -> Bool -> Bool
&& FreeVars -> Bool
isEmptyNameSet FreeVars
fwds
    used_later :: FreeVars
used_later = FreeVars
defs FreeVars -> FreeVars -> FreeVars
`intersectNameSet` FreeVars
later_uses
                                -- The ones needed after the RecStmt

{-
************************************************************************
*                                                                      *
ApplicativeDo
*                                                                      *
************************************************************************

Note [ApplicativeDo]
~~~~~~~~~~~~~~~~~~~~
= Example =

For a sequence of statements

 do
     x <- A
     y <- B x
     z <- C
     return (f x y z)

We want to transform this to

  (\(x,y) z -> f x y z) <$> (do x <- A; y <- B x; return (x,y)) <*> C

It would be easy to notice that "y <- B x" and "z <- C" are
independent and do something like this:

 do
     x <- A
     (y,z) <- (,) <$> B x <*> C
     return (f x y z)

But this isn't enough! If A and C were also independent, then this
transformation loses the ability to do A and C in parallel.

The algorithm works by first splitting the sequence of statements into
independent "segments", and a separate "tail" (the final statement). In
our example above, the segments would be

     [ x <- A
     , y <- B x ]

     [ z <- C ]

and the tail is:

     return (f x y z)

Then we take these segments and make an Applicative expression from them:

     (\(x,y) z -> return (f x y z))
       <$> do { x <- A; y <- B x; return (x,y) }
       <*> C

Finally, we recursively apply the transformation to each segment, to
discover any nested parallelism.

= Syntax & spec =

  expr ::= ... | do {stmt_1; ..; stmt_n} expr | ...

  stmt ::= pat <- expr
         | (arg_1 | ... | arg_n)  -- applicative composition, n>=1
         | ...                    -- other kinds of statement (e.g. let)

  arg ::= pat <- expr
        | {stmt_1; ..; stmt_n} {var_1..var_n}

(note that in the actual implementation,the expr in a do statement is
represented by a LastStmt as the final stmt, this is just a
representational issue and may change later.)

== Transformation to introduce applicative stmts ==

ado {} tail = tail
ado {pat <- expr} {return expr'} = (mkArg(pat <- expr)); return expr'
ado {one} tail = one : tail
ado stmts tail
  | n == 1 = ado before (ado after tail)
    where (before,after) = split(stmts_1)
  | n > 1  = (mkArg(stmts_1) | ... | mkArg(stmts_n)); tail
  where
    {stmts_1 .. stmts_n} = segments(stmts)

segments(stmts) =
  -- divide stmts into segments with no interdependencies

mkArg({pat <- expr}) = (pat <- expr)
mkArg({stmt_1; ...; stmt_n}) =
  {stmt_1; ...; stmt_n} {vars(stmt_1) u .. u vars(stmt_n)}

split({stmt_1; ..; stmt_n) =
  ({stmt_1; ..; stmt_i}, {stmt_i+1; ..; stmt_n})
  -- 1 <= i <= n
  -- i is a good place to insert a bind

== Desugaring for do ==

dsDo {} expr = expr

dsDo {pat <- rhs; stmts} expr =
   rhs >>= \pat -> dsDo stmts expr

dsDo {(arg_1 | ... | arg_n)} (return expr) =
  (\argpat (arg_1) .. argpat(arg_n) -> expr)
     <$> argexpr(arg_1)
     <*> ...
     <*> argexpr(arg_n)

dsDo {(arg_1 | ... | arg_n); stmts} expr =
  join (\argpat (arg_1) .. argpat(arg_n) -> dsDo stmts expr)
     <$> argexpr(arg_1)
     <*> ...
     <*> argexpr(arg_n)

== Special cases ==

If a do-expression contains only "return E" or "return $ E" plus
zero or more let-statements, we replace the "return" with "pure".
See Section 3.6 of the paper.

= Relevant modules in the rest of the compiler =

ApplicativeDo touches a few phases in the compiler:

* Renamer: The journey begins here in the renamer, where do-blocks are
  scheduled as outlined above and transformed into applicative
  combinators.  However, the code is still represented as a do-block
  with special forms of applicative statements. This allows us to
  recover the original do-block when e.g. printing type errors, where
  we don't want to show any of the applicative combinators since they
  don't exist in the source code.
  See ApplicativeStmt and ApplicativeArg in HsExpr.

* Typechecker: ApplicativeDo passes through the typechecker much like any
  other form of expression. The only crux is that the typechecker has to
  be aware of the special ApplicativeDo statements in the do-notation, and
  typecheck them appropriately.
  Relevant module: GHC.Tc.Gen.Match

* Desugarer: Any do-block which contains applicative statements is desugared
  as outlined above, to use the Applicative combinators.
  Relevant module: GHC.HsToCore.Expr

-}

-- | The 'Name's of @return@ and @pure@. These may not be 'returnName' and
-- 'pureName' due to @QualifiedDo@ or @RebindableSyntax@.
data MonadNames = MonadNames { MonadNames -> Name
return_name, MonadNames -> Name
pure_name :: Name }

instance Outputable MonadNames where
  ppr :: MonadNames -> SDoc
ppr (MonadNames {return_name :: MonadNames -> Name
return_name=Name
return_name,pure_name :: MonadNames -> Name
pure_name=Name
pure_name}) =
    [SDoc] -> SDoc
forall doc. IsLine doc => [doc] -> doc
hcat
    [String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"MonadNames { return_name = "
    ,Name -> SDoc
forall a. Outputable a => a -> SDoc
ppr Name
return_name
    ,String -> SDoc
forall doc. IsLine doc => String -> doc
text String
", pure_name = "
    ,Name -> SDoc
forall a. Outputable a => a -> SDoc
ppr Name
pure_name
    ,String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"}"
    ]

-- | rearrange a list of statements using ApplicativeDoStmt.  See
-- Note [ApplicativeDo].
rearrangeForApplicativeDo
  :: HsDoFlavour
  -> [(ExprLStmt GhcRn, FreeVars)]
  -> RnM ([ExprLStmt GhcRn], FreeVars)

rearrangeForApplicativeDo :: HsDoFlavour
-> [(ExprLStmt GhcRn, FreeVars)]
-> RnM ([ExprLStmt GhcRn], FreeVars)
rearrangeForApplicativeDo HsDoFlavour
_ [] = ([GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
 FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
      FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ([], FreeVars
emptyNameSet)
-- If the do-block contains a single @return@ statement, change it to
-- @pure@ if ApplicativeDo is turned on. See Note [ApplicativeDo].
rearrangeForApplicativeDo HsDoFlavour
ctxt [(ExprLStmt GhcRn
one,FreeVars
_)] = do
  (return_name, _) <- HsStmtContext Any -> Name -> RnM (Name, FreeVars)
forall fn. HsStmtContext fn -> Name -> RnM (Name, FreeVars)
lookupQualifiedDoName (HsDoFlavour -> HsStmtContext Any
forall fn. HsDoFlavour -> HsStmtContext fn
HsDoStmt HsDoFlavour
ctxt) Name
returnMName
  (pure_name, _)   <- lookupQualifiedDoName (HsDoStmt ctxt) pureAName
  let pure_expr = IdP GhcRn -> HsExpr GhcRn
forall (p :: Pass) a.
IsSrcSpanAnn p a =>
IdP (GhcPass p) -> HsExpr (GhcPass p)
nl_HsVar IdP GhcRn
Name
pure_name
  let monad_names = MonadNames { return_name :: Name
return_name = Name
return_name
                               , pure_name :: Name
pure_name   = Name
pure_name }
  return $ case needJoin monad_names [one] (Just pure_expr) of
    (Bool
False, [ExprLStmt GhcRn]
one') -> ([ExprLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
one', FreeVars
emptyNameSet)
    (Bool
True, [ExprLStmt GhcRn]
_) -> ([ExprLStmt GhcRn
GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
one], FreeVars
emptyNameSet)
rearrangeForApplicativeDo HsDoFlavour
ctxt [(ExprLStmt GhcRn, FreeVars)]
stmts0 = do
  optimal_ado <- GeneralFlag -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. GeneralFlag -> TcRnIf gbl lcl Bool
goptM GeneralFlag
Opt_OptimalApplicativeDo
  let stmt_tree | Bool
optimal_ado = [(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeOptimal [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts
                | Bool
otherwise = [(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeHeuristic [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts
  traceRn "rearrangeForADo" (ppr stmt_tree)
  (return_name, _) <- lookupQualifiedDoName (HsDoStmt ctxt) returnMName
  (pure_name, _)   <- lookupQualifiedDoName (HsDoStmt ctxt) pureAName
  let monad_names = MonadNames { return_name :: Name
return_name = Name
return_name
                               , pure_name :: Name
pure_name   = Name
pure_name }
  stmtTreeToStmts monad_names ctxt stmt_tree [last] last_fvs
  where
    ([(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts,(GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
last,FreeVars
last_fvs)) = [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> ([(GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)],
    (GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars))
forall {a}. [a] -> ([a], a)
findLast [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts0
    findLast :: [a] -> ([a], a)
findLast [] = String -> ([a], a)
forall a. HasCallStack => String -> a
error String
"findLast"
    findLast [a
last] = ([],a
last)
    findLast (a
x:[a]
xs) = (a
xa -> [a] -> [a]
forall a. a -> [a] -> [a]
:[a]
rest,a
last) where ([a]
rest,a
last) = [a] -> ([a], a)
findLast [a]
xs

-- | A tree of statements using a mixture of applicative and bind constructs.
data StmtTree a
  = StmtTreeOne a
  | StmtTreeBind (StmtTree a) (StmtTree a)
  | StmtTreeApplicative [StmtTree a]

instance Outputable a => Outputable (StmtTree a) where
  ppr :: StmtTree a -> SDoc
ppr (StmtTreeOne a
x)          = SDoc -> SDoc
forall doc. IsLine doc => doc -> doc
parens (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"StmtTreeOne" SDoc -> SDoc -> SDoc
forall doc. IsLine doc => doc -> doc -> doc
<+> a -> SDoc
forall a. Outputable a => a -> SDoc
ppr a
x)
  ppr (StmtTreeBind StmtTree a
x StmtTree a
y)       = SDoc -> SDoc
forall doc. IsLine doc => doc -> doc
parens (SDoc -> Int -> SDoc -> SDoc
hang (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"StmtTreeBind")
                                            Int
2 ([SDoc] -> SDoc
forall doc. IsLine doc => [doc] -> doc
sep [StmtTree a -> SDoc
forall a. Outputable a => a -> SDoc
ppr StmtTree a
x, StmtTree a -> SDoc
forall a. Outputable a => a -> SDoc
ppr StmtTree a
y]))
  ppr (StmtTreeApplicative [StmtTree a]
xs) = SDoc -> SDoc
forall doc. IsLine doc => doc -> doc
parens (SDoc -> Int -> SDoc -> SDoc
hang (String -> SDoc
forall doc. IsLine doc => String -> doc
text String
"StmtTreeApplicative")
                                            Int
2 ([SDoc] -> SDoc
forall doc. IsDoc doc => [doc] -> doc
vcat ((StmtTree a -> SDoc) -> [StmtTree a] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map StmtTree a -> SDoc
forall a. Outputable a => a -> SDoc
ppr [StmtTree a]
xs)))

flattenStmtTree :: StmtTree a -> [a]
flattenStmtTree :: forall a. StmtTree a -> [a]
flattenStmtTree StmtTree a
t = StmtTree a -> [a] -> [a]
forall {a}. StmtTree a -> [a] -> [a]
go StmtTree a
t []
 where
  go :: StmtTree a -> [a] -> [a]
go (StmtTreeOne a
a) [a]
as = a
a a -> [a] -> [a]
forall a. a -> [a] -> [a]
: [a]
as
  go (StmtTreeBind StmtTree a
l StmtTree a
r) [a]
as = StmtTree a -> [a] -> [a]
go StmtTree a
l (StmtTree a -> [a] -> [a]
go StmtTree a
r [a]
as)
  go (StmtTreeApplicative [StmtTree a]
ts) [a]
as = (StmtTree a -> [a] -> [a]) -> [a] -> [StmtTree a] -> [a]
forall a b. (a -> b -> b) -> b -> [a] -> b
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr StmtTree a -> [a] -> [a]
go [a]
as [StmtTree a]
ts

type ExprStmtTree = StmtTree (ExprLStmt GhcRn, FreeVars)
type Cost = Int

-- | Turn a sequence of statements into an ExprStmtTree using a
-- heuristic algorithm.  /O(n^2)/
mkStmtTreeHeuristic :: [(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeHeuristic :: [(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeHeuristic [(ExprLStmt GhcRn, FreeVars)
one] = (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (ExprLStmt GhcRn, FreeVars)
(GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
one
mkStmtTreeHeuristic [(ExprLStmt GhcRn, FreeVars)]
stmts =
  case [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
segments [(ExprLStmt GhcRn, FreeVars)]
stmts of
    [[(ExprLStmt GhcRn, FreeVars)]
one] -> [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
split [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
one
    [[(ExprLStmt GhcRn, FreeVars)]]
segs -> [StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. [StmtTree a] -> StmtTree a
StmtTreeApplicative (([(GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)]
 -> StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars))
-> [[(GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
-> [StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]
forall a b. (a -> b) -> [a] -> [b]
map [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
split [[(ExprLStmt GhcRn, FreeVars)]]
[[(GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)]]
segs)
 where
  split :: [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
split [(GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
one] = (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
one
  split [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts =
    StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. StmtTree a -> StmtTree a -> StmtTree a
StmtTreeBind ([(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeHeuristic [(ExprLStmt GhcRn, FreeVars)]
before) ([(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeHeuristic [(ExprLStmt GhcRn, FreeVars)]
after)
    where ([(ExprLStmt GhcRn, FreeVars)]
before, [(ExprLStmt GhcRn, FreeVars)]
after) = [(ExprLStmt GhcRn, FreeVars)]
-> ([(ExprLStmt GhcRn, FreeVars)], [(ExprLStmt GhcRn, FreeVars)])
splitSegment [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts

-- | Turn a sequence of statements into an ExprStmtTree optimally,
-- using dynamic programming.  /O(n^3)/
mkStmtTreeOptimal :: [(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeOptimal :: [(ExprLStmt GhcRn, FreeVars)] -> ExprStmtTree
mkStmtTreeOptimal [(ExprLStmt GhcRn, FreeVars)]
stmts =
  Bool -> ExprStmtTree -> ExprStmtTree
forall a. HasCallStack => Bool -> a -> a
assert (Bool -> Bool
not ([(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts)) (ExprStmtTree -> ExprStmtTree) -> ExprStmtTree -> ExprStmtTree
forall a b. (a -> b) -> a -> b
$ -- the empty case is handled by the caller;
                              -- we don't support empty StmtTrees.
