{-# LANGUAGE CPP                 #-}
{-# LANGUAGE DataKinds           #-}
{-# LANGUAGE FlexibleContexts    #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections       #-}
{-# LANGUAGE TypeFamilies        #-}
{-# LANGUAGE UndecidableInstances #-} -- Wrinkle in Note [Trees That Grow]
                                      -- in module GHC.Hs.Extension
{-# OPTIONS_GHC -Wno-incomplete-uni-patterns   #-}

{-
%
(c) The University of Glasgow 2006
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998

-}

module GHC.Tc.Gen.Expr
       ( tcCheckPolyExpr, tcCheckPolyExprNC,
         tcCheckMonoExpr, tcCheckMonoExprNC, tcMonoExpr, tcMonoExprNC,
         tcInferRho, tcInferRhoNC,
         tcExpr,
         tcSyntaxOp, tcSyntaxOpGen, SyntaxOpType(..), synKnownType,
         tcCheckId,
         addAmbiguousNameErr,
         getFixedTyVars ) where

#include "GhclibHsVersions.h"

import GHC.Prelude

import {-# SOURCE #-}   GHC.Tc.Gen.Splice( tcSpliceExpr, tcTypedBracket, tcUntypedBracket )

import GHC.Hs
import GHC.Rename.Utils
import GHC.Tc.Utils.Zonk
import GHC.Tc.Utils.Monad
import GHC.Tc.Utils.Unify
import GHC.Types.Basic
import GHC.Types.SourceText
import GHC.Core.Multiplicity
import GHC.Core.UsageEnv
import GHC.Tc.Utils.Instantiate
import GHC.Tc.Gen.App
import GHC.Tc.Gen.Head
import GHC.Tc.Gen.Bind        ( tcLocalBinds )
import GHC.Tc.Instance.Family ( tcGetFamInstEnvs )
import GHC.Core.FamInstEnv    ( FamInstEnvs )
import GHC.Rename.Env         ( addUsedGRE )
import GHC.Tc.Utils.Env
import GHC.Tc.Gen.Arrow
import GHC.Tc.Gen.Match
import GHC.Tc.Gen.HsType
import GHC.Tc.Gen.Pat
import GHC.Tc.Utils.TcMType
import GHC.Tc.Types.Origin
import GHC.Tc.Utils.TcType as TcType
import GHC.Types.Id
import GHC.Types.Id.Info
import GHC.Core.ConLike
import GHC.Core.DataCon
import GHC.Core.PatSyn
import GHC.Types.Name
import GHC.Types.Name.Env
import GHC.Types.Name.Set
import GHC.Types.Name.Reader
import GHC.Core.TyCon
import GHC.Core.Type
import GHC.Tc.Types.Evidence
import GHC.Types.Var.Set
import GHC.Builtin.Types
import GHC.Builtin.Names
import GHC.Driver.Session
import GHC.Types.SrcLoc
import GHC.Utils.Misc
import GHC.Data.List.SetOps
import GHC.Data.Maybe
import GHC.Utils.Outputable as Outputable
import GHC.Utils.Panic
import GHC.Data.FastString
import Control.Monad
import GHC.Core.Class(classTyCon)
import GHC.Types.Unique.Set ( UniqSet, mkUniqSet, elementOfUniqSet, nonDetEltsUniqSet )
import qualified GHC.LanguageExtensions as LangExt

import Data.Function
import Data.List (partition, sortBy, groupBy, intersect)

{-
************************************************************************
*                                                                      *
\subsection{Main wrappers}
*                                                                      *
************************************************************************
-}


tcCheckPolyExpr, tcCheckPolyExprNC
  :: LHsExpr GhcRn         -- Expression to type check
  -> TcSigmaType           -- Expected type (could be a polytype)
  -> TcM (LHsExpr GhcTc) -- Generalised expr with expected type

-- tcCheckPolyExpr is a convenient place (frequent but not too frequent)
-- place to add context information.
-- The NC version does not do so, usually because the caller wants
-- to do so themselves.

tcCheckPolyExpr :: LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr   LHsExpr GhcRn
expr TcSigmaType
res_ty = LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcPolyExpr   LHsExpr GhcRn
expr (TcSigmaType -> ExpSigmaType
mkCheckExpType TcSigmaType
res_ty)
tcCheckPolyExprNC :: LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExprNC LHsExpr GhcRn
expr TcSigmaType
res_ty = LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcPolyExprNC LHsExpr GhcRn
expr (TcSigmaType -> ExpSigmaType
mkCheckExpType TcSigmaType
res_ty)

-- These versions take an ExpType
tcPolyExpr, tcPolyExprNC
  :: LHsExpr GhcRn -> ExpSigmaType
  -> TcM (LHsExpr GhcTc)

tcPolyExpr :: LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcPolyExpr LHsExpr GhcRn
expr ExpSigmaType
res_ty
  = LHsExpr GhcRn
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. LHsExpr GhcRn -> TcRn a -> TcRn a
addLExprCtxt LHsExpr GhcRn
expr (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$
    do { String -> SDoc -> TcRn ()
traceTc String
"tcPolyExpr" (ExpSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr ExpSigmaType
res_ty)
       ; LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcPolyExprNC LHsExpr GhcRn
expr ExpSigmaType
res_ty }

tcPolyExprNC :: LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcPolyExprNC (L loc expr) ExpSigmaType
res_ty
  = SrcSpan
-> HsExpr GhcRn
-> TcRn (Located (HsExpr GhcTc))
-> TcRn (Located (HsExpr GhcTc))
forall a. SrcSpan -> HsExpr GhcRn -> TcRn a -> TcRn a
set_loc_and_ctxt SrcSpan
loc HsExpr GhcRn
expr (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$
    do { String -> SDoc -> TcRn ()
traceTc String
"tcPolyExprNC" (ExpSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr ExpSigmaType
res_ty)
       ; (HsWrapper
wrap, HsExpr GhcTc
expr') <- UserTypeCtxt
-> ExpSigmaType
-> (ExpSigmaType -> TcM (HsExpr GhcTc))
-> TcM (HsWrapper, HsExpr GhcTc)
forall result.
UserTypeCtxt
-> ExpSigmaType
-> (ExpSigmaType -> TcM result)
-> TcM (HsWrapper, result)
tcSkolemiseET UserTypeCtxt
GenSigCtxt ExpSigmaType
res_ty ((ExpSigmaType -> TcM (HsExpr GhcTc))
 -> TcM (HsWrapper, HsExpr GhcTc))
-> (ExpSigmaType -> TcM (HsExpr GhcTc))
-> TcM (HsWrapper, HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ \ ExpSigmaType
res_ty ->
                          HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr HsExpr GhcRn
expr ExpSigmaType
res_ty
       ; Located (HsExpr GhcTc) -> TcRn (Located (HsExpr GhcTc))
forall (m :: * -> *) a. Monad m => a -> m a
return (Located (HsExpr GhcTc) -> TcRn (Located (HsExpr GhcTc)))
-> Located (HsExpr GhcTc) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ SrcSpan -> HsExpr GhcTc -> Located (HsExpr GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap HsExpr GhcTc
expr') }

  where -- See Note [Rebindable syntax and HsExpansion), which describes
        -- the logic behind this location/context tweaking.
        set_loc_and_ctxt :: SrcSpan -> HsExpr GhcRn -> TcRn a -> TcRn a
set_loc_and_ctxt SrcSpan
l HsExpr GhcRn
e TcRn a
m = do
          Bool
inGenCode <- TcRn Bool
inGeneratedCode
          if Bool
inGenCode Bool -> Bool -> Bool
&& Bool -> Bool
not (SrcSpan -> Bool
isGeneratedSrcSpan SrcSpan
l)
            then SrcSpan -> TcRn a -> TcRn a
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
l (TcRn a -> TcRn a) -> TcRn a -> TcRn a
forall a b. (a -> b) -> a -> b
$
                 HsExpr GhcRn -> TcRn a -> TcRn a
forall a. HsExpr GhcRn -> TcRn a -> TcRn a
addExprCtxt HsExpr GhcRn
e TcRn a
m
            else SrcSpan -> TcRn a -> TcRn a
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
l TcRn a
m

---------------
tcCheckMonoExpr, tcCheckMonoExprNC
    :: LHsExpr GhcRn     -- Expression to type check
    -> TcRhoType         -- Expected type
                         -- Definitely no foralls at the top
    -> TcM (LHsExpr GhcTc)
tcCheckMonoExpr :: LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckMonoExpr   LHsExpr GhcRn
expr TcSigmaType
res_ty = LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExpr   LHsExpr GhcRn
expr (TcSigmaType -> ExpSigmaType
mkCheckExpType TcSigmaType
res_ty)
tcCheckMonoExprNC :: LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckMonoExprNC LHsExpr GhcRn
expr TcSigmaType
res_ty = LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExprNC LHsExpr GhcRn
expr (TcSigmaType -> ExpSigmaType
mkCheckExpType TcSigmaType
res_ty)

tcMonoExpr, tcMonoExprNC
    :: LHsExpr GhcRn     -- Expression to type check
    -> ExpRhoType        -- Expected type
                         -- Definitely no foralls at the top
    -> TcM (LHsExpr GhcTc)

tcMonoExpr :: LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExpr LHsExpr GhcRn
expr ExpSigmaType
res_ty
  = LHsExpr GhcRn
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. LHsExpr GhcRn -> TcRn a -> TcRn a
addLExprCtxt LHsExpr GhcRn
expr (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$
    LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExprNC LHsExpr GhcRn
expr ExpSigmaType
res_ty

tcMonoExprNC :: LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExprNC (L loc expr) ExpSigmaType
res_ty
  = SrcSpan
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
loc (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$
    do  { HsExpr GhcTc
expr' <- HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr HsExpr GhcRn
expr ExpSigmaType
res_ty
        ; Located (HsExpr GhcTc) -> TcRn (Located (HsExpr GhcTc))
forall (m :: * -> *) a. Monad m => a -> m a
return (SrcSpan -> HsExpr GhcTc -> Located (HsExpr GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc HsExpr GhcTc
expr') }

---------------
tcInferRho, tcInferRhoNC :: LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcRhoType)
-- Infer a *rho*-type. The return type is always instantiated.
tcInferRho :: LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRho LHsExpr GhcRn
le = LHsExpr GhcRn
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a. LHsExpr GhcRn -> TcRn a -> TcRn a
addLExprCtxt LHsExpr GhcRn
le (TcRn (Located (HsExpr GhcTc), TcSigmaType)
 -> TcRn (Located (HsExpr GhcTc), TcSigmaType))
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a b. (a -> b) -> a -> b
$
                LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRhoNC LHsExpr GhcRn
le

tcInferRhoNC :: LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRhoNC (L loc expr)
  = SrcSpan
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
loc (TcRn (Located (HsExpr GhcTc), TcSigmaType)
 -> TcRn (Located (HsExpr GhcTc), TcSigmaType))
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a b. (a -> b) -> a -> b
$
    do { (HsExpr GhcTc
expr', TcSigmaType
rho) <- (ExpSigmaType -> TcM (HsExpr GhcTc))
-> TcM (HsExpr GhcTc, TcSigmaType)
forall a. (ExpSigmaType -> TcM a) -> TcM (a, TcSigmaType)
tcInfer (HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr HsExpr GhcRn
expr)
       ; (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall (m :: * -> *) a. Monad m => a -> m a
return (SrcSpan -> HsExpr GhcTc -> Located (HsExpr GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc HsExpr GhcTc
expr', TcSigmaType
rho) }