  (StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars),
 Int)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a b. (a, b) -> a
fst (Array (Int, Int) (ExprStmtTree, Int)
Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
arr Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
-> (Int, Int)
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall i e. Ix i => Array i e -> i -> e
! (Int
0,Int
n))
  where
    n :: Int
n = [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> Int
forall a. [a] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
1
    stmt_arr :: Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr = (Int, Int)
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> Array
     Int
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall i e. Ix i => (i, i) -> [e] -> Array i e
listArray (Int
0,Int
n) [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts

    -- lazy cache of optimal trees for subsequences of the input
    arr :: Array (Int,Int) (ExprStmtTree, Cost)
    arr :: Array (Int, Int) (ExprStmtTree, Int)
arr = ((Int, Int), (Int, Int))
-> [((Int, Int),
     (StmtTree
        (GenLocated
           SrcSpanAnnA
           (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
         FreeVars),
      Int))]
-> Array
     (Int, Int)
     (StmtTree
        (GenLocated
           SrcSpanAnnA
           (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
         FreeVars),
      Int)
forall i e. Ix i => (i, i) -> [(i, e)] -> Array i e
array ((Int
0,Int
0),(Int
n,Int
n))
             [ ((Int
lo,Int
hi), Int
-> Int
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
tree Int
lo Int
hi)
             | Int
lo <- [Int
0..Int
n]
             , Int
hi <- [Int
lo..Int
n] ]

    -- compute the optimal tree for the sequence [lo..hi]
    tree :: Int
-> Int
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
tree Int
lo Int
hi
      | Int
hi Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
lo = ((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
lo), Int
1)
      | Bool
otherwise =
         case [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
segments [ Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
i | Int
i <- [Int
lo..Int
hi] ] of
           [] -> String
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall a. HasCallStack => String -> a
panic String
"mkStmtTree"
           [[(ExprLStmt GhcRn, FreeVars)]
_one] -> Int -> Int -> (ExprStmtTree, Int)
split Int
lo Int
hi
           [[(ExprLStmt GhcRn, FreeVars)]]
segs -> ([StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. [StmtTree a] -> StmtTree a
StmtTreeApplicative [StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]
trees, [Int] -> Int
forall a. Ord a => [a] -> a
forall (t :: * -> *) a. (Foldable t, Ord a) => t a -> a
maximum [Int]
costs)
             where
               bounds :: [(Int, Int)]
bounds = ((Int, Int)
 -> [(GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]
 -> (Int, Int))
-> (Int, Int)
-> [[(GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
-> [(Int, Int)]
forall b a. (b -> a -> b) -> b -> [a] -> [b]
scanl (\(Int
_,Int
hi) [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
a -> (Int
hiInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1, Int
hi Int -> Int -> Int
forall a. Num a => a -> a -> a
+ [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> Int
forall a. [a] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
a)) (Int
0,Int
loInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
1) [[(ExprLStmt GhcRn, FreeVars)]]
[[(GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)]]
segs
               ([StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]
trees,[Int]
costs) = [(StmtTree
    (GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars),
  Int)]
-> ([StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars)],
    [Int])
forall a b. [(a, b)] -> ([a], [b])
unzip (((Int, Int)
 -> (StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int))
-> [(Int, Int)]
-> [(StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int)]
forall a b. (a -> b) -> [a] -> [b]
map ((Int
 -> Int
 -> (StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int))
-> (Int, Int)
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall a b c. (a -> b -> c) -> (a, b) -> c
uncurry Int -> Int -> (ExprStmtTree, Int)
Int
-> Int
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
split) ([(Int, Int)] -> [(Int, Int)]
forall a. HasCallStack => [a] -> [a]
tail [(Int, Int)]
bounds))

    -- find the best place to split the segment [lo..hi]
    split :: Int -> Int -> (ExprStmtTree, Cost)
    split :: Int -> Int -> (ExprStmtTree, Int)
split Int
lo Int
hi
      | Int
hi Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
lo = ((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
lo), Int
1)
      | Bool
otherwise = (StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. StmtTree a -> StmtTree a -> StmtTree a
StmtTreeBind StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
before StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
after, Int
c1Int -> Int -> Int
forall a. Num a => a -> a -> a
+Int
c2)
        where
         -- As per the paper, for a sequence s1...sn, we want to find
         -- the split with the minimum cost, where the cost is the
         -- sum of the cost of the left and right subsequences.
         --
         -- As an optimisation (also in the paper) if the cost of
         -- s1..s(n-1) is different from the cost of s2..sn, we know
         -- that the optimal solution is the lower of the two.  Only
         -- in the case that these two have the same cost do we need
         -- to do the exhaustive search.
         --
         ((StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
before,Int
c1),(StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
after,Int
c2))
           | Int
hi Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
lo Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
1
           = (((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
lo), Int
1),
              ((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
hi), Int
1))
           | Int
left_cost Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
right_cost
           = ((StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
left,Int
left_cost), ((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
hi), Int
1))
           | Int
left_cost Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> Int
right_cost
           = (((GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
forall a. a -> StmtTree a
StmtTreeOne (Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
stmt_arr Array
  Int
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> Int
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
forall i e. Ix i => Array i e -> i -> e
! Int
lo), Int
1), (StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
right,Int
right_cost))
           | Bool
otherwise = (((StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int),
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int))
 -> ((StmtTree
        (GenLocated
           SrcSpanAnnA
           (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
         FreeVars),
      Int),
     (StmtTree
        (GenLocated
           SrcSpanAnnA
           (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
         FreeVars),
      Int))
 -> Ordering)
-> [((StmtTree
        (GenLocated
           SrcSpanAnnA
           (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
         FreeVars),
      Int),
     (StmtTree
        (GenLocated
           SrcSpanAnnA
           (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
         FreeVars),
      Int))]
-> ((StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int),
    (StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int))
forall (t :: * -> *) a.
Foldable t =>
(a -> a -> Ordering) -> t a -> a
minimumBy ((((StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int),
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int))
 -> Int)
-> ((StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int),
    (StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int))
-> ((StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int),
    (StmtTree
       (GenLocated
          SrcSpanAnnA
          (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
        FreeVars),
     Int))
-> Ordering
forall a b. Ord a => (b -> a) -> b -> b -> Ordering
comparing ((StmtTree
    (GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars),
  Int),
 (StmtTree
    (GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars),
  Int))
-> Int
forall {a} {a} {a}. Num a => ((a, a), (a, a)) -> a
cost) [((StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int),
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int))]
alternatives
           where
             (StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
left, Int
left_cost) = Array (Int, Int) (ExprStmtTree, Int)
Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
arr Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
-> (Int, Int)
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall i e. Ix i => Array i e -> i -> e
! (Int
lo,Int
hiInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
1)
             (StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
right, Int
right_cost) = Array (Int, Int) (ExprStmtTree, Int)
Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
arr Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
-> (Int, Int)
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall i e. Ix i => Array i e -> i -> e
! (Int
loInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1,Int
hi)
             cost :: ((a, a), (a, a)) -> a
cost ((a
_,a
c1),(a
_,a
c2)) = a
c1 a -> a -> a
forall a. Num a => a -> a -> a
+ a
c2
             alternatives :: [((StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int),
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int))]
alternatives = [ (Array (Int, Int) (ExprStmtTree, Int)
Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
arr Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
-> (Int, Int)
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall i e. Ix i => Array i e -> i -> e
! (Int
lo,Int
k), Array (Int, Int) (ExprStmtTree, Int)
Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
arr Array
  (Int, Int)
  (StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars),
   Int)
-> (Int, Int)
-> (StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars),
    Int)
forall i e. Ix i => Array i e -> i -> e
! (Int
kInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1,Int
hi))
                            | Int
k <- [Int
lo .. Int
hiInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
1] ]


-- | Turn the ExprStmtTree back into a sequence of statements, using
-- ApplicativeStmt where necessary.
stmtTreeToStmts
  :: MonadNames
  -> HsDoFlavour
  -> ExprStmtTree
  -> [ExprLStmt GhcRn]             -- ^ the "tail"
  -> FreeVars                     -- ^ free variables of the tail
  -> RnM ( [ExprLStmt GhcRn]       -- ( output statements,
         , FreeVars )             -- , things we needed

-- If we have a single bind, and we can do it without a join, transform
-- to an ApplicativeStmt.  This corresponds to the rule
--   dsBlock [pat <- rhs] (return expr) = expr <$> rhs
-- In the spec, but we do it here rather than in the desugarer,
-- because we need the typechecker to typecheck the <$> form rather than
-- the bind form, which would give rise to a Monad constraint.
--
-- If we have a single let, and the last statement is @return E@ or @return $ E@,
-- change the @return@ to @pure@.
stmtTreeToStmts :: MonadNames
-> HsDoFlavour
-> ExprStmtTree
-> [ExprLStmt GhcRn]
-> FreeVars
-> RnM ([ExprLStmt GhcRn], FreeVars)
stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt (StmtTreeOne (L SrcSpanAnnA
_ (BindStmt XBindStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
xbs LPat GhcRn
pat GenLocated SrcSpanAnnA (HsExpr GhcRn)
rhs), FreeVars
_))
                [ExprLStmt GhcRn]
tail FreeVars
_tail_fvs
  | Bool -> Bool
not (LPat GhcRn -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat GhcRn
pat), (Bool
False,[ExprLStmt GhcRn]
tail') <- MonadNames
-> [ExprLStmt GhcRn]
-> Maybe (HsExpr GhcRn)
-> (Bool, [ExprLStmt GhcRn])
needJoin MonadNames
monad_names [ExprLStmt GhcRn]
tail Maybe (HsExpr GhcRn)
forall a. Maybe a
Nothing
  -- See Note [ApplicativeDo and strict patterns]
  = HsDoFlavour
-> [ApplicativeArg GhcRn]
-> Bool
-> [ExprLStmt GhcRn]
-> RnM ([ExprLStmt GhcRn], FreeVars)
mkApplicativeStmt HsDoFlavour
ctxt [ApplicativeArgOne
                            { xarg_app_arg_one :: XApplicativeArgOne GhcRn
xarg_app_arg_one = XBindStmtRn -> Maybe (SyntaxExpr GhcRn)
xbsrn_failOp XBindStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
XBindStmtRn
xbs
                            , app_arg_pattern :: LPat GhcRn
app_arg_pattern  = LPat GhcRn
pat
                            , arg_expr :: XRec GhcRn (HsExpr GhcRn)
arg_expr         = XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
rhs
                            , is_body_stmt :: Bool
is_body_stmt     = Bool
False
                            }]
                      Bool
False [ExprLStmt GhcRn]
tail'
stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt (StmtTreeOne (L SrcSpanAnnA
_ (BodyStmt XBodyStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
_ GenLocated SrcSpanAnnA (HsExpr GhcRn)
rhs SyntaxExpr GhcRn
_ SyntaxExpr GhcRn
_),FreeVars
_))
                [ExprLStmt GhcRn]
tail FreeVars
_tail_fvs
  | (Bool
False,[ExprLStmt GhcRn]
tail') <- MonadNames
-> [ExprLStmt GhcRn]
-> Maybe (HsExpr GhcRn)
-> (Bool, [ExprLStmt GhcRn])
needJoin MonadNames
monad_names [ExprLStmt GhcRn]
tail Maybe (HsExpr GhcRn)
forall a. Maybe a
Nothing
  = HsDoFlavour
-> [ApplicativeArg GhcRn]
-> Bool
-> [ExprLStmt GhcRn]
-> RnM ([ExprLStmt GhcRn], FreeVars)
mkApplicativeStmt HsDoFlavour
ctxt
      [ApplicativeArgOne
       { xarg_app_arg_one :: XApplicativeArgOne GhcRn
xarg_app_arg_one = Maybe SyntaxExprRn
XApplicativeArgOne GhcRn
forall a. Maybe a
Nothing
       , app_arg_pattern :: LPat GhcRn
app_arg_pattern  = LPat GhcRn
nlWildPatName
       , arg_expr :: XRec GhcRn (HsExpr GhcRn)
arg_expr         = XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
rhs
       , is_body_stmt :: Bool
is_body_stmt     = Bool
True
       }] Bool
False [ExprLStmt GhcRn]
tail'
stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt (StmtTreeOne (let_stmt :: ExprLStmt GhcRn
let_stmt@(L SrcSpanAnnA
_ LetStmt{}),FreeVars
_))
                [ExprLStmt GhcRn]
tail FreeVars
_tail_fvs = do
  (pure_expr, _) <- HsStmtContext Any -> Name -> TcM (HsExpr GhcRn, FreeVars)
forall fn. HsStmtContext fn -> Name -> TcM (HsExpr GhcRn, FreeVars)
lookupQualifiedDoExpr (HsDoFlavour -> HsStmtContext Any
forall fn. HsDoFlavour -> HsStmtContext fn
HsDoStmt HsDoFlavour
ctxt) Name
pureAName
  return $ case needJoin monad_names tail (Just pure_expr) of
    (Bool
False, [ExprLStmt GhcRn]
tail') -> (ExprLStmt GhcRn
GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
let_stmt GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
forall a. a -> [a] -> [a]
: [ExprLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
tail', FreeVars
emptyNameSet)
    (Bool
True, [ExprLStmt GhcRn]
_) -> (ExprLStmt GhcRn
GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
let_stmt GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
forall a. a -> [a] -> [a]
: [ExprLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
tail, FreeVars
emptyNameSet)

stmtTreeToStmts MonadNames
_monad_names HsDoFlavour
_ctxt (StmtTreeOne (ExprLStmt GhcRn
s,FreeVars
_)) [ExprLStmt GhcRn]
tail FreeVars
_tail_fvs =
  ([GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
 FreeVars)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
      FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (ExprLStmt GhcRn
GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
s GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
-> [GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
forall a. a -> [a] -> [a]
: [ExprLStmt GhcRn]
[GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
tail, FreeVars
emptyNameSet)

stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt (StmtTreeBind ExprStmtTree
before ExprStmtTree
after) [ExprLStmt GhcRn]
tail FreeVars
tail_fvs = do
  (stmts1, fvs1) <- MonadNames
-> HsDoFlavour
-> ExprStmtTree
-> [ExprLStmt GhcRn]
-> FreeVars
-> RnM ([ExprLStmt GhcRn], FreeVars)
stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt ExprStmtTree
after [ExprLStmt GhcRn]
tail FreeVars
tail_fvs
  let tail1_fvs = [FreeVars] -> FreeVars
unionNameSets (FreeVars
tail_fvs FreeVars -> [FreeVars] -> [FreeVars]
forall a. a -> [a] -> [a]
: ((GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)
 -> FreeVars)
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [FreeVars]
forall a b. (a -> b) -> [a] -> [b]
map (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> FreeVars
forall a b. (a, b) -> b
snd (StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. StmtTree a -> [a]
flattenStmtTree ExprStmtTree
StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
after))
  (stmts2, fvs2) <- stmtTreeToStmts monad_names ctxt before stmts1 tail1_fvs
  return (stmts2, fvs1 `plusFV` fvs2)

stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt (StmtTreeApplicative [ExprStmtTree]
trees) [ExprLStmt GhcRn]
tail FreeVars
tail_fvs = do
   pairs <- (StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
 -> IOEnv (Env TcGblEnv TcLclEnv) (ApplicativeArg GhcRn, FreeVars))
-> [StmtTree
      (GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]
-> IOEnv (Env TcGblEnv TcLclEnv) [(ApplicativeArg GhcRn, FreeVars)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM (HsDoFlavour
-> FreeVars
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (ApplicativeArg GhcRn, FreeVars)
stmtTreeArg HsDoFlavour
ctxt FreeVars
tail_fvs) [ExprStmtTree]
[StmtTree
   (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]
trees
   dflags <- getDynFlags
   let (stmts', fvss) = unzip pairs
   let (need_join, tail') =
     -- See Note [ApplicativeDo and refutable patterns]
         if any (hasRefutablePattern dflags) stmts'
         then (True, tail)
         else needJoin monad_names tail Nothing

   (stmts, fvs) <- mkApplicativeStmt ctxt stmts' need_join tail'
   return (stmts, unionNameSets (fvs:fvss))
 where
   stmtTreeArg :: HsDoFlavour
-> FreeVars
-> StmtTree
     (GenLocated
        SrcSpanAnnA
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (ApplicativeArg GhcRn, FreeVars)
stmtTreeArg HsDoFlavour
_ctxt FreeVars
_tail_fvs (StmtTreeOne (L SrcSpanAnnA
_ (BindStmt XBindStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
xbs LPat GhcRn
pat GenLocated SrcSpanAnnA (HsExpr GhcRn)
exp), FreeVars
_))
     = (ApplicativeArg GhcRn, FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (ApplicativeArg GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (ApplicativeArgOne
               { xarg_app_arg_one :: XApplicativeArgOne GhcRn
xarg_app_arg_one = XBindStmtRn -> Maybe (SyntaxExpr GhcRn)
xbsrn_failOp XBindStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
XBindStmtRn
xbs
               , app_arg_pattern :: LPat GhcRn
app_arg_pattern  = LPat GhcRn
pat
               , arg_expr :: XRec GhcRn (HsExpr GhcRn)
arg_expr         = XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
exp
               , is_body_stmt :: Bool
is_body_stmt     = Bool
False
               }, FreeVars
emptyFVs)
   stmtTreeArg HsDoFlavour
_ctxt FreeVars
_tail_fvs (StmtTreeOne (L SrcSpanAnnA
_ (BodyStmt XBodyStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
_ GenLocated SrcSpanAnnA (HsExpr GhcRn)
exp SyntaxExpr GhcRn
_ SyntaxExpr GhcRn
_), FreeVars
_)) =
     (ApplicativeArg GhcRn, FreeVars)
-> IOEnv (Env TcGblEnv TcLclEnv) (ApplicativeArg GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (ApplicativeArgOne
             { xarg_app_arg_one :: XApplicativeArgOne GhcRn
xarg_app_arg_one = Maybe SyntaxExprRn
XApplicativeArgOne GhcRn
forall a. Maybe a
Nothing
             , app_arg_pattern :: LPat GhcRn
app_arg_pattern  = LPat GhcRn
nlWildPatName
             , arg_expr :: XRec GhcRn (HsExpr GhcRn)
arg_expr         = XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
exp
             , is_body_stmt :: Bool
is_body_stmt     = Bool
True
             }, FreeVars
emptyFVs)
   stmtTreeArg HsDoFlavour
ctxt FreeVars
tail_fvs StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
tree = do
     let stmts :: [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts = StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. StmtTree a -> [a]
flattenStmtTree StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
tree
         pvarset :: FreeVars
pvarset = [Name] -> FreeVars
mkNameSet (((GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)
 -> [Name])
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap (CollectFlag GhcRn
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> [IdP GhcRn]
forall (idL :: Pass) (idR :: Pass) body.
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> StmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)]
collectStmtBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
 -> [Name])
-> ((GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)
    -> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
-> [Name]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
 -> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> ((GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)
    -> GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
forall a b. (a, b) -> a
fst) [(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts)
                     FreeVars -> FreeVars -> FreeVars
`intersectNameSet` FreeVars
tail_fvs
         pvars :: [Name]
pvars = FreeVars -> [Name]
nameSetElemsStable FreeVars
pvarset
           -- See Note [Deterministic ApplicativeDo and RecursiveDo desugaring]
         pat :: LPat GhcRn
pat = [IdP GhcRn] -> LPat GhcRn
mkBigLHsVarPatTup [IdP GhcRn]
[Name]
pvars
         tup :: XRec GhcRn (HsExpr GhcRn)
tup = [IdP GhcRn] -> XExplicitTuple GhcRn -> XRec GhcRn (HsExpr GhcRn)
forall (p :: Pass) a.
IsSrcSpanAnn p a =>
[IdP (GhcPass p)]
-> XExplicitTuple (GhcPass p) -> LHsExpr (GhcPass p)
mkBigLHsVarTup [IdP GhcRn]
[Name]
pvars XExplicitTuple GhcRn
NoExtField
noExtField
     (stmts',fvs2) <- MonadNames
-> HsDoFlavour
-> ExprStmtTree
-> [ExprLStmt GhcRn]
-> FreeVars
-> RnM ([ExprLStmt GhcRn], FreeVars)
stmtTreeToStmts MonadNames
monad_names HsDoFlavour
ctxt ExprStmtTree
StmtTree
  (GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)
tree [] FreeVars
pvarset
     (mb_ret, fvs1) <-
        if | L _ ApplicativeStmt{} <- last stmts' ->
             return (unLoc tup, emptyNameSet)
           | otherwise -> do
             -- Need 'pureAName' and not 'returnMName' here, so that it requires
             -- 'Applicative' and not 'Monad' whenever possible (until #20540 is fixed).
             (ret, _) <- lookupQualifiedDoExpr (HsDoStmt ctxt) pureAName
             let expr = XApp GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XApp p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsApp XApp GhcRn
NoExtField
noExtField (HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall e a. HasAnnotation e => a -> GenLocated e a
noLocA HsExpr GhcRn
ret) XRec GhcRn (HsExpr GhcRn)
tup
             return (expr, emptyFVs)
     return ( ApplicativeArgMany
              { xarg_app_arg_many = noExtField
              , app_stmts         = stmts'
              , final_expr        = mb_ret
              , bv_pattern        = pat
              , stmt_context      = ctxt
              }
            , fvs1 `plusFV` fvs2)


-- | Divide a sequence of statements into segments, where no segment
-- depends on any variables defined by a statement in another segment.
segments
  :: [(ExprLStmt GhcRn, FreeVars)]
  -> [[(ExprLStmt GhcRn, FreeVars)]]
segments :: [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
segments [(ExprLStmt GhcRn, FreeVars)]
stmts = [[(GenLocated
     (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall {a :: Pass} {b} {b}.
[[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
merge ([[(GenLocated
      (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]]
 -> [[(GenLocated
         (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]])
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall a b. (a -> b) -> a -> b
$ [[(GenLocated
     (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall a. [a] -> [a]
reverse ([[(GenLocated
      (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)]]
 -> [[(GenLocated
         (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]])
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall a b. (a -> b) -> a -> b
$ ([(ExprLStmt GhcRn, FreeVars)]
 -> [(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)])
-> [[(ExprLStmt GhcRn, FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall a b. (a -> b) -> [a] -> [b]
map [(ExprLStmt GhcRn, FreeVars)]
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. [a] -> [a]
reverse ([[(ExprLStmt GhcRn, FreeVars)]]
 -> [[(GenLocated
         (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]])
-> [[(ExprLStmt GhcRn, FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall a b. (a -> b) -> a -> b
$ [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
walk ([(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. [a] -> [a]
reverse [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts)
  where
    allvars :: FreeVars
allvars = [Name] -> FreeVars
mkNameSet (((GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)
 -> [Name])
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap (CollectFlag GhcRn
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> [IdP GhcRn]
forall (idL :: Pass) (idR :: Pass) body.
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> StmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)]
collectStmtBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
 -> [Name])
-> ((GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)
    -> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
-> [Name]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated
  SrcSpanAnnA
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
 -> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> ((GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)
    -> GenLocated
         SrcSpanAnnA
         (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
-> (GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
    FreeVars)
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (GenLocated
   SrcSpanAnnA
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
forall a b. (a, b) -> a
fst) [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts)

    -- We would rather not have a segment that just has LetStmts in
    -- it, so combine those with the next segment where possible.
    -- We don't merge it with the previous segment because the merged segment
    -- would require 'Monad' while it may otherwise only require 'Applicative'.
    merge :: [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
merge [] = []
    merge ([(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
seg : [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
segs)
       = case [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
rest of
          [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
s:[[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
ss | Bool
all_lets -> ([(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
seg [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
-> [(GenLocated
       (Anno (StmtLR (GhcPass a) (GhcPass a) b))
       (StmtLR (GhcPass a) (GhcPass a) b),
     b)]
-> [(GenLocated
       (Anno (StmtLR (GhcPass a) (GhcPass a) b))
       (StmtLR (GhcPass a) (GhcPass a) b),
     b)]
forall a. [a] -> [a] -> [a]
++ [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
s) [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
forall a. a -> [a] -> [a]
: [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
ss
          [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
_otherwise -> [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
seg [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
forall a. a -> [a] -> [a]
: [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
rest
      where
        rest :: [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
rest = [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
-> [[(GenLocated
        (Anno (StmtLR (GhcPass a) (GhcPass a) b))
        (StmtLR (GhcPass a) (GhcPass a) b),
      b)]]
merge [[(GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b),
   b)]]
segs
        all_lets :: Bool
all_lets = ((GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)
 -> Bool)
-> [(GenLocated
       (Anno (StmtLR (GhcPass a) (GhcPass a) b))
       (StmtLR (GhcPass a) (GhcPass a) b),
     b)]
-> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
all (LStmt (GhcPass a) b -> Bool
GenLocated
  (Anno (StmtLR (GhcPass a) (GhcPass a) b))
  (StmtLR (GhcPass a) (GhcPass a) b)
-> Bool
forall (a :: Pass) b. LStmt (GhcPass a) b -> Bool
isLetStmt (GenLocated
   (Anno (StmtLR (GhcPass a) (GhcPass a) b))
   (StmtLR (GhcPass a) (GhcPass a) b)
 -> Bool)
-> ((GenLocated
       (Anno (StmtLR (GhcPass a) (GhcPass a) b))
       (StmtLR (GhcPass a) (GhcPass a) b),
     b)
    -> GenLocated
         (Anno (StmtLR (GhcPass a) (GhcPass a) b))
         (StmtLR (GhcPass a) (GhcPass a) b))
-> (GenLocated
      (Anno (StmtLR (GhcPass a) (GhcPass a) b))
      (StmtLR (GhcPass a) (GhcPass a) b),
    b)
-> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (GenLocated
   (Anno (StmtLR (GhcPass a) (GhcPass a) b))
   (StmtLR (GhcPass a) (GhcPass a) b),
 b)
-> GenLocated
     (Anno (StmtLR (GhcPass a) (GhcPass a) b))
     (StmtLR (GhcPass a) (GhcPass a) b)
forall a b. (a, b) -> a
fst) [(GenLocated
    (Anno (StmtLR (GhcPass a) (GhcPass a) b))
    (StmtLR (GhcPass a) (GhcPass a) b),
  b)]
seg

    -- walk splits the statement sequence into segments, traversing
    -- the sequence from the back to the front, and keeping track of
    -- the set of free variables of the current segment.  Whenever
    -- this set of free variables is empty, we have a complete segment.
    walk :: [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
    walk :: [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
walk [] = []
    walk ((ExprLStmt GhcRn
stmt,FreeVars
fvs) : [(ExprLStmt GhcRn, FreeVars)]
stmts) = ((ExprLStmt GhcRn
GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt,FreeVars
fvs) (GenLocated
   (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. a -> [a] -> [a]
: [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
seg) [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
-> [[(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)]]
forall a. a -> [a] -> [a]
: [(ExprLStmt GhcRn, FreeVars)] -> [[(ExprLStmt GhcRn, FreeVars)]]
walk [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest
      where ([(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
seg,[(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest) = FreeVars
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> ([(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)],
    [(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)])
chunter FreeVars
fvs' [(ExprLStmt GhcRn, FreeVars)]
[(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
stmts
            (FreeVars
_, FreeVars
fvs') = GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> FreeVars -> (FreeVars, FreeVars)
stmtRefs ExprLStmt GhcRn
GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt FreeVars
fvs

    chunter :: FreeVars
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> ([(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)],
    [(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)])
chunter FreeVars
_ [] = ([], [])
    chunter FreeVars
vars ((GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt,FreeVars
fvs) : [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest)
       | Bool -> Bool
not (FreeVars -> Bool
isEmptyNameSet FreeVars
vars)
       Bool -> Bool -> Bool
|| ExprLStmt GhcRn -> Bool
isStrictPatternBind ExprLStmt GhcRn
GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt
           -- See Note [ApplicativeDo and strict patterns]
       = ((GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt,FreeVars
fvs) (GenLocated
   (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
   (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
 FreeVars)
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. a -> [a] -> [a]
: [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
chunk, [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest')
       where ([(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
chunk,[(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest') = FreeVars
-> [(GenLocated
       (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> ([(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)],
    [(GenLocated
        (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
        (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)])
chunter FreeVars
vars' [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest
             (FreeVars
pvars, FreeVars
evars) = GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> FreeVars -> (FreeVars, FreeVars)
stmtRefs GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt FreeVars
fvs
             vars' :: FreeVars
vars' = (FreeVars
vars FreeVars -> FreeVars -> FreeVars
`minusNameSet` FreeVars
pvars) FreeVars -> FreeVars -> FreeVars
`unionNameSet` FreeVars
evars
    chunter FreeVars
_ [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest = ([], [(GenLocated
    (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest)

    stmtRefs :: GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> FreeVars -> (FreeVars, FreeVars)
stmtRefs GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt FreeVars
fvs
      | LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)) -> Bool
forall (a :: Pass) b. LStmt (GhcPass a) b -> Bool
isLetStmt LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt = (FreeVars
pvars, FreeVars
fvs' FreeVars -> FreeVars -> FreeVars
`minusNameSet` FreeVars
pvars)
      | Bool
otherwise      = (FreeVars
pvars, FreeVars
fvs')
      where fvs' :: FreeVars
fvs' = FreeVars
fvs FreeVars -> FreeVars -> FreeVars
`intersectNameSet` FreeVars
allvars
            pvars :: FreeVars
pvars = [Name] -> FreeVars
mkNameSet (CollectFlag GhcRn
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> [IdP GhcRn]
forall (idL :: Pass) (idR :: Pass) body.