{- *********************************************************************
*                                                                      *
        tcExpr: the main expression typechecker
*                                                                      *
********************************************************************* -}

tcExpr :: HsExpr GhcRn -> ExpRhoType -> TcM (HsExpr GhcTc)

-- Use tcApp to typecheck appplications, which are treated specially
-- by Quick Look.  Specifically:
--   - HsApp:     value applications
--   - HsTypeApp: type applications
--   - HsVar:     lone variables, to ensure that they can get an
--                impredicative instantiation (via Quick Look
--                driven by res_ty (in checking mode).
--   - ExprWithTySig: (e :: type)
-- See Note [Application chains and heads] in GHC.Tc.Gen.App
tcExpr :: HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr e :: HsExpr GhcRn
e@(HsVar {})         ExpSigmaType
res_ty = HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcApp HsExpr GhcRn
e ExpSigmaType
res_ty
tcExpr e :: HsExpr GhcRn
e@(HsApp {})         ExpSigmaType
res_ty = HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcApp HsExpr GhcRn
e ExpSigmaType
res_ty
tcExpr e :: HsExpr GhcRn
e@(HsAppType {})     ExpSigmaType
res_ty = HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcApp HsExpr GhcRn
e ExpSigmaType
res_ty
tcExpr e :: HsExpr GhcRn
e@(ExprWithTySig {}) ExpSigmaType
res_ty = HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcApp HsExpr GhcRn
e ExpSigmaType
res_ty
tcExpr e :: HsExpr GhcRn
e@(HsRecFld {})      ExpSigmaType
res_ty = HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcApp HsExpr GhcRn
e ExpSigmaType
res_ty

-- Typecheck an occurrence of an unbound Id
--
-- Some of these started life as a true expression hole "_".
-- Others might simply be variables that accidentally have no binding site
tcExpr e :: HsExpr GhcRn
e@(HsUnboundVar XUnboundVar GhcRn
_ OccName
occ) ExpSigmaType
res_ty
  = do { TcSigmaType
ty <- TcM TcSigmaType
newOpenFlexiTyVarTy  -- Allow Int# etc (#12531)
       ; Name
name <- OccName -> TcRnIf TcGblEnv TcLclEnv Name
forall gbl lcl. OccName -> TcRnIf gbl lcl Name
newSysName OccName
occ
       ; let ev :: Id
ev = HasDebugCallStack => Name -> TcSigmaType -> TcSigmaType -> Id
Name -> TcSigmaType -> TcSigmaType -> Id
mkLocalId Name
name TcSigmaType
Many TcSigmaType
ty
       ; OccName -> Id -> TcSigmaType -> TcRn ()
emitNewExprHole OccName
occ Id
ev TcSigmaType
ty
       ; UsageEnv -> TcRn ()
tcEmitBindingUsage UsageEnv
bottomUE   -- Holes fit any usage environment
                                       -- (#18491)
       ; CtOrigin
-> HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResultO (OccName -> CtOrigin
UnboundOccurrenceOf OccName
occ) HsExpr GhcRn
e
                       (XUnboundVar GhcTc -> OccName -> HsExpr GhcTc
forall p. XUnboundVar p -> OccName -> HsExpr p
HsUnboundVar Id
XUnboundVar GhcTc
ev OccName
occ) TcSigmaType
ty ExpSigmaType
res_ty }

tcExpr e :: HsExpr GhcRn
e@(HsLit XLitE GhcRn
x HsLit GhcRn
lit) ExpSigmaType
res_ty
  = do { let lit_ty :: TcSigmaType
lit_ty = HsLit GhcRn -> TcSigmaType
forall (p :: Pass). HsLit (GhcPass p) -> TcSigmaType
hsLitType HsLit GhcRn
lit
       ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResult HsExpr GhcRn
e (XLitE GhcTc -> HsLit GhcTc -> HsExpr GhcTc
forall p. XLitE p -> HsLit p -> HsExpr p
HsLit XLitE GhcRn
XLitE GhcTc
x (HsLit GhcRn -> HsLit GhcTc
forall (p1 :: Pass) (p2 :: Pass).
HsLit (GhcPass p1) -> HsLit (GhcPass p2)
convertLit HsLit GhcRn
lit)) TcSigmaType
lit_ty ExpSigmaType
res_ty }

tcExpr (HsPar XPar GhcRn
x LHsExpr GhcRn
expr) ExpSigmaType
res_ty
  = do { Located (HsExpr GhcTc)
expr' <- LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExprNC LHsExpr GhcRn
expr ExpSigmaType
res_ty
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XPar GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XPar p -> LHsExpr p -> HsExpr p
HsPar XPar GhcRn
XPar GhcTc
x Located (HsExpr GhcTc)
LHsExpr GhcTc
expr') }

tcExpr (HsPragE XPragE GhcRn
x HsPragE GhcRn
prag LHsExpr GhcRn
expr) ExpSigmaType
res_ty
  = do { Located (HsExpr GhcTc)
expr' <- LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExpr LHsExpr GhcRn
expr ExpSigmaType
res_ty
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XPragE GhcTc -> HsPragE GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XPragE p -> HsPragE p -> LHsExpr p -> HsExpr p
HsPragE XPragE GhcRn
XPragE GhcTc
x (HsPragE GhcRn -> HsPragE GhcTc
tcExprPrag HsPragE GhcRn
prag) Located (HsExpr GhcTc)
LHsExpr GhcTc
expr') }

tcExpr (HsOverLit XOverLitE GhcRn
x HsOverLit GhcRn
lit) ExpSigmaType
res_ty
  = do  { HsOverLit GhcTc
lit' <- HsOverLit GhcRn -> ExpSigmaType -> TcM (HsOverLit GhcTc)
newOverloadedLit HsOverLit GhcRn
lit ExpSigmaType
res_ty
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XOverLitE GhcTc -> HsOverLit GhcTc -> HsExpr GhcTc
forall p. XOverLitE p -> HsOverLit p -> HsExpr p
HsOverLit XOverLitE GhcRn
XOverLitE GhcTc
x HsOverLit GhcTc
lit') }

tcExpr (NegApp XNegApp GhcRn
x LHsExpr GhcRn
expr SyntaxExpr GhcRn
neg_expr) ExpSigmaType
res_ty
  = do  { (Located (HsExpr GhcTc)
expr', SyntaxExprTc
neg_expr')
            <- CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcRn (Located (HsExpr GhcTc)))
-> TcM (Located (HsExpr GhcTc), SyntaxExprTc)
forall a.
CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
tcSyntaxOp CtOrigin
NegateOrigin SyntaxExprRn
SyntaxExpr GhcRn
neg_expr [SyntaxOpType
SynAny] ExpSigmaType
res_ty (([TcSigmaType] -> [TcSigmaType] -> TcRn (Located (HsExpr GhcTc)))
 -> TcM (Located (HsExpr GhcTc), SyntaxExprTc))
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcRn (Located (HsExpr GhcTc)))
-> TcM (Located (HsExpr GhcTc), SyntaxExprTc)
forall a b. (a -> b) -> a -> b
$
               \[TcSigmaType
arg_ty] [TcSigmaType
arg_mult] ->
               TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
arg_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckMonoExpr LHsExpr GhcRn
expr TcSigmaType
arg_ty
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XNegApp GhcTc -> LHsExpr GhcTc -> SyntaxExpr GhcTc -> HsExpr GhcTc
forall p. XNegApp p -> LHsExpr p -> SyntaxExpr p -> HsExpr p
NegApp XNegApp GhcRn
XNegApp GhcTc
x Located (HsExpr GhcTc)
LHsExpr GhcTc
expr' SyntaxExprTc
SyntaxExpr GhcTc
neg_expr') }

tcExpr e :: HsExpr GhcRn
e@(HsIPVar XIPVar GhcRn
_ HsIPName
x) ExpSigmaType
res_ty
  = do {   {- Implicit parameters must have a *tau-type* not a
              type scheme.  We enforce this by creating a fresh
              type variable as its type.  (Because res_ty may not
              be a tau-type.) -}
         TcSigmaType
ip_ty <- TcM TcSigmaType
newOpenFlexiTyVarTy
       ; let ip_name :: TcSigmaType
ip_name = FastString -> TcSigmaType
mkStrLitTy (HsIPName -> FastString
hsIPNameFS HsIPName
x)
       ; Class
ipClass <- Name -> TcM Class
tcLookupClass Name
ipClassName
       ; Id
ip_var <- CtOrigin -> TcSigmaType -> TcM Id
emitWantedEvVar CtOrigin
origin (Class -> [TcSigmaType] -> TcSigmaType
mkClassPred Class
ipClass [TcSigmaType
ip_name, TcSigmaType
ip_ty])
       ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResult HsExpr GhcRn
e
                   (Class -> TcSigmaType -> TcSigmaType -> HsExpr GhcTc -> HsExpr GhcTc
fromDict Class
ipClass TcSigmaType
ip_name TcSigmaType
ip_ty (XVar GhcTc -> LIdP GhcTc -> HsExpr GhcTc
forall p. XVar p -> LIdP p -> HsExpr p
HsVar NoExtField
XVar GhcTc
noExtField (Id -> Located Id
forall e. e -> Located e
noLoc Id
ip_var)))
                   TcSigmaType
ip_ty ExpSigmaType
res_ty }
  where
  -- Coerces a dictionary for `IP "x" t` into `t`.
  fromDict :: Class -> TcSigmaType -> TcSigmaType -> HsExpr GhcTc -> HsExpr GhcTc
fromDict Class
ipClass TcSigmaType
x TcSigmaType
ty = HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap (HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc)
-> HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$ TcCoercionR -> HsWrapper
mkWpCastR (TcCoercionR -> HsWrapper) -> TcCoercionR -> HsWrapper
forall a b. (a -> b) -> a -> b
$
                          TcSigmaType -> TcCoercionR
unwrapIP (TcSigmaType -> TcCoercionR) -> TcSigmaType -> TcCoercionR
forall a b. (a -> b) -> a -> b
$ Class -> [TcSigmaType] -> TcSigmaType
mkClassPred Class
ipClass [TcSigmaType
x,TcSigmaType
ty]
  origin :: CtOrigin
origin = HsIPName -> CtOrigin
IPOccOrigin HsIPName
x