CollectPass (GhcPass idL) =>
CollectFlag (GhcPass idL)
-> StmtLR (GhcPass idL) (GhcPass idR) body -> [IdP (GhcPass idL)]
collectStmtBinders CollectFlag GhcRn
forall p. CollectFlag p
CollNoDictBinders (GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc GenLocated
  (Anno (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
  (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
stmt))

    isStrictPatternBind :: ExprLStmt GhcRn -> Bool
    isStrictPatternBind :: ExprLStmt GhcRn -> Bool
isStrictPatternBind (L SrcSpanAnnA
_ (BindStmt XBindStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
_ LPat GhcRn
pat GenLocated SrcSpanAnnA (HsExpr GhcRn)
_)) = LPat GhcRn -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat GhcRn
pat
    isStrictPatternBind ExprLStmt GhcRn
_ = Bool
False

{-
Note [ApplicativeDo and strict patterns]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A strict pattern match is really a dependency.  For example,

do
  (x,y) <- A
  z <- B
  return C

The pattern (_,_) must be matched strictly before we do B.  If we
allowed this to be transformed into

  (\(x,y) -> \z -> C) <$> A <*> B

then it could be lazier than the standard desugaring using >>=.  See #13875
for more examples.

Thus, whenever we have a strict pattern match, we treat it as a
dependency between that statement and the following one.  The
dependency prevents those two statements from being performed "in
parallel" in an ApplicativeStmt, but doesn't otherwise affect what we
can do with the rest of the statements in the same "do" expression.
-}

isStrictPattern :: forall p. IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern :: forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern (L SrcSpanAnnA
loc Pat (GhcPass p)
pat) =
  case Pat (GhcPass p)
pat of
    WildPat{}       -> Bool
False
    VarPat{}        -> Bool
False
    LazyPat{}       -> Bool
False
    AsPat XAsPat (GhcPass p)
_ LIdP (GhcPass p)
_ LPat (GhcPass p)
p     -> LPat (GhcPass p) -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat (GhcPass p)
p
    ParPat XParPat (GhcPass p)
_ LPat (GhcPass p)
p      -> LPat (GhcPass p) -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat (GhcPass p)
p
    ViewPat XViewPat (GhcPass p)
_ LHsExpr (GhcPass p)
_ LPat (GhcPass p)
p   -> LPat (GhcPass p) -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat (GhcPass p)
p
    SigPat XSigPat (GhcPass p)
_ LPat (GhcPass p)
p HsPatSigType (NoGhcTc (GhcPass p))
_    -> LPat (GhcPass p) -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat (GhcPass p)
p
    BangPat{}       -> Bool
True
    ListPat{}       -> Bool
True
    TuplePat{}      -> Bool
True
    SumPat{}        -> Bool
True
    ConPat{}        -> Bool
True
    LitPat{}        -> Bool
True
    NPat{}          -> Bool
True
    NPlusKPat{}     -> Bool
True
    SplicePat{}     -> Bool
True

    -- The behavior of this case is unimportant, as GHC will throw an error shortly
    -- after reaching this case for other reasons (see TcRnIllegalTypePattern).
    EmbTyPat{}  -> Bool
False
    InvisPat{}  -> Bool
False

    XPat XXPat (GhcPass p)
ext        -> case forall (p :: Pass). IsPass p => GhcPass p
ghcPass @p of
      GhcPass p
GhcRn
        | HsPatExpanded Pat GhcRn
_ Pat GhcRn
p <- XXPat (GhcPass p)
ext
        -> LPat GhcRn -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern (SrcSpanAnnA -> Pat GhcRn -> GenLocated SrcSpanAnnA (Pat GhcRn)
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc Pat GhcRn
p)
      GhcPass p
GhcTc -> case XXPat (GhcPass p)
ext of
        ExpansionPat Pat GhcRn
_ Pat GhcTc
p -> LPat GhcTc -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern (SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc Pat GhcTc
p)
        CoPat {} -> String -> Bool
forall a. HasCallStack => String -> a
panic String
"isStrictPattern: CoPat"

{-
Note [ApplicativeDo and refutable patterns]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Refutable patterns in do blocks are desugared to use the monadic 'fail' operation.
This means that sometimes an applicative block needs to be wrapped in 'join' simply because
of a refutable pattern, in order for the types to work out.

-}

hasRefutablePattern :: DynFlags -> ApplicativeArg GhcRn -> Bool
hasRefutablePattern :: DynFlags -> ApplicativeArg GhcRn -> Bool
hasRefutablePattern DynFlags
dflags (ApplicativeArgOne { app_arg_pattern :: forall idL. ApplicativeArg idL -> LPat idL
app_arg_pattern = LPat GhcRn
pat
                                              , is_body_stmt :: forall idL. ApplicativeArg idL -> Bool
is_body_stmt = Bool
False}) =
                                         Bool -> Bool
not (DynFlags -> LPat GhcRn -> Bool
forall (p :: Pass).
OutputableBndrId p =>
DynFlags -> LPat (GhcPass p) -> Bool
isIrrefutableHsPat DynFlags
dflags LPat GhcRn
pat)
hasRefutablePattern DynFlags
_ ApplicativeArg GhcRn
_ = Bool
False

isLetStmt :: LStmt (GhcPass a) b -> Bool
isLetStmt :: forall (a :: Pass) b. LStmt (GhcPass a) b -> Bool
isLetStmt (L Anno (StmtLR (GhcPass a) (GhcPass a) b)
_ LetStmt{}) = Bool
True
isLetStmt LStmt (GhcPass a) b
_ = Bool
False

-- | Find a "good" place to insert a bind in an indivisible segment.
-- This is the only place where we use heuristics.  The current
-- heuristic is to peel off the first group of independent statements
-- and put the bind after those.
splitSegment
  :: [(ExprLStmt GhcRn, FreeVars)]
  -> ( [(ExprLStmt GhcRn, FreeVars)]
     , [(ExprLStmt GhcRn, FreeVars)] )
splitSegment :: [(ExprLStmt GhcRn, FreeVars)]
-> ([(ExprLStmt GhcRn, FreeVars)], [(ExprLStmt GhcRn, FreeVars)])
splitSegment [(ExprLStmt GhcRn, FreeVars)
one,(ExprLStmt GhcRn, FreeVars)
two] = ([(ExprLStmt GhcRn, FreeVars)
one],[(ExprLStmt GhcRn, FreeVars)
two])
  -- there is no choice when there are only two statements; this just saves
  -- some work in a common case.
splitSegment [(ExprLStmt GhcRn, FreeVars)]
stmts
  | Just ([(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
lets,[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
binds,[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
rest) <- [(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
-> Maybe
     ([(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)],
      [(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)],
      [(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)])
forall (body :: * -> *).
[(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
-> Maybe
     ([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)],
      [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)],
      [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)])
slurpIndependentStmts [(ExprLStmt GhcRn, FreeVars)]
[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
stmts
  =  if Bool -> Bool
not ([(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
lets)
       then ([(ExprLStmt GhcRn, FreeVars)]
[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
lets, [(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
binds[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. [a] -> [a] -> [a]
++[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
rest)
       else ([(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
lets[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
-> [(GenLocated
       SrcSpanAnnA
       (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
     FreeVars)]
forall a. [a] -> [a] -> [a]
++[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA
    (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
binds, [(ExprLStmt GhcRn, FreeVars)]
[(LStmt GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)), FreeVars)]
rest)
  | Bool
otherwise
  = case [(ExprLStmt GhcRn, FreeVars)]
stmts of
      ((ExprLStmt GhcRn, FreeVars)
x:[(ExprLStmt GhcRn, FreeVars)]
xs) -> ([(ExprLStmt GhcRn, FreeVars)
x],[(ExprLStmt GhcRn, FreeVars)]
xs)
      [(ExprLStmt GhcRn, FreeVars)]
_other -> ([(ExprLStmt GhcRn, FreeVars)]
stmts,[])

slurpIndependentStmts
   :: [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
   -> Maybe ( [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)] -- LetStmts
            , [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)] -- BindStmts
            , [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)] )
slurpIndependentStmts :: forall (body :: * -> *).
[(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
-> Maybe
     ([(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)],
      [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)],
      [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)])
slurpIndependentStmts [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
stmts = [(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
  FreeVars)]
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
     FreeVars)]
-> FreeVars
-> [(GenLocated
       SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
     FreeVars)]
-> Maybe
     ([(GenLocated
          SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
        FreeVars)],
      [(GenLocated
          SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
        FreeVars)],
      [(GenLocated
          SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
        FreeVars)])
forall {p :: Pass} {idR} {body} {idR} {body} {l}.
(XBindStmt (GhcPass p) idR body ~ XBindStmt (GhcPass p) idR body,
 IdGhcP p ~ Name,
 XLetStmt (GhcPass p) idR body ~ XLetStmt (GhcPass p) idR body,
 IsPass p) =>
[(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> FreeVars
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> Maybe
     ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
go [] [] FreeVars
emptyNameSet [(LStmt GhcRn (LocatedA (body GhcRn)), FreeVars)]
[(GenLocated
    SrcSpanAnnA (StmtLR GhcRn GhcRn (LocatedA (body GhcRn))),
  FreeVars)]
stmts
 where
  -- If we encounter a BindStmt that doesn't depend on a previous BindStmt
  -- in this group, then add it to the group. We have to be careful about
  -- strict patterns though; splitSegments expects that if we return Just
  -- then we have actually done some splitting. Otherwise it will go into
  -- an infinite loop (#14163).
  go :: [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> FreeVars
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> Maybe
     ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
go [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
lets [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
indep FreeVars
bndrs ((L l
loc (BindStmt XBindStmt (GhcPass p) idR body
xbs LPat (GhcPass p)
pat body
body), FreeVars
fvs): [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
rest)
    | FreeVars -> FreeVars -> Bool
disjointNameSet FreeVars
bndrs FreeVars
fvs Bool -> Bool -> Bool
&& Bool -> Bool
not (LPat (GhcPass p) -> Bool
forall (p :: Pass). IsPass p => LPat (GhcPass p) -> Bool
isStrictPattern LPat (GhcPass p)
pat)
    = [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> FreeVars
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> Maybe
     ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
go [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
lets ((l
-> StmtLR (GhcPass p) idR body
-> GenLocated l (StmtLR (GhcPass p) idR body)
forall l e. l -> e -> GenLocated l e
L l
loc (XBindStmt (GhcPass p) idR body
-> LPat (GhcPass p) -> body -> StmtLR (GhcPass p) idR body
forall idL idR body.
XBindStmt idL idR body -> LPat idL -> body -> StmtLR idL idR body
BindStmt XBindStmt (GhcPass p) idR body
XBindStmt (GhcPass p) idR body
xbs LPat (GhcPass p)
pat body
body), FreeVars
fvs) (GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
forall a. a -> [a] -> [a]
: [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
indep)
         FreeVars
bndrs' [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
rest
    where bndrs' :: FreeVars
bndrs' = FreeVars
bndrs FreeVars -> FreeVars -> FreeVars
`unionNameSet` [Name] -> FreeVars
mkNameSet (CollectFlag (GhcPass p) -> LPat (GhcPass p) -> [IdP (GhcPass p)]
forall p. CollectPass p => CollectFlag p -> LPat p -> [IdP p]
collectPatBinders CollectFlag (GhcPass p)
forall p. CollectFlag p
CollNoDictBinders LPat (GhcPass p)
pat)
  -- If we encounter a LetStmt that doesn't depend on a BindStmt in this
  -- group, then move it to the beginning, so that it doesn't interfere with
  -- grouping more BindStmts.
  -- TODO: perhaps we shouldn't do this if there are any strict bindings,
  -- because we might be moving evaluation earlier.
  go [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
lets [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
indep FreeVars
bndrs ((L l
loc (LetStmt XLetStmt (GhcPass p) idR body
noExtField HsLocalBindsLR (GhcPass p) idR
binds), FreeVars
fvs) : [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
rest)
    | FreeVars -> FreeVars -> Bool
disjointNameSet FreeVars
bndrs FreeVars
fvs
    = [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> FreeVars
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> Maybe
     ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
go ((l
-> StmtLR (GhcPass p) idR body
-> GenLocated l (StmtLR (GhcPass p) idR body)
forall l e. l -> e -> GenLocated l e
L l
loc (XLetStmt (GhcPass p) idR body
-> HsLocalBindsLR (GhcPass p) idR -> StmtLR (GhcPass p) idR body
forall idL idR body.
XLetStmt idL idR body
-> HsLocalBindsLR idL idR -> StmtLR idL idR body
LetStmt XLetStmt (GhcPass p) idR body
XLetStmt (GhcPass p) idR body
noExtField HsLocalBindsLR (GhcPass p) idR
binds), FreeVars
fvs) (GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
forall a. a -> [a] -> [a]
: [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
lets) [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
indep FreeVars
bndrs [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
rest
  go [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
_ []  FreeVars
_ [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
_ = Maybe
  ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
   [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
   [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
forall a. Maybe a
Nothing
  go [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
_ [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)
_] FreeVars
_ [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
_ = Maybe
  ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
   [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
   [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
forall a. Maybe a
Nothing
  go [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
lets [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
indep FreeVars
_ [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
stmts = ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
 [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
 [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
-> Maybe
     ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)],
      [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)])
forall a. a -> Maybe a
Just ([(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
forall a. [a] -> [a]
reverse [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
lets, [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
-> [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
forall a. [a] -> [a]
reverse [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
indep, [(GenLocated l (StmtLR (GhcPass p) idR body), FreeVars)]
stmts)

-- | Build an ApplicativeStmt, and strip the "return" from the tail
-- if necessary.
--
-- For example, if we start with
--   do x <- E1; y <- E2; return (f x y)
-- then we get
--   do (E1[x] | E2[y]); f x y
--
-- the LastStmt in this case has the return removed, but we set the
-- flag on the LastStmt to indicate this, so that we can print out the
-- original statement correctly in error messages.  It is easier to do
-- it this way rather than try to ignore the return later in both the
-- typechecker and the desugarer (I tried it that way first!).
mkApplicativeStmt
  :: HsDoFlavour
  -> [ApplicativeArg GhcRn]             -- ^ The args
  -> Bool                               -- ^ True <=> need a join
  -> [ExprLStmt GhcRn]        -- ^ The body statements
  -> RnM ([ExprLStmt GhcRn], FreeVars)
mkApplicativeStmt :: HsDoFlavour
-> [ApplicativeArg GhcRn]
-> Bool
-> [ExprLStmt GhcRn]
-> RnM ([ExprLStmt GhcRn], FreeVars)
mkApplicativeStmt HsDoFlavour
ctxt [ApplicativeArg GhcRn]
args Bool
need_join [ExprLStmt GhcRn]
body_stmts
  = do { (fmap_op, fvs1) <- HsStmtContextRn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupQualifiedDoStmtName (HsDoFlavour -> HsStmtContext (GenLocated SrcSpanAnnN Name)
forall fn. HsDoFlavour -> HsStmtContext fn
HsDoStmt HsDoFlavour
ctxt) Name
fmapName
       ; (ap_op, fvs2) <- lookupQualifiedDoStmtName (HsDoStmt ctxt) apAName
       ; (mb_join, fvs3) <-
           if need_join then
             do { (join_op, fvs) <- lookupQualifiedDoStmtName (HsDoStmt ctxt) joinMName
                ; return (Just join_op, fvs) }
           else
             return (Nothing, emptyNameSet)
       -- We cannot really say where the ApplicativeStmt is located with more accuracy
       -- than the span of the do-block, but it is better than nothing for IDE info
       -- See Note [Source locations for implicit function calls]
       ; loc <- getSrcSpanM
       ; let applicative_stmt = SrcSpanAnnA
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
forall l e. l -> e -> GenLocated l e
L (SrcSpan -> SrcSpanAnnA
forall e. HasAnnotation e => SrcSpan -> e
noAnnSrcSpan SrcSpan
loc) (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
 -> GenLocated
      SrcSpanAnnA
      (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))))
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
forall a b. (a -> b) -> a -> b
$ XApplicativeStmt
  GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> [(SyntaxExpr GhcRn, ApplicativeArg GhcRn)]
-> Maybe (SyntaxExpr GhcRn)
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall idL idR body.
XApplicativeStmt idL idR body
-> [(SyntaxExpr idR, ApplicativeArg idL)]
-> Maybe (SyntaxExpr idR)
-> StmtLR idL idR body
ApplicativeStmt XApplicativeStmt
  GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
NoExtField
noExtField
               ([SyntaxExprRn]
-> [ApplicativeArg GhcRn] -> [(SyntaxExprRn, ApplicativeArg GhcRn)]
forall a b. [a] -> [b] -> [(a, b)]
zip (SyntaxExprRn
fmap_op SyntaxExprRn -> [SyntaxExprRn] -> [SyntaxExprRn]
forall a. a -> [a] -> [a]
: SyntaxExprRn -> [SyntaxExprRn]
forall a. a -> [a]
repeat SyntaxExprRn
ap_op) [ApplicativeArg GhcRn]
args)
               Maybe (SyntaxExpr GhcRn)
Maybe SyntaxExprRn
mb_join
       ; return ( applicative_stmt : body_stmts
                , fvs1 `plusFV` fvs2 `plusFV` fvs3) }

-- | Given the statements following an ApplicativeStmt, determine whether
-- we need a @join@ or not, and remove the @return@ if necessary.
--
-- We don't need @join@ if there's a single @LastStmt@ in the form of
-- @return E@, @return $ E@, @pure E@ or @pure $ E@.
needJoin :: MonadNames
         -> [ExprLStmt GhcRn]
            -- If this is @Just pure@, replace return by pure
            -- If this is @Nothing@, strip the return/pure
         -> Maybe (HsExpr GhcRn)
         -> (Bool, [ExprLStmt GhcRn])
needJoin :: MonadNames
-> [ExprLStmt GhcRn]
-> Maybe (HsExpr GhcRn)
-> (Bool, [ExprLStmt GhcRn])
needJoin MonadNames
_monad_names [] Maybe (HsExpr GhcRn)
_mb_pure = (Bool
False, [])  -- we're in an ApplicativeArg
needJoin MonadNames
monad_names  [L SrcSpanAnnA
loc (LastStmt XLastStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
_ GenLocated SrcSpanAnnA (HsExpr GhcRn)
e Maybe Bool
_ SyntaxExpr GhcRn
t)] Maybe (HsExpr GhcRn)
mb_pure
 | Just (XRec GhcRn (HsExpr GhcRn)
arg, Maybe Bool
noret) <- MonadNames
-> XRec GhcRn (HsExpr GhcRn)
-> Maybe (HsExpr GhcRn)
-> Maybe (XRec GhcRn (HsExpr GhcRn), Maybe Bool)
isReturnApp MonadNames
monad_names XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
e Maybe (HsExpr GhcRn)
mb_pure =
       (Bool
False, [SrcSpanAnnA
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> GenLocated
     SrcSpanAnnA
     (StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc (XLastStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> Maybe Bool
-> SyntaxExpr GhcRn
-> StmtLR GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
forall idL idR body.
XLastStmt idL idR body
-> body -> Maybe Bool -> SyntaxExpr idR -> StmtLR idL idR body
LastStmt XLastStmt GhcRn GhcRn (GenLocated SrcSpanAnnA (HsExpr GhcRn))
NoExtField
noExtField XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
arg Maybe Bool
noret SyntaxExpr GhcRn
t)])
needJoin MonadNames
_monad_names [ExprLStmt GhcRn]
stmts Maybe (HsExpr GhcRn)
_mb_pure = (Bool
True, [ExprLStmt GhcRn]
stmts)

-- | @(Just e, Just False)@, if the expression is @return/pure e@,
--     and the third argument is Nothing,
--   @(Just e, Just True)@ if the expression is @return/pure $ e@,
--     and the third argument is Nothing,
--   @(Just (pure e), Nothing)@ if the expression is @return/pure e@,
--     and the third argument is @Just pure_expr@,
--   @(Just (pure $ e), Nothing)@ if the expression is @return/pure $ e@,
--     and the third argument is @Just pure_expr@,
--   otherwise @Nothing@.
isReturnApp :: MonadNames
            -> LHsExpr GhcRn
            -- If this is @Just pure@, replace return by pure
            -- If this is @Nothing@, strip the return/pure
            -> Maybe (HsExpr GhcRn)
            -> Maybe (LHsExpr GhcRn, Maybe Bool)
isReturnApp :: MonadNames
-> XRec GhcRn (HsExpr GhcRn)
-> Maybe (HsExpr GhcRn)
-> Maybe (XRec GhcRn (HsExpr GhcRn), Maybe Bool)
isReturnApp MonadNames
monad_names (L SrcSpanAnnA
_ (HsPar XPar GhcRn
_ XRec GhcRn (HsExpr GhcRn)
expr)) Maybe (HsExpr GhcRn)
mb_pure =
  MonadNames
-> XRec GhcRn (HsExpr GhcRn)
-> Maybe (HsExpr GhcRn)
-> Maybe (XRec GhcRn (HsExpr GhcRn), Maybe Bool)
isReturnApp MonadNames
monad_names XRec GhcRn (HsExpr GhcRn)
expr Maybe (HsExpr GhcRn)
mb_pure
isReturnApp MonadNames
monad_names (L SrcSpanAnnA
loc HsExpr GhcRn
e) Maybe (HsExpr GhcRn)
mb_pure = case HsExpr GhcRn
e of
  OpApp XOpApp GhcRn
x XRec GhcRn (HsExpr GhcRn)
l XRec GhcRn (HsExpr GhcRn)
op XRec GhcRn (HsExpr GhcRn)
r
    | Just HsExpr GhcRn
pure_expr <- Maybe (HsExpr GhcRn)
mb_pure, GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_return XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
l, GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_dollar XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op ->
        (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
-> Maybe (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
forall a. a -> Maybe a
Just (SrcSpanAnnA
-> HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc (XOpApp GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p.
XOpApp p -> LHsExpr p -> LHsExpr p -> LHsExpr p -> HsExpr p
OpApp XOpApp GhcRn
x (GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall {l} {e} {e}. GenLocated l e -> e -> GenLocated l e
to_pure XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
l HsExpr GhcRn
pure_expr) XRec GhcRn (HsExpr GhcRn)
op XRec GhcRn (HsExpr GhcRn)
r), Maybe Bool
forall a. Maybe a
Nothing)
    | GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_return XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
l, GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_dollar XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
op -> (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
-> Maybe (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
forall a. a -> Maybe a
Just (XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
r, Bool -> Maybe Bool
forall a. a -> Maybe a
Just Bool
True)
  HsApp XApp GhcRn
x XRec GhcRn (HsExpr GhcRn)
f XRec GhcRn (HsExpr GhcRn)
arg
    | Just HsExpr GhcRn
pure_expr <- Maybe (HsExpr GhcRn)
mb_pure, GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_return XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
f ->
        (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
-> Maybe (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
forall a. a -> Maybe a
Just (SrcSpanAnnA
-> HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc (XApp GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XApp p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsApp XApp GhcRn
x (GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall {l} {e} {e}. GenLocated l e -> e -> GenLocated l e
to_pure XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
f HsExpr GhcRn
pure_expr) XRec GhcRn (HsExpr GhcRn)
arg), Maybe Bool
forall a. Maybe a
Nothing)
    | GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_return XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
f -> (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
-> Maybe (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
forall a. a -> Maybe a
Just (XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
arg, Bool -> Maybe Bool
forall a. a -> Maybe a
Just Bool
False)
  HsExpr GhcRn
_otherwise -> Maybe (XRec GhcRn (HsExpr GhcRn), Maybe Bool)
Maybe (GenLocated SrcSpanAnnA (HsExpr GhcRn), Maybe Bool)
forall a. Maybe a
Nothing
 where
  is_var :: (IdP p -> Bool) -> GenLocated l (HsExpr p) -> Bool
is_var IdP p -> Bool
f (L l
_ (HsPar XPar p
_ XRec p (HsExpr p)
e)) = (IdP p -> Bool) -> GenLocated l (HsExpr p) -> Bool
is_var IdP p -> Bool
f XRec p (HsExpr p)
GenLocated l (HsExpr p)
e
  is_var IdP p -> Bool
f (L l
_ (HsAppType XAppTypeE p
_ XRec p (HsExpr p)
e LHsWcType (NoGhcTc p)
_)) = (IdP p -> Bool) -> GenLocated l (HsExpr p) -> Bool
is_var IdP p -> Bool
f XRec p (HsExpr p)
GenLocated l (HsExpr p)
e
  is_var IdP p -> Bool
f (L l
_ (HsVar XVar p
_ (L l
_ IdP p
r))) = IdP p -> Bool
f IdP p
r
       -- TODO: I don't know how to get this right for rebindable syntax
  is_var IdP p -> Bool
_ GenLocated l (HsExpr p)
_ = Bool
False

  is_return :: GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_return = (IdP GhcRn -> Bool)
-> GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
forall {p} {l} {l}.
(XRec p (HsExpr p) ~ GenLocated l (HsExpr p),
 XRec p (IdP p) ~ GenLocated l (IdP p)) =>
(IdP p -> Bool) -> GenLocated l (HsExpr p) -> Bool
is_var (\IdP GhcRn
n -> IdP GhcRn
Name
n Name -> Name -> Bool
forall a. Eq a => a -> a -> Bool
== MonadNames -> Name
return_name MonadNames
monad_names
                         Bool -> Bool -> Bool
|| IdP GhcRn
Name
n Name -> Name -> Bool
forall a. Eq a => a -> a -> Bool
== MonadNames -> Name
pure_name MonadNames
monad_names)
  to_pure :: GenLocated l e -> e -> GenLocated l e
to_pure (L l
loc e
_) e
pure_expr = l -> e -> GenLocated l e
forall l e. l -> e -> GenLocated l e
L l
loc e
pure_expr
  is_dollar :: GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
is_dollar = (IdP GhcRn -> Bool)
-> GenLocated SrcSpanAnnA (HsExpr GhcRn) -> Bool
forall {p} {l} {l}.