tcExpr e :: HsExpr GhcRn
e@(HsOverLabel XOverLabel GhcRn
_ Maybe (IdP GhcRn)
mb_fromLabel FastString
l) ExpSigmaType
res_ty
  = do { -- See Note [Type-checking overloaded labels]
         SrcSpan
loc <- TcRn SrcSpan
getSrcSpanM
       ; case Maybe (IdP GhcRn)
mb_fromLabel of
           Just IdP GhcRn
fromLabel -> HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr (SrcSpan -> Name -> HsExpr GhcRn
applyFromLabel SrcSpan
loc Name
IdP GhcRn
fromLabel) ExpSigmaType
res_ty
           Maybe (IdP GhcRn)
Nothing -> do { Class
isLabelClass <- Name -> TcM Class
tcLookupClass Name
isLabelClassName
                         ; TcSigmaType
alpha <- TcSigmaType -> TcM TcSigmaType
newFlexiTyVarTy TcSigmaType
liftedTypeKind
                         ; let pred :: TcSigmaType
pred = Class -> [TcSigmaType] -> TcSigmaType
mkClassPred Class
isLabelClass [TcSigmaType
lbl, TcSigmaType
alpha]
                         ; SrcSpan
loc <- TcRn SrcSpan
getSrcSpanM
                         ; Id
var <- CtOrigin -> TcSigmaType -> TcM Id
emitWantedEvVar CtOrigin
origin TcSigmaType
pred
                         ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResult HsExpr GhcRn
e
                                       (TcSigmaType -> HsExpr GhcTc -> HsExpr GhcTc
fromDict TcSigmaType
pred (XVar GhcTc -> LIdP GhcTc -> HsExpr GhcTc
forall p. XVar p -> LIdP p -> HsExpr p
HsVar NoExtField
XVar GhcTc
noExtField (SrcSpan -> Id -> Located Id
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc Id
var)))
                                        TcSigmaType
alpha ExpSigmaType
res_ty } }
  where
  -- Coerces a dictionary for `IsLabel "x" t` into `t`,
  -- or `HasField "x" r a into `r -> a`.
  fromDict :: TcSigmaType -> HsExpr GhcTc -> HsExpr GhcTc
fromDict TcSigmaType
pred = HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap (HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc)
-> HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$ TcCoercionR -> HsWrapper
mkWpCastR (TcCoercionR -> HsWrapper) -> TcCoercionR -> HsWrapper
forall a b. (a -> b) -> a -> b
$ TcSigmaType -> TcCoercionR
unwrapIP TcSigmaType
pred
  origin :: CtOrigin
origin = FastString -> CtOrigin
OverLabelOrigin FastString
l
  lbl :: TcSigmaType
lbl = FastString -> TcSigmaType
mkStrLitTy FastString
l

  applyFromLabel :: SrcSpan -> Name -> HsExpr GhcRn
applyFromLabel SrcSpan
loc Name
fromLabel =
    XAppTypeE GhcRn
-> LHsExpr GhcRn -> LHsWcType (NoGhcTc GhcRn) -> HsExpr GhcRn
forall p.
XAppTypeE p -> LHsExpr p -> LHsWcType (NoGhcTc p) -> HsExpr p
HsAppType NoExtField
XAppTypeE GhcRn
noExtField
         (SrcSpan -> HsExpr GhcRn -> GenLocated SrcSpan (HsExpr GhcRn)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XVar GhcRn -> LIdP GhcRn -> HsExpr GhcRn
forall p. XVar p -> LIdP p -> HsExpr p
HsVar NoExtField
XVar GhcRn
noExtField (SrcSpan -> Name -> GenLocated SrcSpan Name
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc Name
fromLabel)))
         (GenLocated SrcSpan (HsType GhcRn)
-> HsWildCardBndrs GhcRn (GenLocated SrcSpan (HsType GhcRn))
forall thing. thing -> HsWildCardBndrs GhcRn thing
mkEmptyWildCardBndrs (SrcSpan -> HsType GhcRn -> GenLocated SrcSpan (HsType GhcRn)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XTyLit GhcRn -> HsTyLit -> HsType GhcRn
forall pass. XTyLit pass -> HsTyLit -> HsType pass
HsTyLit NoExtField
XTyLit GhcRn
noExtField (SourceText -> FastString -> HsTyLit
HsStrTy SourceText
NoSourceText FastString
l))))

tcExpr (HsLam XLam GhcRn
x MatchGroup GhcRn (LHsExpr GhcRn)
match) ExpSigmaType
res_ty
  = do  { (HsWrapper
wrap, MatchGroup GhcTc (Located (HsExpr GhcTc))
match') <- SDoc
-> TcMatchCtxt HsExpr
-> MatchGroup GhcRn (LHsExpr GhcRn)
-> ExpSigmaType
-> TcM (HsWrapper, MatchGroup GhcTc (LHsExpr GhcTc))
tcMatchLambda SDoc
herald TcMatchCtxt HsExpr
match_ctxt MatchGroup GhcRn (LHsExpr GhcRn)
match ExpSigmaType
res_ty
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap (XLam GhcTc -> MatchGroup GhcTc (LHsExpr GhcTc) -> HsExpr GhcTc
forall p. XLam p -> MatchGroup p (LHsExpr p) -> HsExpr p
HsLam XLam GhcRn
XLam GhcTc
x MatchGroup GhcTc (Located (HsExpr GhcTc))
MatchGroup GhcTc (LHsExpr GhcTc)
match')) }
  where
    match_ctxt :: TcMatchCtxt HsExpr
match_ctxt = MC :: forall (body :: * -> *).
HsMatchContext GhcRn
-> (Located (body GhcRn)
    -> ExpSigmaType -> TcM (Located (body GhcTc)))
-> TcMatchCtxt body
MC { mc_what :: HsMatchContext GhcRn
mc_what = HsMatchContext GhcRn
forall p. HsMatchContext p
LambdaExpr, mc_body :: GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
mc_body = GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcBody }
    herald :: SDoc
herald = [SDoc] -> SDoc
sep [ String -> SDoc
text String
"The lambda expression" SDoc -> SDoc -> SDoc
<+>
                   SDoc -> SDoc
quotes (Depth -> SDoc -> SDoc
pprSetDepth (Int -> Depth
PartWay Int
1) (SDoc -> SDoc) -> SDoc -> SDoc
forall a b. (a -> b) -> a -> b
$
                           MatchGroup GhcRn (GenLocated SrcSpan (HsExpr GhcRn)) -> SDoc
forall (idR :: Pass) body.
(OutputableBndrId idR, Outputable body) =>
MatchGroup (GhcPass idR) body -> SDoc
pprMatches MatchGroup GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
MatchGroup GhcRn (LHsExpr GhcRn)
match),
                        -- The pprSetDepth makes the abstraction print briefly
                   String -> SDoc
text String
"has"]

tcExpr e :: HsExpr GhcRn
e@(HsLamCase XLamCase GhcRn
x MatchGroup GhcRn (LHsExpr GhcRn)
matches) ExpSigmaType
res_ty
  = do { (HsWrapper
wrap, MatchGroup GhcTc (Located (HsExpr GhcTc))
matches')
           <- SDoc
-> TcMatchCtxt HsExpr
-> MatchGroup GhcRn (LHsExpr GhcRn)
-> ExpSigmaType
-> TcM (HsWrapper, MatchGroup GhcTc (LHsExpr GhcTc))
tcMatchLambda SDoc
msg TcMatchCtxt HsExpr
match_ctxt MatchGroup GhcRn (LHsExpr GhcRn)
matches ExpSigmaType
res_ty
           -- The laziness annotation is because we don't want to fail here
           -- if there are multiple arguments
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$ XLamCase GhcTc -> MatchGroup GhcTc (LHsExpr GhcTc) -> HsExpr GhcTc
forall p. XLamCase p -> MatchGroup p (LHsExpr p) -> HsExpr p
HsLamCase XLamCase GhcRn
XLamCase GhcTc
x MatchGroup GhcTc (Located (HsExpr GhcTc))
MatchGroup GhcTc (LHsExpr GhcTc)
matches') }
  where
    msg :: SDoc
msg = [SDoc] -> SDoc
sep [ String -> SDoc
text String
"The function" SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (HsExpr GhcRn -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcRn
e)
              , String -> SDoc
text String
"requires"]
    match_ctxt :: TcMatchCtxt HsExpr
match_ctxt = MC :: forall (body :: * -> *).
HsMatchContext GhcRn
-> (Located (body GhcRn)
    -> ExpSigmaType -> TcM (Located (body GhcTc)))
-> TcMatchCtxt body
MC { mc_what :: HsMatchContext GhcRn
mc_what = HsMatchContext GhcRn
forall p. HsMatchContext p
CaseAlt, mc_body :: GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
mc_body = GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcBody }

{-
Note [Type-checking overloaded labels]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Recall that we have

  module GHC.OverloadedLabels where
    class IsLabel (x :: Symbol) a where
      fromLabel :: a

We translate `#foo` to `fromLabel @"foo"`, where we use

 * the in-scope `fromLabel` if `RebindableSyntax` is enabled; or if not
 * `GHC.OverloadedLabels.fromLabel`.

In the `RebindableSyntax` case, the renamer will have filled in the
first field of `HsOverLabel` with the `fromLabel` function to use, and
we simply apply it to the appropriate visible type argument.

In the `OverloadedLabels` case, when we see an overloaded label like
`#foo`, we generate a fresh variable `alpha` for the type and emit an
`IsLabel "foo" alpha` constraint.  Because the `IsLabel` class has a
single method, it is represented by a newtype, so we can coerce
`IsLabel "foo" alpha` to `alpha` (just like for implicit parameters).

-}


{-
************************************************************************
*                                                                      *
                Infix operators and sections
*                                                                      *
************************************************************************