(XRec p (HsExpr p) ~ GenLocated l (HsExpr p),
 XRec p (IdP p) ~ GenLocated l (IdP p)) =>
(IdP p -> Bool) -> GenLocated l (HsExpr p) -> Bool
is_var (IdP GhcRn -> Unique -> Bool
forall a. Uniquable a => a -> Unique -> Bool
`hasKey` Unique
dollarIdKey)

{-
************************************************************************
*                                                                      *
\subsubsection{Errors}
*                                                                      *
************************************************************************
-}

checkEmptyStmts :: HsStmtContextRn -> RnM ()
-- We've seen an empty sequence of Stmts... is that ok?
checkEmptyStmts :: HsStmtContextRn -> IOEnv (Env TcGblEnv TcLclEnv) ()
checkEmptyStmts HsStmtContextRn
ctxt
  = (EmptyStatementGroupErrReason -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> Maybe EmptyStatementGroupErrReason
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> (EmptyStatementGroupErrReason -> TcRnMessage)
-> EmptyStatementGroupErrReason
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. EmptyStatementGroupErrReason -> TcRnMessage
TcRnEmptyStmtsGroup) Maybe EmptyStatementGroupErrReason
mb_err
  where
    mb_err :: Maybe EmptyStatementGroupErrReason
mb_err = case HsStmtContextRn
ctxt of
      PatGuard {}      -> Maybe EmptyStatementGroupErrReason
forall a. Maybe a
Nothing -- Pattern guards can be empty
      ParStmtCtxt {}   -> EmptyStatementGroupErrReason -> Maybe EmptyStatementGroupErrReason
forall a. a -> Maybe a
Just EmptyStatementGroupErrReason
EmptyStmtsGroupInParallelComp
      TransStmtCtxt {} -> EmptyStatementGroupErrReason -> Maybe EmptyStatementGroupErrReason
forall a. a -> Maybe a
Just EmptyStatementGroupErrReason
EmptyStmtsGroupInTransformListComp
      HsDoStmt HsDoFlavour
flav    -> EmptyStatementGroupErrReason -> Maybe EmptyStatementGroupErrReason
forall a. a -> Maybe a
Just (EmptyStatementGroupErrReason
 -> Maybe EmptyStatementGroupErrReason)
-> EmptyStatementGroupErrReason
-> Maybe EmptyStatementGroupErrReason
forall a b. (a -> b) -> a -> b
$ HsDoFlavour -> EmptyStatementGroupErrReason
EmptyStmtsGroupInDoNotation HsDoFlavour
flav
      HsStmtContextRn
ArrowExpr        -> EmptyStatementGroupErrReason -> Maybe EmptyStatementGroupErrReason
forall a. a -> Maybe a
Just EmptyStatementGroupErrReason
EmptyStmtsGroupInArrowNotation

----------------------
checkLastStmt :: AnnoBody body
              => HsStmtContextRn
              -> LStmt GhcPs (LocatedA (body GhcPs))
              -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
checkLastStmt :: forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
checkLastStmt HsStmtContextRn
ctxt lstmt :: LStmt GhcPs (LocatedA (body GhcPs))
lstmt@(L SrcSpanAnnA
loc StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
stmt)
  = case HsStmtContextRn
ctxt of
      HsDoStmt HsDoFlavour
ListComp  -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_comp
      HsDoStmt HsDoFlavour
MonadComp -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_comp
      HsDoStmt DoExpr{}  -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_do
      HsDoStmt MDoExpr{} -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_do
      HsStmtContextRn
ArrowExpr -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_do
      HsStmtContextRn
_         -> RnM (LStmt GhcPs (LocatedA (body GhcPs)))
IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_other
  where
    check_do :: IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_do    -- Expect BodyStmt, and change it to LastStmt
      = case StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
stmt of
          BodyStmt XBodyStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ LocatedA (body GhcPs)
e SyntaxExpr GhcPs
_ SyntaxExpr GhcPs
_ -> GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (SrcSpanAnnA
-> StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
-> GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
forall l e. l -> e -> GenLocated l e
L SrcSpanAnnA
loc (LocatedA (body GhcPs) -> StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
forall (idR :: Pass) (bodyR :: * -> *) (idL :: Pass).
IsPass idR =>
LocatedA (bodyR (GhcPass idR))
-> StmtLR
     (GhcPass idL) (GhcPass idR) (LocatedA (bodyR (GhcPass idR)))
mkLastStmt LocatedA (body GhcPs)
e))
          LastStmt {}      -> GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
lstmt   -- "Deriving" clauses may generate a
                                             -- LastStmt directly (unlike the parser)
          StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
_                -> do { TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$ HsStmtContextRn -> UnexpectedStatement -> TcRnMessage
TcRnLastStmtNotExpr HsStmtContextRn
ctxt
                                          (UnexpectedStatement -> TcRnMessage)
-> UnexpectedStatement -> TcRnMessage
forall a b. (a -> b) -> a -> b
$ StmtLR GhcPs GhcPs (LocatedA (body GhcPs)) -> UnexpectedStatement
forall body.
Outputable (StmtLR GhcPs GhcPs body) =>
StmtLR GhcPs GhcPs body -> UnexpectedStatement
UnexpectedStatement StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
stmt
                                 ; GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
lstmt }


    check_comp :: IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_comp  -- Expect LastStmt; this should be enforced by the parser!
      = case StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
stmt of
          LastStmt {} -> GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
lstmt
          StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
_           -> String
-> SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"checkLastStmt" (GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> SDoc
forall a. Outputable a => a -> SDoc
ppr LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
lstmt)

    check_other :: IOEnv
  (Env TcGblEnv TcLclEnv)
  (GenLocated
     SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
check_other -- Behave just as if this wasn't the last stmt
      = do { HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> IOEnv (Env TcGblEnv TcLclEnv) ()
forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> IOEnv (Env TcGblEnv TcLclEnv) ()
checkStmt HsStmtContextRn
ctxt LStmt GhcPs (LocatedA (body GhcPs))
lstmt; GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))))
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return LStmt GhcPs (LocatedA (body GhcPs))
GenLocated SrcSpanAnnA (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)))
lstmt }

-- Checking when a particular Stmt is ok
checkStmt :: AnnoBody body
          => HsStmtContextRn
          -> LStmt GhcPs (LocatedA (body GhcPs))
          -> RnM ()
checkStmt :: forall (body :: * -> *).
AnnoBody body =>
HsStmtContextRn
-> LStmt GhcPs (LocatedA (body GhcPs))
-> IOEnv (Env TcGblEnv TcLclEnv) ()
checkStmt HsStmtContextRn
ctxt (L SrcSpanAnnA
_ StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
stmt)
  = do { dflags <- IOEnv (Env TcGblEnv TcLclEnv) DynFlags
forall (m :: * -> *). HasDynFlags m => m DynFlags
getDynFlags
       ; case okStmt dflags ctxt stmt of
           Validity' (Maybe Extension)
IsValid      -> () -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return ()
           NotValid Maybe Extension
ext -> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
addErr (TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ())
-> TcRnMessage -> IOEnv (Env TcGblEnv TcLclEnv) ()
forall a b. (a -> b) -> a -> b
$
              HsStmtContextRn
-> UnexpectedStatement -> Maybe Extension -> TcRnMessage
TcRnUnexpectedStatementInContext
                HsStmtContextRn
ctxt (StmtLR GhcPs GhcPs (LocatedA (body GhcPs)) -> UnexpectedStatement
forall body.
Outputable (StmtLR GhcPs GhcPs body) =>
StmtLR GhcPs GhcPs body -> UnexpectedStatement
UnexpectedStatement StmtLR GhcPs GhcPs (LocatedA (body GhcPs))
stmt) Maybe Extension
ext }

------------
emptyInvalid :: Validity' (Maybe LangExt.Extension)
emptyInvalid :: Validity' (Maybe Extension)
emptyInvalid = Maybe Extension -> Validity' (Maybe Extension)
forall a. a -> Validity' a
NotValid Maybe Extension
forall a. Maybe a
Nothing -- Invalid, and no extension to suggest

okStmt, okDoStmt, okCompStmt, okParStmt
   :: DynFlags -> HsStmtContextRn
   -> Stmt GhcPs (LocatedA (body GhcPs)) -> Validity' (Maybe LangExt.Extension)
-- Return Nothing if OK, (Just extra) if not ok
-- The "extra" is an SDoc that is appended to a generic error message

okStmt :: forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
  = case HsStmtContextRn
ctxt of
      PatGuard {}        -> Stmt GhcPs (LocatedA (body GhcPs)) -> Validity' (Maybe Extension)
forall (body :: * -> *).
Stmt GhcPs (LocatedA (body GhcPs)) -> Validity' (Maybe Extension)
okPatGuardStmt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      ParStmtCtxt HsStmtContextRn
ctxt   -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okParStmt  DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      HsDoStmt HsDoFlavour
flavour   -> DynFlags
-> HsDoFlavour
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsDoFlavour
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoFlavourStmt DynFlags
dflags HsDoFlavour
flavour HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      HsStmtContextRn
ArrowExpr          -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoStmt   DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      TransStmtCtxt HsStmtContextRn
ctxt -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt

okDoFlavourStmt
  :: DynFlags -> HsDoFlavour -> HsStmtContextRn
  -> Stmt GhcPs (LocatedA (body GhcPs)) -> Validity' (Maybe LangExt.Extension)
okDoFlavourStmt :: forall (body :: * -> *).
DynFlags
-> HsDoFlavour
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoFlavourStmt DynFlags
dflags HsDoFlavour
flavour HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt = case HsDoFlavour
flavour of
      DoExpr{}     -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoStmt   DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      MDoExpr{}    -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoStmt   DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      HsDoFlavour
GhciStmtCtxt -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoStmt   DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      HsDoFlavour
ListComp     -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okCompStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
      HsDoFlavour
MonadComp    -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okCompStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt

-------------
okPatGuardStmt :: Stmt GhcPs (LocatedA (body GhcPs)) -> Validity' (Maybe LangExt.Extension)
okPatGuardStmt :: forall (body :: * -> *).
Stmt GhcPs (LocatedA (body GhcPs)) -> Validity' (Maybe Extension)
okPatGuardStmt Stmt GhcPs (LocatedA (body GhcPs))
stmt
  = case Stmt GhcPs (LocatedA (body GhcPs))
stmt of
      BodyStmt {} -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
      BindStmt {} -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
      LetStmt {}  -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
      Stmt GhcPs (LocatedA (body GhcPs))
_           -> Validity' (Maybe Extension)
emptyInvalid

-------------
okParStmt :: forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okParStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
  = case Stmt GhcPs (LocatedA (body GhcPs))
stmt of
      LetStmt XLetStmt GhcPs GhcPs (LocatedA (body GhcPs))
_ (HsIPBinds {}) -> Validity' (Maybe Extension)
emptyInvalid
      Stmt GhcPs (LocatedA (body GhcPs))
_                        -> DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt

----------------
okDoStmt :: forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okDoStmt DynFlags
dflags HsStmtContextRn
ctxt Stmt GhcPs (LocatedA (body GhcPs))
stmt
  = case Stmt GhcPs (LocatedA (body GhcPs))
stmt of
       RecStmt {}
         | Extension
LangExt.RecursiveDo Extension -> DynFlags -> Bool
`xopt` DynFlags
dflags -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
         | HsStmtContextRn
ArrowExpr <- HsStmtContextRn
ctxt -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid    -- Arrows allows 'rec'
         | Bool
otherwise         -> Maybe Extension -> Validity' (Maybe Extension)
forall a. a -> Validity' a
NotValid (Extension -> Maybe Extension
forall a. a -> Maybe a
Just Extension
LangExt.RecursiveDo)
       BindStmt {} -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
       LetStmt {}  -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
       BodyStmt {} -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
       Stmt GhcPs (LocatedA (body GhcPs))
_           -> Validity' (Maybe Extension)
emptyInvalid

----------------
okCompStmt :: forall (body :: * -> *).
DynFlags
-> HsStmtContextRn
-> Stmt GhcPs (LocatedA (body GhcPs))
-> Validity' (Maybe Extension)
okCompStmt DynFlags
dflags HsStmtContextRn
_ Stmt GhcPs (LocatedA (body GhcPs))
stmt
  = case Stmt GhcPs (LocatedA (body GhcPs))
stmt of
       BindStmt {} -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
       LetStmt {}  -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
       BodyStmt {} -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
       ParStmt {}
         | Extension
LangExt.ParallelListComp Extension -> DynFlags -> Bool
`xopt` DynFlags
dflags -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
         | Bool
otherwise -> Maybe Extension -> Validity' (Maybe Extension)
forall a. a -> Validity' a
NotValid (Extension -> Maybe Extension
forall a. a -> Maybe a
Just Extension
LangExt.ParallelListComp)
       TransStmt {}
         | Extension
LangExt.TransformListComp Extension -> DynFlags -> Bool
`xopt` DynFlags
dflags -> Validity' (Maybe Extension)
forall a. Validity' a
IsValid
         | Bool
otherwise -> Maybe Extension -> Validity' (Maybe Extension)
forall a. a -> Validity' a
NotValid (Extension -> Maybe Extension
forall a. a -> Maybe a
Just Extension
LangExt.TransformListComp)
       RecStmt {}  -> Validity' (Maybe Extension)
emptyInvalid
       LastStmt {} -> Validity' (Maybe Extension)
emptyInvalid  -- Should not happen (dealt with by checkLastStmt)
       ApplicativeStmt {} -> Validity' (Maybe Extension)
emptyInvalid

---------
checkTupleSection :: [HsTupArg GhcPs] -> RnM ()
checkTupleSection :: [HsTupArg GhcPs] -> IOEnv (Env TcGblEnv TcLclEnv) ()
checkTupleSection [HsTupArg GhcPs]
args
  = do  { tuple_section <- Extension -> TcRnIf TcGblEnv TcLclEnv Bool
forall gbl lcl. Extension -> TcRnIf gbl lcl Bool
xoptM Extension
LangExt.TupleSections
        ; checkErr (all tupArgPresent args || tuple_section) msg }
  where
    msg :: TcRnMessage
    msg :: TcRnMessage
msg = TcRnMessage
TcRnIllegalTupleSection

---------
sectionErr :: HsExpr GhcPs -> TcRnMessage
sectionErr :: HsExpr GhcPs -> TcRnMessage
sectionErr = HsExpr GhcPs -> TcRnMessage
TcRnSectionWithoutParentheses

badIpBinds :: Either (HsLocalBindsLR GhcPs GhcPs) (HsLocalBindsLR GhcRn GhcPs) -> TcRnMessage
badIpBinds :: Either (HsLocalBinds GhcPs) (HsLocalBindsLR GhcRn GhcPs)
-> TcRnMessage
badIpBinds = Either (HsLocalBinds GhcPs) (HsLocalBindsLR GhcRn GhcPs)
-> TcRnMessage
TcRnIllegalImplicitParameterBindings

---------

monadFailOp :: LPat GhcPs
            -> HsStmtContextRn
            -> RnM (FailOperator GhcRn, FreeVars)
monadFailOp :: LPat GhcPs
-> HsStmtContextRn -> RnM (Maybe (SyntaxExpr GhcRn), FreeVars)
monadFailOp LPat GhcPs
pat HsStmtContextRn
ctxt = do
    dflags <- IOEnv (Env TcGblEnv TcLclEnv) DynFlags
forall (m :: * -> *). HasDynFlags m => m DynFlags
getDynFlags
        -- If the pattern is irrefutable (e.g.: wildcard, tuple, ~pat, etc.)