Note [Left sections]
~~~~~~~~~~~~~~~~~~~~
Left sections, like (4 *), are equivalent to
        \ x -> (*) 4 x,
or, if PostfixOperators is enabled, just
        (*) 4
With PostfixOperators we don't actually require the function to take
two arguments at all.  For example, (x `not`) means (not x); you get
postfix operators!  Not Haskell 98, but it's less work and kind of
useful.
-}

tcExpr expr :: HsExpr GhcRn
expr@(OpApp {}) ExpSigmaType
res_ty
  = HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcApp HsExpr GhcRn
expr ExpSigmaType
res_ty

-- Right sections, equivalent to \ x -> x `op` expr, or
--      \ x -> op x expr

tcExpr expr :: HsExpr GhcRn
expr@(SectionR XSectionR GhcRn
x LHsExpr GhcRn
op LHsExpr GhcRn
arg2) ExpSigmaType
res_ty
  = do { (Located (HsExpr GhcTc)
op', TcSigmaType
op_ty) <- LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRhoNC LHsExpr GhcRn
op
       ; (HsWrapper
wrap_fun, [Scaled TcSigmaType
arg1_mult TcSigmaType
arg1_ty, Scaled TcSigmaType
arg2_ty], TcSigmaType
op_res_ty)
                  <- SDoc
-> CtOrigin
-> Maybe SDoc
-> Int
-> TcSigmaType
-> TcM (HsWrapper, [Scaled TcSigmaType], TcSigmaType)
matchActualFunTysRho (LHsExpr GhcRn -> SDoc
mk_op_msg LHsExpr GhcRn
op) CtOrigin
fn_orig
                                          (SDoc -> Maybe SDoc
forall a. a -> Maybe a
Just (GenLocated SrcSpan (HsExpr GhcRn) -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
op)) Int
2 TcSigmaType
op_ty
       ; Located (HsExpr GhcTc)
arg2' <- HsExpr GhcRn
-> LHsExpr GhcRn
-> Scaled TcSigmaType
-> Int
-> TcM (LHsExpr GhcTc)
tcValArg (GenLocated SrcSpan (HsExpr GhcRn) -> HsExpr GhcRn
forall l e. GenLocated l e -> e
unLoc GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
op) LHsExpr GhcRn
arg2 Scaled TcSigmaType
arg2_ty Int
2
       ; let expr' :: HsExpr GhcTc
expr'      = XSectionR GhcTc -> LHsExpr GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XSectionR p -> LHsExpr p -> LHsExpr p -> HsExpr p
SectionR XSectionR GhcRn
XSectionR GhcTc
x (HsWrapper -> LHsExpr GhcTc -> LHsExpr GhcTc
mkLHsWrap HsWrapper
wrap_fun Located (HsExpr GhcTc)
LHsExpr GhcTc
op') Located (HsExpr GhcTc)
LHsExpr GhcTc
arg2'
             act_res_ty :: TcSigmaType
act_res_ty = TcSigmaType -> TcSigmaType -> TcSigmaType -> TcSigmaType
mkVisFunTy TcSigmaType
arg1_mult TcSigmaType
arg1_ty TcSigmaType
op_res_ty
       ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResultMono HsExpr GhcRn
expr HsExpr GhcTc
expr' TcSigmaType
act_res_ty ExpSigmaType
res_ty }

  where
    fn_orig :: CtOrigin
fn_orig = LHsExpr GhcRn -> CtOrigin
lexprCtOrigin LHsExpr GhcRn
op
    -- It's important to use the origin of 'op', so that call-stacks
    -- come out right; they are driven by the OccurrenceOf CtOrigin
    -- See #13285

tcExpr expr :: HsExpr GhcRn
expr@(SectionL XSectionL GhcRn
x LHsExpr GhcRn
arg1 LHsExpr GhcRn
op) ExpSigmaType
res_ty
  = do { (Located (HsExpr GhcTc)
op', TcSigmaType
op_ty) <- LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRhoNC LHsExpr GhcRn
op
       ; DynFlags
dflags <- IOEnv (Env TcGblEnv TcLclEnv) DynFlags
forall (m :: * -> *). HasDynFlags m => m DynFlags
getDynFlags      -- Note [Left sections]
       ; let n_reqd_args :: Int
n_reqd_args | Extension -> DynFlags -> Bool
xopt Extension
LangExt.PostfixOperators DynFlags
dflags = Int
1
                         | Bool
otherwise                            = Int
2

       ; (HsWrapper
wrap_fn, (Scaled TcSigmaType
arg1_ty:[Scaled TcSigmaType]
arg_tys), TcSigmaType
op_res_ty)
           <- SDoc
-> CtOrigin
-> Maybe SDoc
-> Int
-> TcSigmaType
-> TcM (HsWrapper, [Scaled TcSigmaType], TcSigmaType)
matchActualFunTysRho (LHsExpr GhcRn -> SDoc
mk_op_msg LHsExpr GhcRn
op) CtOrigin
fn_orig
                                   (SDoc -> Maybe SDoc
forall a. a -> Maybe a
Just (GenLocated SrcSpan (HsExpr GhcRn) -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
op)) Int
n_reqd_args TcSigmaType
op_ty
       ; Located (HsExpr GhcTc)
arg1' <- HsExpr GhcRn
-> LHsExpr GhcRn
-> Scaled TcSigmaType
-> Int
-> TcM (LHsExpr GhcTc)
tcValArg (GenLocated SrcSpan (HsExpr GhcRn) -> HsExpr GhcRn
forall l e. GenLocated l e -> e
unLoc GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
op) LHsExpr GhcRn
arg1 Scaled TcSigmaType
arg1_ty Int
1
       ; let expr' :: HsExpr GhcTc
expr'      = XSectionL GhcTc -> LHsExpr GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XSectionL p -> LHsExpr p -> LHsExpr p -> HsExpr p
SectionL XSectionL GhcRn
XSectionL GhcTc
x Located (HsExpr GhcTc)
LHsExpr GhcTc
arg1' (HsWrapper -> LHsExpr GhcTc -> LHsExpr GhcTc
mkLHsWrap HsWrapper
wrap_fn Located (HsExpr GhcTc)
LHsExpr GhcTc
op')
             act_res_ty :: TcSigmaType
act_res_ty = [Scaled TcSigmaType] -> TcSigmaType -> TcSigmaType
mkVisFunTys [Scaled TcSigmaType]
arg_tys TcSigmaType
op_res_ty
       ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResultMono HsExpr GhcRn
expr HsExpr GhcTc
expr' TcSigmaType
act_res_ty ExpSigmaType
res_ty }
  where
    fn_orig :: CtOrigin
fn_orig = LHsExpr GhcRn -> CtOrigin
lexprCtOrigin LHsExpr GhcRn
op
    -- It's important to use the origin of 'op', so that call-stacks
    -- come out right; they are driven by the OccurrenceOf CtOrigin
    -- See #13285

tcExpr expr :: HsExpr GhcRn
expr@(ExplicitTuple XExplicitTuple GhcRn
x [LHsTupArg GhcRn]
tup_args Boxity
boxity) ExpSigmaType
res_ty
  | (Located (HsTupArg GhcRn) -> Bool)
-> [Located (HsTupArg GhcRn)] -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
all Located (HsTupArg GhcRn) -> Bool
forall (p :: Pass). LHsTupArg (GhcPass p) -> Bool
tupArgPresent [Located (HsTupArg GhcRn)]
[LHsTupArg GhcRn]
tup_args
  = do { let arity :: Int
arity  = [Located (HsTupArg GhcRn)] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [Located (HsTupArg GhcRn)]
[LHsTupArg GhcRn]
tup_args
             tup_tc :: TyCon
tup_tc = Boxity -> Int -> TyCon
tupleTyCon Boxity
boxity Int
arity
               -- NB: tupleTyCon doesn't flatten 1-tuples
               -- See Note [Don't flatten tuples from HsSyn] in GHC.Core.Make
       ; TcSigmaType
res_ty <- ExpSigmaType -> TcM TcSigmaType
expTypeToType ExpSigmaType
res_ty
       ; (TcCoercionR
coi, [TcSigmaType]
arg_tys) <- TyCon -> TcSigmaType -> TcM (TcCoercionR, [TcSigmaType])
matchExpectedTyConApp TyCon
tup_tc TcSigmaType
res_ty
                           -- Unboxed tuples have RuntimeRep vars, which we
                           -- don't care about here
                           -- See Note [Unboxed tuple RuntimeRep vars] in GHC.Core.TyCon
       ; let arg_tys' :: [TcSigmaType]
arg_tys' = case Boxity
boxity of Boxity
Unboxed -> Int -> [TcSigmaType] -> [TcSigmaType]
forall a. Int -> [a] -> [a]
drop Int
arity [TcSigmaType]
arg_tys
                                       Boxity
Boxed   -> [TcSigmaType]
arg_tys
       ; [Located (HsTupArg GhcTc)]
tup_args1 <- [LHsTupArg GhcRn] -> [TcSigmaType] -> TcM [LHsTupArg GhcTc]
tcTupArgs [LHsTupArg GhcRn]
tup_args [TcSigmaType]
arg_tys'
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ TcCoercionR -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrapCo TcCoercionR
coi (XExplicitTuple GhcTc -> [LHsTupArg GhcTc] -> Boxity -> HsExpr GhcTc
forall p. XExplicitTuple p -> [LHsTupArg p] -> Boxity -> HsExpr p
ExplicitTuple XExplicitTuple GhcRn
XExplicitTuple GhcTc
x [Located (HsTupArg GhcTc)]
[LHsTupArg GhcTc]
tup_args1 Boxity
boxity) }

  | Bool
otherwise
  = -- The tup_args are a mixture of Present and Missing (for tuple sections)
    do { let arity :: Int
arity = [Located (HsTupArg GhcRn)] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [Located (HsTupArg GhcRn)]
[LHsTupArg GhcRn]
tup_args

       ; [TcSigmaType]
arg_tys <- case Boxity
boxity of
           { Boxity
Boxed   -> Int -> TcSigmaType -> IOEnv (Env TcGblEnv TcLclEnv) [TcSigmaType]
newFlexiTyVarTys Int
arity TcSigmaType
liftedTypeKind
           ; Boxity
Unboxed -> Int
-> TcM TcSigmaType -> IOEnv (Env TcGblEnv TcLclEnv) [TcSigmaType]
forall (m :: * -> *) a. Applicative m => Int -> m a -> m [a]
replicateM Int
arity TcM TcSigmaType
newOpenFlexiTyVarTy }

       -- Handle tuple sections where
       ; [Located (HsTupArg GhcTc)]
tup_args1 <- [LHsTupArg GhcRn] -> [TcSigmaType] -> TcM [LHsTupArg GhcTc]
tcTupArgs [LHsTupArg GhcRn]
tup_args [TcSigmaType]
arg_tys

       ; let expr' :: HsExpr GhcTc
expr'       = XExplicitTuple GhcTc -> [LHsTupArg GhcTc] -> Boxity -> HsExpr GhcTc
forall p. XExplicitTuple p -> [LHsTupArg p] -> Boxity -> HsExpr p
ExplicitTuple XExplicitTuple GhcRn
XExplicitTuple GhcTc
x [Located (HsTupArg GhcTc)]
[LHsTupArg GhcTc]
tup_args1 Boxity
boxity
             missing_tys :: [Scaled TcSigmaType]
missing_tys = [TcSigmaType -> TcSigmaType -> Scaled TcSigmaType
forall a. TcSigmaType -> a -> Scaled a
Scaled TcSigmaType
mult TcSigmaType
ty | (L SrcSpan
_ (Missing (Scaled mult _)), TcSigmaType
ty) <- [Located (HsTupArg GhcTc)]
-> [TcSigmaType] -> [(Located (HsTupArg GhcTc), TcSigmaType)]
forall a b. [a] -> [b] -> [(a, b)]
zip [Located (HsTupArg GhcTc)]
tup_args1 [TcSigmaType]
arg_tys]

             -- See Note [Linear fields generalization] in GHC.Tc.Gen.App
             act_res_ty :: TcSigmaType
act_res_ty
                 = [Scaled TcSigmaType] -> TcSigmaType -> TcSigmaType
mkVisFunTys [Scaled TcSigmaType]
missing_tys (Boxity -> [TcSigmaType] -> TcSigmaType
mkTupleTy1 Boxity
boxity [TcSigmaType]
arg_tys)
                   -- See Note [Don't flatten tuples from HsSyn] in GHC.Core.Make

       ; String -> SDoc -> TcRn ()
traceTc String
"ExplicitTuple" (TcSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr TcSigmaType
act_res_ty SDoc -> SDoc -> SDoc
$$ ExpSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr ExpSigmaType
res_ty)

       ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResultMono HsExpr GhcRn
expr HsExpr GhcTc
expr' TcSigmaType
act_res_ty ExpSigmaType
res_ty }

tcExpr (ExplicitSum XExplicitSum GhcRn
_ Int
alt Int
arity LHsExpr GhcRn
expr) ExpSigmaType
res_ty
  = do { let sum_tc :: TyCon
sum_tc = Int -> TyCon
sumTyCon Int
arity
       ; TcSigmaType
res_ty <- ExpSigmaType -> TcM TcSigmaType
expTypeToType ExpSigmaType
res_ty
       ; (TcCoercionR
coi, [TcSigmaType]
arg_tys) <- TyCon -> TcSigmaType -> TcM (TcCoercionR, [TcSigmaType])
matchExpectedTyConApp TyCon
sum_tc TcSigmaType
res_ty
       ; -- Drop levity vars, we don't care about them here
         let arg_tys' :: [TcSigmaType]
arg_tys' = Int -> [TcSigmaType] -> [TcSigmaType]
forall a. Int -> [a] -> [a]
drop Int
arity [TcSigmaType]
arg_tys
       ; Located (HsExpr GhcTc)
expr' <- LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr ([TcSigmaType]
arg_tys' [TcSigmaType] -> Int -> TcSigmaType
forall a. Outputable a => [a] -> Int -> a
`getNth` (Int
alt Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
1))
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ TcCoercionR -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrapCo TcCoercionR
coi (XExplicitSum GhcTc -> Int -> Int -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XExplicitSum p -> Int -> Int -> LHsExpr p -> HsExpr p
ExplicitSum [TcSigmaType]
XExplicitSum GhcTc
arg_tys' Int
alt Int
arity Located (HsExpr GhcTc)
LHsExpr GhcTc
expr' ) }

-- This will see the empty list only when -XOverloadedLists.
-- See Note [Empty lists] in GHC.Hs.Expr.
tcExpr (ExplicitList XExplicitList GhcRn
_ Maybe (SyntaxExpr GhcRn)
witness [LHsExpr GhcRn]
exprs) ExpSigmaType
res_ty
  = case Maybe (SyntaxExpr GhcRn)
witness of
      Maybe (SyntaxExpr GhcRn)
Nothing   -> do  { TcSigmaType
res_ty <- ExpSigmaType -> TcM TcSigmaType
expTypeToType ExpSigmaType
res_ty
                       ; (TcCoercionR
coi, TcSigmaType
elt_ty) <- TcSigmaType -> TcM (TcCoercionR, TcSigmaType)
matchExpectedListTy TcSigmaType
res_ty
                       ; [Located (HsExpr GhcTc)]
exprs' <- (GenLocated SrcSpan (HsExpr GhcRn)