        -- we should not need to fail.
    if | isIrrefutableHsPat dflags pat -> return (Nothing, emptyFVs)

        -- For non-monadic contexts (e.g. guard patterns, list
        -- comprehensions, etc.) we should not need to fail, or failure is handled in
        -- a different way. See Note [Failing pattern matches in Stmts].
       | not (isMonadStmtContext ctxt) -> return (Nothing, emptyFVs)

       | otherwise -> getMonadFailOp ctxt

{-
Note [Monad fail : Rebindable syntax, overloaded strings]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Given the code
  foo x = do { Just y <- x; return y }

we expect it to desugar as
  foo x = x >>= \r -> case r of
                        Just y  -> return y
                        Nothing -> fail "Pattern match error"

But with RebindableSyntax and OverloadedStrings, we really want
it to desugar thus:
  foo x = x >>= \r -> case r of
                        Just y  -> return y
                        Nothing -> fail (fromString "Patterm match error")

So, in this case, we synthesize the function
  \x -> fail (fromString x)

(rather than plain 'fail') for the 'fail' operation. This is done in
'getMonadFailOp'.

Similarly with QualifiedDo and OverloadedStrings, we also want to desugar
using fromString:

  foo x = M.do { Just y <- x; return y }

  ===>

  foo x = x M.>>= \r -> case r of
                        Just y  -> return y
                        Nothing -> M.fail (fromString "Pattern match error")

-}
getMonadFailOp :: HsStmtContext fn -> RnM (FailOperator GhcRn, FreeVars) -- Syntax expr fail op
getMonadFailOp :: forall fn.
HsStmtContext fn -> RnM (Maybe (SyntaxExpr GhcRn), FreeVars)
getMonadFailOp HsStmtContext fn
ctxt
 = do { xOverloadedStrings <- (DynFlags -> Bool)
-> IOEnv (Env TcGblEnv TcLclEnv) DynFlags
-> TcRnIf TcGblEnv TcLclEnv Bool
forall a b.
(a -> b)
-> IOEnv (Env TcGblEnv TcLclEnv) a
-> IOEnv (Env TcGblEnv TcLclEnv) b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (Extension -> DynFlags -> Bool
xopt Extension
LangExt.OverloadedStrings) IOEnv (Env TcGblEnv TcLclEnv) DynFlags
forall (m :: * -> *). HasDynFlags m => m DynFlags
getDynFlags
      ; xRebindableSyntax <- fmap (xopt LangExt.RebindableSyntax) getDynFlags
      ; (fail, fvs) <- reallyGetMonadFailOp xRebindableSyntax xOverloadedStrings
      ; return (Just fail, fvs)
      }
  where
    isQualifiedDo :: Bool
isQualifiedDo = Maybe ModuleName -> Bool
forall a. Maybe a -> Bool
isJust (HsStmtContext fn -> Maybe ModuleName
forall fn. HsStmtContext fn -> Maybe ModuleName
qualifiedDoModuleName_maybe HsStmtContext fn
ctxt)

    reallyGetMonadFailOp :: Bool
-> Bool -> IOEnv (Env TcGblEnv TcLclEnv) (SyntaxExprRn, FreeVars)
reallyGetMonadFailOp Bool
rebindableSyntax Bool
overloadedStrings
      | (Bool
isQualifiedDo Bool -> Bool -> Bool
|| Bool
rebindableSyntax) Bool -> Bool -> Bool
&& Bool
overloadedStrings = do
        (failExpr, failFvs) <- HsStmtContext fn -> Name -> TcM (HsExpr GhcRn, FreeVars)
forall fn. HsStmtContext fn -> Name -> TcM (HsExpr GhcRn, FreeVars)
lookupQualifiedDoExpr HsStmtContext fn
ctxt Name
failMName
        (fromStringExpr, fromStringFvs) <- lookupSyntaxExpr fromStringName
        let arg_lit = FastString -> OccName
mkVarOccFS (String -> FastString
fsLit String
"arg")
        arg_name <- newSysName arg_lit
        let arg_syn_expr = IdP GhcRn -> XRec GhcRn (HsExpr GhcRn)
forall (p :: Pass) a.
IsSrcSpanAnn p a =>
IdP (GhcPass p) -> LHsExpr (GhcPass p)
nlHsVar IdP GhcRn
Name
arg_name
            body :: LHsExpr GhcRn =
              nlHsApp (noLocA failExpr)
                      (nlHsApp (noLocA $ fromStringExpr) arg_syn_expr)
        let failAfterFromStringExpr :: HsExpr GhcRn =
              unLoc $ mkHsLam [noLocA $ VarPat noExtField $ noLocA arg_name] body
        let failAfterFromStringSynExpr :: SyntaxExpr GhcRn =
              mkSyntaxExpr failAfterFromStringExpr
        return (failAfterFromStringSynExpr, failFvs `plusFV` fromStringFvs)
      | Bool
otherwise = HsStmtContext fn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
forall fn.
HsStmtContext fn -> Name -> RnM (SyntaxExpr GhcRn, FreeVars)
lookupQualifiedDo HsStmtContext fn
ctxt Name
failMName


{- *********************************************************************
*                                                                      *
              Generating code for ExpandedThingRn
      See Note [Handling overloaded and rebindable constructs]
*                                                                      *
********************************************************************* -}

-- | Expand `HsIf` if rebindable syntax is turned on
--   See Note [Handling overloaded and rebindable constructs]
rnHsIf :: LHsExpr GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs -> RnM (HsExpr GhcRn, FreeVars)
rnHsIf :: LHsExpr GhcPs
-> LHsExpr GhcPs -> LHsExpr GhcPs -> TcM (HsExpr GhcRn, FreeVars)
rnHsIf LHsExpr GhcPs
p LHsExpr GhcPs
b1 LHsExpr GhcPs
b2
  = do { (p',  fvP)  <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
p
       ; (b1', fvB1) <- rnLExpr b1
       ; (b2', fvB2) <- rnLExpr b2
       ; let fvs_if = [FreeVars] -> FreeVars
plusFVs [FreeVars
fvP, FreeVars
fvB1, FreeVars
fvB2]
             rn_if  = XIf GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
forall p. XIf p -> LHsExpr p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsIf XIf GhcRn
NoExtField
noExtField  XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
p' XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
b1' XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
b2'

       -- Deal with rebindable syntax
       ; mb_ite <- lookupIfThenElse
       ; case mb_ite of
            Maybe Name
Nothing  -- Non rebindable-syntax case
              -> (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcRn
rn_if, FreeVars
fvs_if)

            Just Name
ite_name   -- Rebindable-syntax case
              -> do { let ds_if :: HsExpr GhcRn
ds_if = Name -> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
genHsApps Name
ite_name [XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
p', XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
b1', XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
b2']
                          fvs :: FreeVars
fvs   = [FreeVars] -> FreeVars
plusFVs [FreeVars
fvs_if, Name -> FreeVars
unitFV Name
ite_name]
                    ; (HsExpr GhcRn, FreeVars) -> TcM (HsExpr GhcRn, FreeVars)
forall a. a -> IOEnv (Env TcGblEnv TcLclEnv) a
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcRn -> HsExpr GhcRn -> HsExpr GhcRn
mkExpandedExpr HsExpr GhcRn
rn_if HsExpr GhcRn
ds_if, FreeVars
fvs) } }

-----------------------------------------
-- Bits and pieces for RecordDotSyntax.
--
-- See Note [Overview of record dot syntax] in GHC.Hs.Expr.

-- mkGetField arg field calculates a get_field @field arg expression.
-- e.g. z.x = mkGetField z x = get_field @x z
mkGetField :: Name -> LHsExpr GhcRn -> LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
mkGetField :: Name
-> XRec GhcRn (HsExpr GhcRn)
-> LocatedAn NoEpAnns FieldLabelString
-> HsExpr GhcRn
mkGetField Name
get_field XRec GhcRn (HsExpr GhcRn)
arg LocatedAn NoEpAnns FieldLabelString
field = GenLocated SrcSpanAnnA (HsExpr GhcRn) -> HsExpr GhcRn
forall l e. GenLocated l e -> e
unLoc ([XRec GhcRn (HsExpr GhcRn)] -> XRec GhcRn (HsExpr GhcRn)
forall a. HasCallStack => [a] -> a
head ([XRec GhcRn (HsExpr GhcRn)] -> XRec GhcRn (HsExpr GhcRn))
-> [XRec GhcRn (HsExpr GhcRn)] -> XRec GhcRn (HsExpr GhcRn)
forall a b. (a -> b) -> a -> b
$ Name
-> [XRec GhcRn (HsExpr GhcRn)]
-> LocatedAn NoEpAnns FieldLabelString
-> [XRec GhcRn (HsExpr GhcRn)]
mkGet Name
get_field [XRec GhcRn (HsExpr GhcRn)
arg] LocatedAn NoEpAnns FieldLabelString
field)

-- mkSetField a field b calculates a set_field @field expression.
-- e.g mkSetSetField a field b = set_field @"field" a b (read as "set field 'field' on a to b").
mkSetField :: Name -> LHsExpr GhcRn -> LocatedAn NoEpAnns FieldLabelString -> LHsExpr GhcRn -> HsExpr GhcRn
mkSetField :: Name
-> XRec GhcRn (HsExpr GhcRn)
-> LocatedAn NoEpAnns FieldLabelString
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
mkSetField Name
set_field XRec GhcRn (HsExpr GhcRn)
a (L EpAnn NoEpAnns
_ (FieldLabelString FastString
field)) XRec GhcRn (HsExpr GhcRn)
b =
  HsExpr GhcRn -> XRec GhcRn (HsExpr GhcRn) -> HsExpr GhcRn
genHsApp (HsExpr GhcRn -> XRec GhcRn (HsExpr GhcRn) -> HsExpr GhcRn
genHsApp (Name -> HsExpr GhcRn
genHsVar Name
set_field HsExpr GhcRn -> HsType (NoGhcTc GhcRn) -> HsExpr GhcRn
`genAppType` FastString -> HsType GhcRn
genHsTyLit FastString
field)  XRec GhcRn (HsExpr GhcRn)
a) XRec GhcRn (HsExpr GhcRn)
b

mkGet :: Name -> [LHsExpr GhcRn] -> LocatedAn NoEpAnns FieldLabelString -> [LHsExpr GhcRn]
mkGet :: Name
-> [XRec GhcRn (HsExpr GhcRn)]
-> LocatedAn NoEpAnns FieldLabelString
-> [XRec GhcRn (HsExpr GhcRn)]
mkGet Name
get_field l :: [XRec GhcRn (HsExpr GhcRn)]
l@(XRec GhcRn (HsExpr GhcRn)
r : [XRec GhcRn (HsExpr GhcRn)]
_) (L EpAnn NoEpAnns
_ (FieldLabelString FastString
field)) =
  HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan (HsExpr GhcRn -> XRec GhcRn (HsExpr GhcRn) -> HsExpr GhcRn
genHsApp (Name -> HsExpr GhcRn
genHsVar Name
get_field HsExpr GhcRn -> HsType (NoGhcTc GhcRn) -> HsExpr GhcRn
`genAppType` FastString -> HsType GhcRn
genHsTyLit FastString
field) XRec GhcRn (HsExpr GhcRn)
r) GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
forall a. a -> [a] -> [a]
: [XRec GhcRn (HsExpr GhcRn)]
[GenLocated SrcSpanAnnA (HsExpr GhcRn)]
l
mkGet Name
_ [] LocatedAn NoEpAnns FieldLabelString
_ = String -> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
forall a. HasCallStack => String -> a
panic String
"mkGet : The impossible has happened!"

mkSet :: Name -> LHsExpr GhcRn -> (LocatedAn NoEpAnns FieldLabelString, LHsExpr GhcRn) -> LHsExpr GhcRn
mkSet :: Name
-> XRec GhcRn (HsExpr GhcRn)
-> (LocatedAn NoEpAnns FieldLabelString, XRec GhcRn (HsExpr GhcRn))
-> XRec GhcRn (HsExpr GhcRn)
mkSet Name
set_field XRec GhcRn (HsExpr GhcRn)
acc (LocatedAn NoEpAnns FieldLabelString
field, XRec GhcRn (HsExpr GhcRn)
g) = HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan (Name
-> XRec GhcRn (HsExpr GhcRn)
-> LocatedAn NoEpAnns FieldLabelString
-> XRec GhcRn (HsExpr GhcRn)
-> HsExpr GhcRn
mkSetField Name
set_field XRec GhcRn (HsExpr GhcRn)
g LocatedAn NoEpAnns FieldLabelString
field XRec GhcRn (HsExpr GhcRn)
acc)

-- mkProjection fields calculates a projection.