 -> TcRn (Located (HsExpr GhcTc)))
-> [GenLocated SrcSpan (HsExpr GhcRn)]
-> IOEnv (Env TcGblEnv TcLclEnv) [Located (HsExpr GhcTc)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (TcSigmaType
-> GenLocated SrcSpan (HsExpr GhcRn)
-> TcRn (Located (HsExpr GhcTc))
tc_elt TcSigmaType
elt_ty) [GenLocated SrcSpan (HsExpr GhcRn)]
[LHsExpr GhcRn]
exprs
                       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$
                         TcCoercionR -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrapCo TcCoercionR
coi (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$ XExplicitList GhcTc
-> Maybe (SyntaxExpr GhcTc) -> [LHsExpr GhcTc] -> HsExpr GhcTc
forall p.
XExplicitList p -> Maybe (SyntaxExpr p) -> [LHsExpr p] -> HsExpr p
ExplicitList TcSigmaType
XExplicitList GhcTc
elt_ty Maybe (SyntaxExpr GhcTc)
forall a. Maybe a
Nothing [Located (HsExpr GhcTc)]
[LHsExpr GhcTc]
exprs' }

      Just SyntaxExpr GhcRn
fln -> do { (([Located (HsExpr GhcTc)]
exprs', TcSigmaType
elt_ty), SyntaxExprTc
fln')
                         <- CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcM ([Located (HsExpr GhcTc)], TcSigmaType))
-> TcM (([Located (HsExpr GhcTc)], TcSigmaType), SyntaxExprTc)
forall a.
CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
tcSyntaxOp CtOrigin
ListOrigin SyntaxExprRn
SyntaxExpr GhcRn
fln
                                       [TcSigmaType -> SyntaxOpType
synKnownType TcSigmaType
intTy, SyntaxOpType
SynList] ExpSigmaType
res_ty (([TcSigmaType]
  -> [TcSigmaType] -> TcM ([Located (HsExpr GhcTc)], TcSigmaType))
 -> TcM (([Located (HsExpr GhcTc)], TcSigmaType), SyntaxExprTc))
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcM ([Located (HsExpr GhcTc)], TcSigmaType))
-> TcM (([Located (HsExpr GhcTc)], TcSigmaType), SyntaxExprTc)
forall a b. (a -> b) -> a -> b
$
                            \ [TcSigmaType
elt_ty] [TcSigmaType
_int_mul, TcSigmaType
list_mul] ->
                              -- We ignore _int_mul because the integer (first
                              -- argument of fromListN) is statically known: it
                              -- is desugared to a literal. Therefore there is
                              -- no variable of which to scale the usage in that
                              -- first argument, and `_int_mul` is completely
                              -- free in this expression.
                            do { [Located (HsExpr GhcTc)]
exprs' <-
                                    (GenLocated SrcSpan (HsExpr GhcRn)
 -> TcRn (Located (HsExpr GhcTc)))
-> [GenLocated SrcSpan (HsExpr GhcRn)]
-> IOEnv (Env TcGblEnv TcLclEnv) [Located (HsExpr GhcTc)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
list_mul (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> (GenLocated SrcSpan (HsExpr GhcRn)
    -> TcRn (Located (HsExpr GhcTc)))
-> GenLocated SrcSpan (HsExpr GhcRn)
-> TcRn (Located (HsExpr GhcTc))
forall b c a. (b -> c) -> (a -> b) -> a -> c
. TcSigmaType
-> GenLocated SrcSpan (HsExpr GhcRn)
-> TcRn (Located (HsExpr GhcTc))
tc_elt TcSigmaType
elt_ty) [GenLocated SrcSpan (HsExpr GhcRn)]
[LHsExpr GhcRn]
exprs
                               ; ([Located (HsExpr GhcTc)], TcSigmaType)
-> TcM ([Located (HsExpr GhcTc)], TcSigmaType)
forall (m :: * -> *) a. Monad m => a -> m a
return ([Located (HsExpr GhcTc)]
exprs', TcSigmaType
elt_ty) }

                     ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ XExplicitList GhcTc
-> Maybe (SyntaxExpr GhcTc) -> [LHsExpr GhcTc] -> HsExpr GhcTc
forall p.
XExplicitList p -> Maybe (SyntaxExpr p) -> [LHsExpr p] -> HsExpr p
ExplicitList TcSigmaType
XExplicitList GhcTc
elt_ty (SyntaxExprTc -> Maybe SyntaxExprTc
forall a. a -> Maybe a
Just SyntaxExprTc
fln') [Located (HsExpr GhcTc)]
[LHsExpr GhcTc]
exprs' }
     where tc_elt :: TcSigmaType
-> GenLocated SrcSpan (HsExpr GhcRn) -> TcM (LHsExpr GhcTc)
tc_elt TcSigmaType
elt_ty GenLocated SrcSpan (HsExpr GhcRn)
expr = LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
expr TcSigmaType
elt_ty

{-
************************************************************************
*                                                                      *
                Let, case, if, do
*                                                                      *
************************************************************************
-}

tcExpr (HsLet XLet GhcRn
x (L l binds) LHsExpr GhcRn
expr) ExpSigmaType
res_ty
  = do  { (HsLocalBinds GhcTc
binds', Located (HsExpr GhcTc)
expr') <- HsLocalBinds GhcRn
-> TcRn (Located (HsExpr GhcTc))
-> TcM (HsLocalBinds GhcTc, Located (HsExpr GhcTc))
forall thing.
HsLocalBinds GhcRn -> TcM thing -> TcM (HsLocalBinds GhcTc, thing)
tcLocalBinds HsLocalBinds GhcRn
binds (TcRn (Located (HsExpr GhcTc))
 -> TcM (HsLocalBinds GhcTc, Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc))
-> TcM (HsLocalBinds GhcTc, Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$
                             LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExpr LHsExpr GhcRn
expr ExpSigmaType
res_ty
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XLet GhcTc -> LHsLocalBinds GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XLet p -> LHsLocalBinds p -> LHsExpr p -> HsExpr p
HsLet XLet GhcRn
XLet GhcTc
x (SrcSpan
-> HsLocalBinds GhcTc -> GenLocated SrcSpan (HsLocalBinds GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
l HsLocalBinds GhcTc
binds') Located (HsExpr GhcTc)
LHsExpr GhcTc
expr') }

tcExpr (HsCase XCase GhcRn
x LHsExpr GhcRn
scrut MatchGroup GhcRn (LHsExpr GhcRn)
matches) ExpSigmaType
res_ty
  = do  {  -- We used to typecheck the case alternatives first.
           -- The case patterns tend to give good type info to use
           -- when typechecking the scrutinee.  For example
           --   case (map f) of
           --     (x:xs) -> ...
           -- will report that map is applied to too few arguments
           --
           -- But now, in the GADT world, we need to typecheck the scrutinee
           -- first, to get type info that may be refined in the case alternatives
          let mult :: TcSigmaType
mult = TcSigmaType
Many
            -- There is not yet syntax or inference mechanism for case
            -- expressions to be anything else than unrestricted.

          -- Typecheck the scrutinee.  We use tcInferRho but tcInferSigma
          -- would also be possible (tcMatchesCase accepts sigma-types)
          -- Interesting litmus test: do these two behave the same?
          --     case id        of {..}
          --     case (\v -> v) of {..}
          -- This design choice is discussed in #17790
        ; (Located (HsExpr GhcTc)
scrut', TcSigmaType
scrut_ty) <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
mult (TcRn (Located (HsExpr GhcTc), TcSigmaType)
 -> TcRn (Located (HsExpr GhcTc), TcSigmaType))
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRho LHsExpr GhcRn
scrut

        ; String -> SDoc -> TcRn ()
traceTc String
"HsCase" (TcSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr TcSigmaType
scrut_ty)
        ; MatchGroup GhcTc (Located (HsExpr GhcTc))
matches' <- TcMatchCtxt HsExpr
-> Scaled TcSigmaType
-> MatchGroup GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
-> ExpSigmaType
-> TcM (MatchGroup GhcTc (Located (HsExpr GhcTc)))
forall (body :: * -> *).
Outputable (body GhcRn) =>
TcMatchCtxt body
-> Scaled TcSigmaType
-> MatchGroup GhcRn (Located (body GhcRn))
-> ExpSigmaType
-> TcM (MatchGroup GhcTc (Located (body GhcTc)))
tcMatchesCase TcMatchCtxt HsExpr
match_ctxt (TcSigmaType -> TcSigmaType -> Scaled TcSigmaType
forall a. TcSigmaType -> a -> Scaled a
Scaled TcSigmaType
mult TcSigmaType
scrut_ty) MatchGroup GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
MatchGroup GhcRn (LHsExpr GhcRn)
matches ExpSigmaType
res_ty
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XCase GhcTc
-> LHsExpr GhcTc
-> MatchGroup GhcTc (LHsExpr GhcTc)
-> HsExpr GhcTc
forall p.
XCase p -> LHsExpr p -> MatchGroup p (LHsExpr p) -> HsExpr p
HsCase XCase GhcRn
XCase GhcTc
x Located (HsExpr GhcTc)
LHsExpr GhcTc
scrut' MatchGroup GhcTc (Located (HsExpr GhcTc))
MatchGroup GhcTc (LHsExpr GhcTc)
matches') }
 where
    match_ctxt :: TcMatchCtxt HsExpr
match_ctxt = MC :: forall (body :: * -> *).
HsMatchContext GhcRn
-> (Located (body GhcRn)
    -> ExpSigmaType -> TcM (Located (body GhcTc)))
-> TcMatchCtxt body
MC { mc_what :: HsMatchContext GhcRn
mc_what = HsMatchContext GhcRn
forall p. HsMatchContext p
CaseAlt,
                      mc_body :: GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
mc_body = GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcBody }

tcExpr (HsIf XIf GhcRn
x LHsExpr GhcRn
pred LHsExpr GhcRn
b1 LHsExpr GhcRn
b2) ExpSigmaType
res_ty
  = do { Located (HsExpr GhcTc)
pred'    <- LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckMonoExpr LHsExpr GhcRn
pred TcSigmaType
boolTy
       ; (UsageEnv
u1,Located (HsExpr GhcTc)
b1') <- TcRn (Located (HsExpr GhcTc))
-> TcM (UsageEnv, Located (HsExpr GhcTc))
forall a. TcM a -> TcM (UsageEnv, a)
tcCollectingUsage (TcRn (Located (HsExpr GhcTc))
 -> TcM (UsageEnv, Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc))
-> TcM (UsageEnv, Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExpr LHsExpr GhcRn
b1 ExpSigmaType
res_ty
       ; (UsageEnv
u2,Located (HsExpr GhcTc)
b2') <- TcRn (Located (HsExpr GhcTc))
-> TcM (UsageEnv, Located (HsExpr GhcTc))
forall a. TcM a -> TcM (UsageEnv, a)
tcCollectingUsage (TcRn (Located (HsExpr GhcTc))
 -> TcM (UsageEnv, Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc))
-> TcM (UsageEnv, Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcMonoExpr LHsExpr GhcRn
b2 ExpSigmaType
res_ty
       ; UsageEnv -> TcRn ()
tcEmitBindingUsage (UsageEnv -> UsageEnv -> UsageEnv
supUE UsageEnv
u1 UsageEnv
u2)
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XIf GhcTc
-> LHsExpr GhcTc -> LHsExpr GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XIf p -> LHsExpr p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsIf XIf GhcRn
XIf GhcTc
x Located (HsExpr GhcTc)
LHsExpr GhcTc
pred' Located (HsExpr GhcTc)
LHsExpr GhcTc
b1' Located (HsExpr GhcTc)
LHsExpr GhcTc
b2') }

tcExpr (HsMultiIf XMultiIf GhcRn
_ [LGRHS GhcRn (LHsExpr GhcRn)]
alts) ExpSigmaType
res_ty
  = do { [Located (GRHS GhcTc (Located (HsExpr GhcTc)))]
alts' <- (Located (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (Located (GRHS GhcTc (Located (HsExpr GhcTc)))))
-> [Located (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn)))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Located (GRHS GhcTc (Located (HsExpr GhcTc)))]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM ((GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
 -> TcM (GRHS GhcTc (Located (HsExpr GhcTc))))
-> Located (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Located (GRHS GhcTc (Located (HsExpr GhcTc))))
forall a b. (a -> TcM b) -> Located a -> TcM (Located b)
wrapLocM ((GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
  -> TcM (GRHS GhcTc (Located (HsExpr GhcTc))))
 -> Located (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (Located (GRHS GhcTc (Located (HsExpr GhcTc)))))
-> (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
    -> TcM (GRHS GhcTc (Located (HsExpr GhcTc))))
-> Located (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Located (GRHS GhcTc (Located (HsExpr GhcTc))))
forall a b. (a -> b) -> a -> b
$ TcMatchCtxt HsExpr
-> ExpSigmaType
-> GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
-> TcM (GRHS GhcTc (Located (HsExpr GhcTc)))
forall (body :: * -> *).
TcMatchCtxt body
-> ExpSigmaType
-> GRHS GhcRn (Located (body GhcRn))
-> TcM (GRHS GhcTc (Located (body GhcTc)))
tcGRHS TcMatchCtxt HsExpr
match_ctxt ExpSigmaType
res_ty) [Located (GRHS GhcRn (GenLocated SrcSpan (HsExpr GhcRn)))]
[LGRHS GhcRn (LHsExpr GhcRn)]
alts
       ; TcSigmaType
res_ty <- ExpSigmaType -> TcM TcSigmaType
readExpType ExpSigmaType
res_ty
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (XMultiIf GhcTc -> [LGRHS GhcTc (LHsExpr GhcTc)] -> HsExpr GhcTc
forall p. XMultiIf p -> [LGRHS p (LHsExpr p)] -> HsExpr p
HsMultiIf TcSigmaType
XMultiIf GhcTc
res_ty [Located (GRHS GhcTc (Located (HsExpr GhcTc)))]
[LGRHS GhcTc (LHsExpr GhcTc)]
alts') }
  where match_ctxt :: TcMatchCtxt HsExpr
match_ctxt = MC :: forall (body :: * -> *).
HsMatchContext GhcRn
-> (Located (body GhcRn)
    -> ExpSigmaType -> TcM (Located (body GhcTc)))
-> TcMatchCtxt body
MC { mc_what :: HsMatchContext GhcRn
mc_what = HsMatchContext GhcRn
forall p. HsMatchContext p
IfAlt, mc_body :: GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
mc_body = GenLocated SrcSpan (HsExpr GhcRn)
-> ExpSigmaType -> TcRn (Located (HsExpr GhcTc))
LHsExpr GhcRn -> ExpSigmaType -> TcM (LHsExpr GhcTc)
tcBody }

tcExpr (HsDo XDo GhcRn
_ HsStmtContext GhcRn
do_or_lc XRec GhcRn [ExprLStmt GhcRn]
stmts) ExpSigmaType
res_ty
  = HsStmtContext GhcRn
-> Located [ExprLStmt GhcRn] -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcDoStmts HsStmtContext GhcRn
do_or_lc Located [ExprLStmt GhcRn]
XRec GhcRn [ExprLStmt GhcRn]
stmts ExpSigmaType
res_ty

tcExpr (HsProc XProc GhcRn
x LPat GhcRn
pat LHsCmdTop GhcRn
cmd) ExpSigmaType
res_ty
  = do  { (Located (Pat GhcTc)
pat', Located (HsCmdTop GhcTc)
cmd', TcCoercionR
coi) <- LPat GhcRn
-> LHsCmdTop GhcRn
-> ExpSigmaType
-> TcM (LPat GhcTc, LHsCmdTop GhcTc, TcCoercionR)
tcProc LPat GhcRn
pat LHsCmdTop GhcRn
cmd ExpSigmaType
res_ty
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ TcCoercionR -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrapCo TcCoercionR
coi (XProc GhcTc -> LPat GhcTc -> LHsCmdTop GhcTc -> HsExpr GhcTc
forall p. XProc p -> LPat p -> LHsCmdTop p -> HsExpr p
HsProc XProc GhcRn
XProc GhcTc
x Located (Pat GhcTc)
LPat GhcTc
pat' Located (HsCmdTop GhcTc)
LHsCmdTop GhcTc
cmd') }

-- Typechecks the static form and wraps it with a call to 'fromStaticPtr'.
-- See Note [Grand plan for static forms] in GHC.Iface.Tidy.StaticPtrTable for an overview.
-- To type check
--      (static e) :: p a
-- we want to check (e :: a),
-- and wrap (static e) in a call to
--    fromStaticPtr :: IsStatic p => StaticPtr a -> p a

tcExpr (HsStatic XStatic GhcRn
fvs LHsExpr GhcRn
expr) ExpSigmaType
res_ty
  = do  { TcSigmaType
res_ty          <- ExpSigmaType -> TcM TcSigmaType
expTypeToType ExpSigmaType
res_ty
        ; (TcCoercionR
co, (TcSigmaType
p_ty, TcSigmaType
expr_ty)) <- TcSigmaType -> TcM (TcCoercionR, (TcSigmaType, TcSigmaType))
matchExpectedAppTy TcSigmaType
res_ty
        ; (Located (HsExpr GhcTc)
expr', WantedConstraints
lie)    <- TcRn (Located (HsExpr GhcTc))
-> TcM (Located (HsExpr GhcTc), WantedConstraints)
forall a. TcM a -> TcM (a, WantedConstraints)
captureConstraints (TcRn (Located (HsExpr GhcTc))
 -> TcM (Located (HsExpr GhcTc), WantedConstraints))
-> TcRn (Located (HsExpr GhcTc))
-> TcM (Located (HsExpr GhcTc), WantedConstraints)
forall a b. (a -> b) -> a -> b
$
            SDoc
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. SDoc -> TcM a -> TcM a
addErrCtxt (SDoc -> Int -> SDoc -> SDoc
hang (String -> SDoc
text String
"In the body of a static form:")
                             Int
2 (GenLocated SrcSpan (HsExpr GhcRn) -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
expr)
                       ) (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$
            LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExprNC LHsExpr GhcRn
expr TcSigmaType
expr_ty

        -- Check that the free variables of the static form are closed.
        -- It's OK to use nonDetEltsUniqSet here as the only side effects of
        -- checkClosedInStaticForm are error messages.
        ; (Name -> TcRn ()) -> [Name] -> TcRn ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
(a -> m b) -> t a -> m ()
mapM_ Name -> TcRn ()
checkClosedInStaticForm ([Name] -> TcRn ()) -> [Name] -> TcRn ()
forall a b. (a -> b) -> a -> b
$ UniqSet Name -> [Name]
forall elt. UniqSet elt -> [elt]
nonDetEltsUniqSet UniqSet Name
XStatic GhcRn
fvs

        -- Require the type of the argument to be Typeable.
        -- The evidence is not used, but asking the constraint ensures that
        -- the current implementation is as restrictive as future versions
        -- of the StaticPointers extension.
        ; Class
typeableClass <- Name -> TcM Class
tcLookupClass Name
typeableClassName
        ; Id
_ <- CtOrigin -> TcSigmaType -> TcM Id
emitWantedEvVar CtOrigin
StaticOrigin (TcSigmaType -> TcM Id) -> TcSigmaType -> TcM Id
forall a b. (a -> b) -> a -> b
$
                  TyCon -> [TcSigmaType] -> TcSigmaType
mkTyConApp (Class -> TyCon
classTyCon Class
typeableClass)
                             [TcSigmaType
liftedTypeKind, TcSigmaType
expr_ty]

        -- Insert the constraints of the static form in a global list for later
        -- validation.
        ; WantedConstraints -> TcRn ()
emitStaticConstraints WantedConstraints
lie

        -- Wrap the static form with the 'fromStaticPtr' call.
        ; HsExpr GhcTc
fromStaticPtr <- CtOrigin -> Name -> [TcSigmaType] -> TcM (HsExpr GhcTc)
newMethodFromName CtOrigin
StaticOrigin Name
fromStaticPtrName
                                             [TcSigmaType
p_ty]
        ; let wrap :: HsWrapper
wrap = [TcSigmaType] -> HsWrapper
mkWpTyApps [TcSigmaType
expr_ty]
        ; SrcSpan
loc <- TcRn SrcSpan
getSrcSpanM
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ TcCoercionR -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrapCo TcCoercionR
co (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$ XApp GhcTc -> LHsExpr GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XApp p -> LHsExpr p -> LHsExpr p -> HsExpr p
HsApp NoExtField
XApp GhcTc
noExtField
                                         (SrcSpan -> HsExpr GhcTc -> Located (HsExpr GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (HsExpr GhcTc -> Located (HsExpr GhcTc))
-> HsExpr GhcTc -> Located (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap HsExpr GhcTc
fromStaticPtr)
                                         (SrcSpan -> HsExpr GhcTc -> Located (HsExpr GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XStatic GhcTc -> LHsExpr GhcTc -> HsExpr GhcTc
forall p. XStatic p -> LHsExpr p -> HsExpr p
HsStatic XStatic GhcRn
XStatic GhcTc
fvs Located (HsExpr GhcTc)
LHsExpr GhcTc
expr'))
        }

{-
************************************************************************
*                                                                      *
                Record construction and update
*                                                                      *
************************************************************************
-}

tcExpr expr :: HsExpr GhcRn
expr@(RecordCon { rcon_con_name :: forall p. HsExpr p -> LIdP p
rcon_con_name = L loc con_name
                       , rcon_flds :: forall p. HsExpr p -> HsRecordBinds p
rcon_flds = HsRecordBinds GhcRn
rbinds }) ExpSigmaType
res_ty
  = do  { ConLike
con_like <- Name -> TcM ConLike
tcLookupConLike Name
con_name

        -- Check for missing fields
        ; ConLike -> HsRecordBinds GhcRn -> TcRn ()
checkMissingFields ConLike
con_like HsRecordBinds GhcRn
rbinds

        ; (HsExpr GhcTc
con_expr, TcSigmaType
con_sigma) <- Name -> TcM (HsExpr GhcTc, TcSigmaType)
tcInferId Name
con_name
        ; (HsWrapper
con_wrap, TcSigmaType
con_tau)   <- CtOrigin -> TcSigmaType -> TcM (HsWrapper, TcSigmaType)
topInstantiate CtOrigin
orig TcSigmaType
con_sigma
              -- a shallow instantiation should really be enough for
              -- a data constructor.
        ; let arity :: Int
arity = ConLike -> Int
conLikeArity ConLike
con_like
              Right ([Scaled TcSigmaType]
arg_tys, TcSigmaType
actual_res_ty) = Int
-> TcSigmaType -> Either Int ([Scaled TcSigmaType], TcSigmaType)
tcSplitFunTysN Int
arity TcSigmaType
con_tau
        ; case ConLike -> Maybe Id
conLikeWrapId_maybe ConLike
con_like of {
               Maybe Id
Nothing -> Name -> TcM (HsExpr GhcTc)
forall name a. Outputable name => name -> TcM a
nonBidirectionalErr (ConLike -> Name
conLikeName ConLike
con_like) ;
               Just Id
con_id ->

     do { HsRecFields GhcTc (Located (HsExpr GhcTc))
rbinds' <- ConLike
-> [TcSigmaType]
-> HsRecordBinds GhcRn
-> TcM (HsRecordBinds GhcTc)
tcRecordBinds ConLike
con_like ((Scaled TcSigmaType -> TcSigmaType)
-> [Scaled TcSigmaType] -> [TcSigmaType]
forall a b. (a -> b) -> [a] -> [b]
map Scaled TcSigmaType -> TcSigmaType
forall a. Scaled a -> a
scaledThing [Scaled TcSigmaType]
arg_tys) HsRecordBinds GhcRn
rbinds
                   -- It is currently not possible for a record to have
                   -- multiplicities. When they do, `tcRecordBinds` will take
                   -- scaled types instead. Meanwhile, it's safe to take
                   -- `scaledThing` above, as we know all the multiplicities are
                   -- Many.
        ; let rcon_tc :: RecordConTc
rcon_tc = RecordConTc :: ConLike -> HsExpr GhcTc -> RecordConTc
RecordConTc
                           { rcon_con_like :: ConLike
rcon_con_like = ConLike
con_like
                           , rcon_con_expr :: HsExpr GhcTc
rcon_con_expr = HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
con_wrap HsExpr GhcTc
con_expr }
              expr' :: HsExpr GhcTc
expr' = RecordCon :: forall p. XRecordCon p -> LIdP p -> HsRecordBinds p -> HsExpr p
RecordCon { rcon_ext :: XRecordCon GhcTc
rcon_ext = RecordConTc
XRecordCon GhcTc
rcon_tc
                                , rcon_con_name :: LIdP GhcTc
rcon_con_name = SrcSpan -> Id -> Located Id
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc Id
con_id
                                , rcon_flds :: HsRecordBinds GhcTc
rcon_flds = HsRecFields GhcTc (Located (HsExpr GhcTc))
HsRecordBinds GhcTc
rbinds' }

        ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResultMono HsExpr GhcRn
expr HsExpr GhcTc
expr' TcSigmaType
actual_res_ty ExpSigmaType
res_ty } } }
  where
    orig :: CtOrigin
orig = Name -> CtOrigin
OccurrenceOf Name
con_name

{-
Note [Type of a record update]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The main complication with RecordUpd is that we need to explicitly
handle the *non-updated* fields.  Consider:

        data T a b c = MkT1 { fa :: a, fb :: (b,c) }
                     | MkT2 { fa :: a, fb :: (b,c), fc :: c -> c }
                     | MkT3 { fd :: a }

        upd :: T a b c -> (b',c) -> T a b' c
        upd t x = t { fb = x}

The result type should be (T a b' c)
not (T a b c),   because 'b' *is not* mentioned in a non-updated field
not (T a b' c'), because 'c' *is*     mentioned in a non-updated field
NB that it's not good enough to look at just one constructor; we must
look at them all; cf #3219

After all, upd should be equivalent to:
        upd t x = case t of
                        MkT1 p q -> MkT1 p x
                        MkT2 a b -> MkT2 p b
                        MkT3 d   -> error ...

So we need to give a completely fresh type to the result record,
and then constrain it by the fields that are *not* updated ("p" above).
We call these the "fixed" type variables, and compute them in getFixedTyVars.

Note that because MkT3 doesn't contain all the fields being updated,
its RHS is simply an error, so it doesn't impose any type constraints.
Hence the use of 'relevant_cont'.

Note [Implicit type sharing]
~~~~~~~~~~~~~~~~~~~~~~~~~~~
We also take into account any "implicit" non-update fields.  For example
        data T a b where { MkT { f::a } :: T a a; ... }
So the "real" type of MkT is: forall ab. (a~b) => a -> T a b