-- e.g. .x = mkProjection [x] = getField @"x"
--      .x.y = mkProjection [.x, .y] = (.y) . (.x) = getField @"y" . getField @"x"
mkProjection :: Name -> Name -> NonEmpty (LocatedAn NoEpAnns FieldLabelString) -> HsExpr GhcRn
mkProjection :: Name
-> Name
-> NonEmpty (LocatedAn NoEpAnns FieldLabelString)
-> HsExpr GhcRn
mkProjection Name
getFieldName Name
circName (LocatedAn NoEpAnns FieldLabelString
field :| [LocatedAn NoEpAnns FieldLabelString]
fields) = (HsExpr GhcRn
 -> LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn)
-> HsExpr GhcRn
-> [LocatedAn NoEpAnns FieldLabelString]
-> HsExpr GhcRn
forall b a. (b -> a -> b) -> b -> [a] -> b
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' HsExpr GhcRn -> LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
f (LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
proj LocatedAn NoEpAnns FieldLabelString
field) [LocatedAn NoEpAnns FieldLabelString]
fields
  where
    f :: HsExpr GhcRn -> LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
    f :: HsExpr GhcRn -> LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
f HsExpr GhcRn
acc LocatedAn NoEpAnns FieldLabelString
field = Name -> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
genHsApps Name
circName ([XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn)
-> [XRec GhcRn (HsExpr GhcRn)] -> HsExpr GhcRn
forall a b. (a -> b) -> a -> b
$ (HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> [HsExpr GhcRn] -> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
forall a b. (a -> b) -> [a] -> [b]
map HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan [LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
proj LocatedAn NoEpAnns FieldLabelString
field, HsExpr GhcRn
acc]

    proj :: LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
    proj :: LocatedAn NoEpAnns FieldLabelString -> HsExpr GhcRn
proj (L EpAnn NoEpAnns
_ (FieldLabelString FastString
f)) = Name -> HsExpr GhcRn
genHsVar Name
getFieldName HsExpr GhcRn -> HsType (NoGhcTc GhcRn) -> HsExpr GhcRn
`genAppType` FastString -> HsType GhcRn
genHsTyLit FastString
f

-- mkProjUpdateSetField calculates functions representing dot notation record updates.
-- e.g. Suppose an update like foo.bar = 1.
--      We calculate the function \a -> setField @"foo" a (setField @"bar" (getField @"foo" a) 1).
mkProjUpdateSetField :: Name -> Name -> LHsRecProj GhcRn (LHsExpr GhcRn) -> (LHsExpr GhcRn -> LHsExpr GhcRn)
mkProjUpdateSetField :: Name
-> Name
-> LHsRecUpdProj GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
mkProjUpdateSetField Name
get_field Name
set_field (L SrcSpanAnnA
_ (HsFieldBind { hfbLHS :: forall lhs rhs. HsFieldBind lhs rhs -> lhs
hfbLHS = (L EpAnn NoEpAnns
_ (FieldLabelStrings [XRec GhcRn (DotFieldOcc GhcRn)]
flds')), hfbRHS :: forall lhs rhs. HsFieldBind lhs rhs -> rhs
hfbRHS = GenLocated SrcSpanAnnA (HsExpr GhcRn)
arg } ))
  = let {
      ; flds :: [LocatedAn NoEpAnns FieldLabelString]
flds = (LocatedAn NoEpAnns (DotFieldOcc GhcRn)
 -> LocatedAn NoEpAnns FieldLabelString)
-> [LocatedAn NoEpAnns (DotFieldOcc GhcRn)]
-> [LocatedAn NoEpAnns FieldLabelString]
forall a b. (a -> b) -> [a] -> [b]
map ((DotFieldOcc GhcRn -> FieldLabelString)
-> LocatedAn NoEpAnns (DotFieldOcc GhcRn)
-> LocatedAn NoEpAnns FieldLabelString
forall a b.
(a -> b)
-> GenLocated (EpAnn NoEpAnns) a -> GenLocated (EpAnn NoEpAnns) b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (GenLocated SrcSpanAnnN FieldLabelString -> FieldLabelString
forall l e. GenLocated l e -> e
unLoc (GenLocated SrcSpanAnnN FieldLabelString -> FieldLabelString)
-> (DotFieldOcc GhcRn -> GenLocated SrcSpanAnnN FieldLabelString)
-> DotFieldOcc GhcRn
-> FieldLabelString
forall b c a. (b -> c) -> (a -> b) -> a -> c
. DotFieldOcc GhcRn -> XRec GhcRn FieldLabelString
DotFieldOcc GhcRn -> GenLocated SrcSpanAnnN FieldLabelString
forall p. DotFieldOcc p -> XRec p FieldLabelString
dfoLabel)) [XRec GhcRn (DotFieldOcc GhcRn)]
[LocatedAn NoEpAnns (DotFieldOcc GhcRn)]
flds'
      ; final :: LocatedAn NoEpAnns FieldLabelString
final = [LocatedAn NoEpAnns FieldLabelString]
-> LocatedAn NoEpAnns FieldLabelString
forall a. HasCallStack => [a] -> a
last [LocatedAn NoEpAnns FieldLabelString]
flds  -- quux
      ; fields :: [LocatedAn NoEpAnns FieldLabelString]
fields = [LocatedAn NoEpAnns FieldLabelString]
-> [LocatedAn NoEpAnns FieldLabelString]
forall a. HasCallStack => [a] -> [a]
init [LocatedAn NoEpAnns FieldLabelString]
flds   -- [foo, bar, baz]
      ; getters :: GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
getters = \GenLocated SrcSpanAnnA (HsExpr GhcRn)
a -> ([GenLocated SrcSpanAnnA (HsExpr GhcRn)]
 -> LocatedAn NoEpAnns FieldLabelString
 -> [GenLocated SrcSpanAnnA (HsExpr GhcRn)])
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
-> [LocatedAn NoEpAnns FieldLabelString]
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
forall b a. (b -> a -> b) -> b -> [a] -> b
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' (Name
-> [XRec GhcRn (HsExpr GhcRn)]
-> LocatedAn NoEpAnns FieldLabelString
-> [XRec GhcRn (HsExpr GhcRn)]
mkGet Name
get_field) [GenLocated SrcSpanAnnA (HsExpr GhcRn)
a] [LocatedAn NoEpAnns FieldLabelString]
fields  -- Ordered from deep to shallow.
          -- [getField@"baz"(getField@"bar"(getField@"foo" a), getField@"bar"(getField@"foo" a), getField@"foo" a, a]
      ; zips :: GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [(LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))]
zips = \GenLocated SrcSpanAnnA (HsExpr GhcRn)
a -> (LocatedAn NoEpAnns FieldLabelString
final, [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
-> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall a. HasCallStack => [a] -> a
head (GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
getters GenLocated SrcSpanAnnA (HsExpr GhcRn)
a)) (LocatedAn NoEpAnns FieldLabelString,
 GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> [(LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))]
-> [(LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))]
forall a. a -> [a] -> [a]
: [LocatedAn NoEpAnns FieldLabelString]
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
-> [(LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))]
forall a b. [a] -> [b] -> [(a, b)]
zip ([LocatedAn NoEpAnns FieldLabelString]
-> [LocatedAn NoEpAnns FieldLabelString]
forall a. [a] -> [a]
reverse [LocatedAn NoEpAnns FieldLabelString]
fields) ([GenLocated SrcSpanAnnA (HsExpr GhcRn)]
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
forall a. HasCallStack => [a] -> [a]
tail (GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [GenLocated SrcSpanAnnA (HsExpr GhcRn)]
getters GenLocated SrcSpanAnnA (HsExpr GhcRn)
a)) -- Ordered from deep to shallow.
          -- [("quux", getField@"baz"(getField@"bar"(getField@"foo" a)), ("baz", getField@"bar"(getField@"foo" a)), ("bar", getField@"foo" a), ("foo", a)]
      }
    in (\XRec GhcRn (HsExpr GhcRn)
a -> (GenLocated SrcSpanAnnA (HsExpr GhcRn)
 -> (LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))
 -> GenLocated SrcSpanAnnA (HsExpr GhcRn))
-> GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [(LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))]
-> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall b a. (b -> a -> b) -> b -> [a] -> b
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' (Name
-> XRec GhcRn (HsExpr GhcRn)
-> (LocatedAn NoEpAnns FieldLabelString, XRec GhcRn (HsExpr GhcRn))
-> XRec GhcRn (HsExpr GhcRn)
mkSet Name
set_field) GenLocated SrcSpanAnnA (HsExpr GhcRn)
arg (GenLocated SrcSpanAnnA (HsExpr GhcRn)
-> [(LocatedAn NoEpAnns FieldLabelString,
     GenLocated SrcSpanAnnA (HsExpr GhcRn))]
zips XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
a))
          -- setField@"foo" (a) (setField@"bar" (getField @"foo" (a))(setField@"baz" (getField @"bar" (getField @"foo" (a)))(setField@"quux" (getField @"baz" (getField @"bar" (getField @"foo" (a))))(quux))))

mkRecordDotUpd :: Name -> Name -> LHsExpr GhcRn -> [LHsRecUpdProj GhcRn] -> HsExpr GhcRn
mkRecordDotUpd :: Name
-> Name
-> XRec GhcRn (HsExpr GhcRn)
-> [LHsRecUpdProj GhcRn]
-> HsExpr GhcRn
mkRecordDotUpd Name
get_field Name
set_field XRec GhcRn (HsExpr GhcRn)
exp [LHsRecUpdProj GhcRn]
updates = (HsExpr GhcRn
 -> GenLocated
      SrcSpanAnnA
      (HsFieldBind
         (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
         (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
 -> HsExpr GhcRn)
-> HsExpr GhcRn
-> [GenLocated
      SrcSpanAnnA
      (HsFieldBind
         (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
         (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
-> HsExpr GhcRn
forall b a. (b -> a -> b) -> b -> [a] -> b
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' HsExpr GhcRn -> LHsRecUpdProj GhcRn -> HsExpr GhcRn
HsExpr GhcRn
-> GenLocated
     SrcSpanAnnA
     (HsFieldBind
        (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
        (GenLocated SrcSpanAnnA (HsExpr GhcRn)))
-> HsExpr GhcRn
fieldUpdate (GenLocated SrcSpanAnnA (HsExpr GhcRn) -> HsExpr GhcRn
forall l e. GenLocated l e -> e
unLoc XRec GhcRn (HsExpr GhcRn)
GenLocated SrcSpanAnnA (HsExpr GhcRn)
exp) [LHsRecUpdProj GhcRn]
[GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
      (GenLocated SrcSpanAnnA (HsExpr GhcRn)))]
updates
  where
    fieldUpdate :: HsExpr GhcRn -> LHsRecUpdProj GhcRn -> HsExpr GhcRn
    fieldUpdate :: HsExpr GhcRn -> LHsRecUpdProj GhcRn -> HsExpr GhcRn
fieldUpdate HsExpr GhcRn
acc LHsRecUpdProj GhcRn
lpu =  GenLocated SrcSpanAnnA (HsExpr GhcRn) -> HsExpr GhcRn
forall l e. GenLocated l e -> e
unLoc (GenLocated SrcSpanAnnA (HsExpr GhcRn) -> HsExpr GhcRn)
-> GenLocated SrcSpanAnnA (HsExpr GhcRn) -> HsExpr GhcRn
forall a b. (a -> b) -> a -> b
$ (Name
-> Name
-> LHsRecUpdProj GhcRn
-> XRec GhcRn (HsExpr GhcRn)
-> XRec GhcRn (HsExpr GhcRn)
mkProjUpdateSetField Name
get_field Name
set_field LHsRecUpdProj GhcRn
lpu) (HsExpr GhcRn -> GenLocated SrcSpanAnnA (HsExpr GhcRn)
forall an a. NoAnn an => a -> LocatedAn an a
wrapGenSpan HsExpr GhcRn
acc)

rnHsUpdProjs :: [LHsRecUpdProj GhcPs] -> RnM ([LHsRecUpdProj GhcRn], FreeVars)
rnHsUpdProjs :: [LHsRecUpdProj GhcPs] -> RnM ([LHsRecUpdProj GhcRn], FreeVars)
rnHsUpdProjs [LHsRecUpdProj GhcPs]
us = do
  (u, fvs) <- [(GenLocated
    SrcSpanAnnA
    (HsFieldBind
       (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
       (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
  FreeVars)]
-> ([GenLocated
       SrcSpanAnnA
       (HsFieldBind
          (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
          (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
    [FreeVars])
forall a b. [(a, b)] -> ([a], [b])
unzip ([(GenLocated
     SrcSpanAnnA
     (HsFieldBind
        (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
        (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
   FreeVars)]
 -> ([GenLocated
        SrcSpanAnnA
        (HsFieldBind
           (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
           (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
     [FreeVars]))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA
         (HsFieldBind
            (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
            (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     ([GenLocated
         SrcSpanAnnA
         (HsFieldBind
            (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
            (GenLocated SrcSpanAnnA (HsExpr GhcRn)))],
      [FreeVars])
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
      (GenLocated SrcSpanAnnA (HsExpr GhcPs)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (GenLocated
         SrcSpanAnnA
         (HsFieldBind
            (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
            (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars))
-> [GenLocated
      SrcSpanAnnA
      (HsFieldBind
         (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
         (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(GenLocated
         SrcSpanAnnA
         (HsFieldBind
            (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
            (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
       FreeVars)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
forall (m :: * -> *) a b. Monad m => (a -> m b) -> [a] -> m [b]
mapM LHsRecUpdProj GhcPs -> RnM (LHsRecUpdProj GhcRn, FreeVars)
GenLocated
  SrcSpanAnnA
  (HsFieldBind
     (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
     (GenLocated SrcSpanAnnA (HsExpr GhcPs)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpanAnnA
        (HsFieldBind
           (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcRn))
           (GenLocated SrcSpanAnnA (HsExpr GhcRn))),
      FreeVars)
rnRecUpdProj [LHsRecUpdProj GhcPs]
[GenLocated
   SrcSpanAnnA
   (HsFieldBind
      (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
      (GenLocated SrcSpanAnnA (HsExpr GhcPs)))]
us
  pure (u, plusFVs fvs)
  where
    rnRecUpdProj :: LHsRecUpdProj GhcPs -> RnM (LHsRecUpdProj GhcRn, FreeVars)
    rnRecUpdProj :: LHsRecUpdProj GhcPs -> RnM (LHsRecUpdProj GhcRn, FreeVars)
rnRecUpdProj (L SrcSpanAnnA
l (HsFieldBind XHsFieldBind
  (GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs))
_ GenLocated (EpAnn NoEpAnns) (FieldLabelStrings GhcPs)
fs GenLocated SrcSpanAnnA (HsExpr GhcPs)
arg Bool
pun))
      = do { (arg, fv) <- LHsExpr GhcPs -> RnM (XRec GhcRn (HsExpr GhcRn), FreeVars)
rnLExpr LHsExpr GhcPs
GenLocated SrcSpanAnnA (HsExpr GhcPs)
arg
           ; return $
               (L l (HsFieldBind {
                         hfbAnn = noAnn
                       , hfbLHS = fmap rnFieldLabelStrings fs
                       , hfbRHS = arg
                       , hfbPun = pun }), fv ) }