Then consider
        upd t x = t { f=x }
We infer the type
        upd :: T a b -> a -> T a b
        upd (t::T a b) (x::a)
           = case t of { MkT (co:a~b) (_:a) -> MkT co x }
We can't give it the more general type
        upd :: T a b -> c -> T c b

Note [Criteria for update]
~~~~~~~~~~~~~~~~~~~~~~~~~~
We want to allow update for existentials etc, provided the updated
field isn't part of the existential. For example, this should be ok.
  data T a where { MkT { f1::a, f2::b->b } :: T a }
  f :: T a -> b -> T b
  f t b = t { f1=b }

The criterion we use is this:

  The types of the updated fields
  mention only the universally-quantified type variables
  of the data constructor

NB: this is not (quite) the same as being a "naughty" record selector
(See Note [Naughty record selectors]) in GHC.Tc.TyCl), at least
in the case of GADTs. Consider
   data T a where { MkT :: { f :: a } :: T [a] }
Then f is not "naughty" because it has a well-typed record selector.
But we don't allow updates for 'f'.  (One could consider trying to
allow this, but it makes my head hurt.  Badly.  And no one has asked
for it.)

In principle one could go further, and allow
  g :: T a -> T a
  g t = t { f2 = \x -> x }
because the expression is polymorphic...but that seems a bridge too far.

Note [Data family example]
~~~~~~~~~~~~~~~~~~~~~~~~~~
    data instance T (a,b) = MkT { x::a, y::b }
  --->
    data :TP a b = MkT { a::a, y::b }
    coTP a b :: T (a,b) ~ :TP a b

Suppose r :: T (t1,t2), e :: t3
Then  r { x=e } :: T (t3,t1)
  --->
      case r |> co1 of
        MkT x y -> MkT e y |> co2
      where co1 :: T (t1,t2) ~ :TP t1 t2
            co2 :: :TP t3 t2 ~ T (t3,t2)
The wrapping with co2 is done by the constructor wrapper for MkT

Outgoing invariants
~~~~~~~~~~~~~~~~~~~
In the outgoing (HsRecordUpd scrut binds cons in_inst_tys out_inst_tys):

  * cons are the data constructors to be updated

  * in_inst_tys, out_inst_tys have same length, and instantiate the
        *representation* tycon of the data cons.  In Note [Data
        family example], in_inst_tys = [t1,t2], out_inst_tys = [t3,t2]

Note [Mixed Record Field Updates]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Consider the following pattern synonym.

  data MyRec = MyRec { foo :: Int, qux :: String }

  pattern HisRec{f1, f2} = MyRec{foo = f1, qux=f2}

This allows updates such as the following

  updater :: MyRec -> MyRec
  updater a = a {f1 = 1 }

It would also make sense to allow the following update (which we reject).

  updater a = a {f1 = 1, qux = "two" } ==? MyRec 1 "two"

This leads to confusing behaviour when the selectors in fact refer the same
field.

  updater a = a {f1 = 1, foo = 2} ==? ???

For this reason, we reject a mixture of pattern synonym and normal record
selectors in the same update block. Although of course we still allow the
following.

  updater a = (a {f1 = 1}) {foo = 2}

  > updater (MyRec 0 "str")
  MyRec 2 "str"

-}

tcExpr expr :: HsExpr GhcRn
expr@(RecordUpd { rupd_expr :: forall p. HsExpr p -> LHsExpr p
rupd_expr = LHsExpr GhcRn
record_expr, rupd_flds :: forall p. HsExpr p -> [LHsRecUpdField p]
rupd_flds = [LHsRecUpdField GhcRn]
rbnds }) ExpSigmaType
res_ty
  = ASSERT( notNull rbnds )
    do  { -- STEP -2: typecheck the record_expr, the record to be updated
          (Located (HsExpr GhcTc)
record_expr', TcSigmaType
record_rho) <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
Many (TcRn (Located (HsExpr GhcTc), TcSigmaType)
 -> TcRn (Located (HsExpr GhcTc), TcSigmaType))
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
-> TcRn (Located (HsExpr GhcTc), TcSigmaType)
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcM (LHsExpr GhcTc, TcSigmaType)
tcInferRho LHsExpr GhcRn
record_expr
            -- Record update drops some of the content of the record (namely the
            -- content of the field being updated). As a consequence, unless the
            -- field being updated is unrestricted in the record, or we need an
            -- unrestricted record. Currently, we simply always require an
            -- unrestricted record.
            --
            -- Consider the following example:
            --
            -- data R a = R { self :: a }
            -- bad :: a ⊸ ()
            -- bad x = let r = R x in case r { self = () } of { R x' -> x' }
            --
            -- This should definitely *not* typecheck.

        -- STEP -1  See Note [Disambiguating record fields] in GHC.Tc.Gen.Head
        -- After this we know that rbinds is unambiguous
        ; [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
rbinds <- LHsExpr GhcRn
-> TcSigmaType
-> [LHsRecUpdField GhcRn]
-> ExpSigmaType
-> TcM [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
disambiguateRecordBinds LHsExpr GhcRn
record_expr TcSigmaType
record_rho [LHsRecUpdField GhcRn]
rbnds ExpSigmaType
res_ty
        ; let upd_flds :: [AmbiguousFieldOcc GhcTc]
upd_flds = (GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> AmbiguousFieldOcc GhcTc)
-> [GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> [AmbiguousFieldOcc GhcTc]
forall a b. (a -> b) -> [a] -> [b]
map (GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
-> AmbiguousFieldOcc GhcTc
forall l e. GenLocated l e -> e
unLoc (GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
 -> AmbiguousFieldOcc GhcTc)
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc))
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> AmbiguousFieldOcc GhcTc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. HsRecField'
  (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl (HsRecField'
   (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
 -> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc))
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc) [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
rbinds
              upd_fld_occs :: [FastString]
upd_fld_occs = (AmbiguousFieldOcc GhcTc -> FastString)
-> [AmbiguousFieldOcc GhcTc] -> [FastString]
forall a b. (a -> b) -> [a] -> [b]
map (OccName -> FastString
occNameFS (OccName -> FastString)
-> (AmbiguousFieldOcc GhcTc -> OccName)
-> AmbiguousFieldOcc GhcTc
-> FastString
forall b c a. (b -> c) -> (a -> b) -> a -> c
. RdrName -> OccName
rdrNameOcc (RdrName -> OccName)
-> (AmbiguousFieldOcc GhcTc -> RdrName)
-> AmbiguousFieldOcc GhcTc
-> OccName
forall b c a. (b -> c) -> (a -> b) -> a -> c
. AmbiguousFieldOcc GhcTc -> RdrName
forall (p :: Pass). AmbiguousFieldOcc (GhcPass p) -> RdrName
rdrNameAmbiguousFieldOcc) [AmbiguousFieldOcc GhcTc]
upd_flds
              sel_ids :: [Id]
sel_ids      = (AmbiguousFieldOcc GhcTc -> Id)
-> [AmbiguousFieldOcc GhcTc] -> [Id]
forall a b. (a -> b) -> [a] -> [b]
map AmbiguousFieldOcc GhcTc -> Id
selectorAmbiguousFieldOcc [AmbiguousFieldOcc GhcTc]
upd_flds
        -- STEP 0
        -- Check that the field names are really field names
        -- and they are all field names for proper records or
        -- all field names for pattern synonyms.
        ; let bad_guys :: [TcRn ()]
bad_guys = [ SrcSpan -> TcRn () -> TcRn ()
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
loc (TcRn () -> TcRn ()) -> TcRn () -> TcRn ()
forall a b. (a -> b) -> a -> b
$ SDoc -> TcRn ()
addErrTc (Name -> SDoc
notSelector Name
fld_name)
                         | GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
fld <- [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
rbinds,
                           -- Excludes class ops
                           let L SrcSpan
loc Id
sel_id = HsRecField'
  (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
-> Located Id
forall arg. HsRecField' (AmbiguousFieldOcc GhcTc) arg -> Located Id
hsRecUpdFieldId (GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
fld),
                           Bool -> Bool
not (Id -> Bool
isRecordSelector Id
sel_id),
                           let fld_name :: Name
fld_name = Id -> Name
idName Id
sel_id ]
        ; Bool -> TcRn () -> TcRn ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless ([TcRn ()] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [TcRn ()]
bad_guys) ([TcRn ()] -> IOEnv (Env TcGblEnv TcLclEnv) [()]
forall (t :: * -> *) (m :: * -> *) a.
(Traversable t, Monad m) =>
t (m a) -> m (t a)
sequence [TcRn ()]
bad_guys IOEnv (Env TcGblEnv TcLclEnv) [()] -> TcRn () -> TcRn ()
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> TcRn ()
forall env a. IOEnv env a
failM)
        -- See note [Mixed Record Selectors]
        ; let ([Id]
data_sels, [Id]
pat_syn_sels) =
                (Id -> Bool) -> [Id] -> ([Id], [Id])
forall a. (a -> Bool) -> [a] -> ([a], [a])
partition Id -> Bool
isDataConRecordSelector [Id]
sel_ids
        ; MASSERT( all isPatSynRecordSelector pat_syn_sels )
        ; Bool -> SDoc -> TcRn ()
checkTc ( [Id] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Id]
data_sels Bool -> Bool -> Bool
|| [Id] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Id]
pat_syn_sels )
                  ( [Id] -> [Id] -> SDoc
mixedSelectors [Id]
data_sels [Id]
pat_syn_sels )

        -- STEP 1
        -- Figure out the tycon and data cons from the first field name
        ; let   -- It's OK to use the non-tc splitters here (for a selector)
              Id
sel_id : [Id]
_  = [Id]
sel_ids

              mtycon :: Maybe TyCon
              mtycon :: Maybe TyCon
mtycon = case Id -> IdDetails
idDetails Id
sel_id of
                          RecSelId (RecSelData TyCon
tycon) Bool
_ -> TyCon -> Maybe TyCon
forall a. a -> Maybe a
Just TyCon
tycon
                          IdDetails
_ -> Maybe TyCon
forall a. Maybe a
Nothing

              con_likes :: [ConLike]
              con_likes :: [ConLike]
con_likes = case Id -> IdDetails
idDetails Id
sel_id of
                             RecSelId (RecSelData TyCon
tc) Bool
_
                                -> (DataCon -> ConLike) -> [DataCon] -> [ConLike]
forall a b. (a -> b) -> [a] -> [b]
map DataCon -> ConLike
RealDataCon (TyCon -> [DataCon]
tyConDataCons TyCon
tc)
                             RecSelId (RecSelPatSyn PatSyn
ps) Bool
_
                                -> [PatSyn -> ConLike
PatSynCon PatSyn
ps]
                             IdDetails
_  -> String -> [ConLike]
forall a. String -> a
panic String
"tcRecordUpd"
                -- NB: for a data type family, the tycon is the instance tycon

              relevant_cons :: [ConLike]
relevant_cons = [ConLike] -> [FastString] -> [ConLike]
conLikesWithFields [ConLike]
con_likes [FastString]
upd_fld_occs
                -- A constructor is only relevant to this process if
                -- it contains *all* the fields that are being updated
                -- Other ones will cause a runtime error if they occur

        -- Step 2
        -- Check that at least one constructor has all the named fields
        -- i.e. has an empty set of bad fields returned by badFields
        ; Bool -> SDoc -> TcRn ()
checkTc (Bool -> Bool
not ([ConLike] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [ConLike]
relevant_cons)) ([LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
-> [ConLike] -> SDoc
badFieldsUpd [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
rbinds [ConLike]
con_likes)

        -- Take apart a representative constructor
        ; let con1 :: ConLike
con1 = ASSERT( not (null relevant_cons) ) head relevant_cons
              ([Id]
con1_tvs, [Id]
_, [EqSpec]
_, [TcSigmaType]
_prov_theta, [TcSigmaType]
req_theta, [Scaled TcSigmaType]
scaled_con1_arg_tys, TcSigmaType
_)
                 = ConLike
-> ([Id], [Id], [EqSpec], [TcSigmaType], [TcSigmaType],
    [Scaled TcSigmaType], TcSigmaType)
conLikeFullSig ConLike
con1
              con1_arg_tys :: [TcSigmaType]
con1_arg_tys = (Scaled TcSigmaType -> TcSigmaType)
-> [Scaled TcSigmaType] -> [TcSigmaType]
forall a b. (a -> b) -> [a] -> [b]
map Scaled TcSigmaType -> TcSigmaType
forall a. Scaled a -> a
scaledThing [Scaled TcSigmaType]
scaled_con1_arg_tys
                -- We can safely drop the fields' multiplicities because
                -- they are currently always 1: there is no syntax for record
                -- fields with other multiplicities yet. This way we don't need
                -- to handle it in the rest of the function
              con1_flds :: [FastString]
con1_flds   = (FieldLbl Name -> FastString) -> [FieldLbl Name] -> [FastString]
forall a b. (a -> b) -> [a] -> [b]
map FieldLbl Name -> FastString
forall a. FieldLbl a -> FastString
flLabel ([FieldLbl Name] -> [FastString])
-> [FieldLbl Name] -> [FastString]
forall a b. (a -> b) -> a -> b
$ ConLike -> [FieldLbl Name]
conLikeFieldLabels ConLike
con1
              con1_tv_tys :: [TcSigmaType]
con1_tv_tys = [Id] -> [TcSigmaType]
mkTyVarTys [Id]
con1_tvs
              con1_res_ty :: TcSigmaType
con1_res_ty = case Maybe TyCon
mtycon of
                              Just TyCon
tc -> TyCon -> [TcSigmaType] -> TcSigmaType
mkFamilyTyConApp TyCon
tc [TcSigmaType]
con1_tv_tys
                              Maybe TyCon
Nothing -> ConLike -> [TcSigmaType] -> TcSigmaType
conLikeResTy ConLike
con1 [TcSigmaType]
con1_tv_tys

        -- Check that we're not dealing with a unidirectional pattern
        -- synonym
        ; Bool -> TcRn () -> TcRn ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless (Maybe Id -> Bool
forall a. Maybe a -> Bool
isJust (Maybe Id -> Bool) -> Maybe Id -> Bool
forall a b. (a -> b) -> a -> b
$ ConLike -> Maybe Id
conLikeWrapId_maybe ConLike
con1)
                 (Name -> TcRn ()
forall name a. Outputable name => name -> TcM a
nonBidirectionalErr (ConLike -> Name
conLikeName ConLike
con1))

        -- STEP 3    Note [Criteria for update]
        -- Check that each updated field is polymorphic; that is, its type
        -- mentions only the universally-quantified variables of the data con
        ; let flds1_w_tys :: [(FastString, TcSigmaType)]
flds1_w_tys  = String
-> [FastString] -> [TcSigmaType] -> [(FastString, TcSigmaType)]
forall a b. String -> [a] -> [b] -> [(a, b)]
zipEqual String
"tcExpr:RecConUpd" [FastString]
con1_flds [TcSigmaType]
con1_arg_tys
              bad_upd_flds :: [(FastString, TcSigmaType)]
bad_upd_flds = ((FastString, TcSigmaType) -> Bool)
-> [(FastString, TcSigmaType)] -> [(FastString, TcSigmaType)]
forall a. (a -> Bool) -> [a] -> [a]
filter (FastString, TcSigmaType) -> Bool
bad_fld [(FastString, TcSigmaType)]
flds1_w_tys
              con1_tv_set :: VarSet
con1_tv_set  = [Id] -> VarSet
mkVarSet [Id]
con1_tvs
              bad_fld :: (FastString, TcSigmaType) -> Bool
bad_fld (FastString
fld, TcSigmaType
ty) = FastString
fld FastString -> [FastString] -> Bool
forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
`elem` [FastString]
upd_fld_occs Bool -> Bool -> Bool
&&
                                      Bool -> Bool
not (TcSigmaType -> VarSet
tyCoVarsOfType TcSigmaType
ty VarSet -> VarSet -> Bool
`subVarSet` VarSet
con1_tv_set)
        ; Bool -> SDoc -> TcRn ()
checkTc ([(FastString, TcSigmaType)] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [(FastString, TcSigmaType)]
bad_upd_flds) ([(FastString, TcSigmaType)] -> SDoc
badFieldTypes [(FastString, TcSigmaType)]
bad_upd_flds)

        -- STEP 4  Note [Type of a record update]
        -- Figure out types for the scrutinee and result
        -- Both are of form (T a b c), with fresh type variables, but with
        -- common variables where the scrutinee and result must have the same type
        -- These are variables that appear in *any* arg of *any* of the
        -- relevant constructors *except* in the updated fields
        --
        ; let fixed_tvs :: VarSet
fixed_tvs = [FastString] -> [Id] -> [ConLike] -> VarSet
getFixedTyVars [FastString]
upd_fld_occs [Id]
con1_tvs [ConLike]
relevant_cons
              is_fixed_tv :: Id -> Bool
is_fixed_tv Id
tv = Id
tv Id -> VarSet -> Bool
`elemVarSet` VarSet
fixed_tvs

              mk_inst_ty :: TCvSubst -> (TyVar, TcType) -> TcM (TCvSubst, TcType)
              -- Deals with instantiation of kind variables
              --   c.f. GHC.Tc.Utils.TcMType.newMetaTyVars
              mk_inst_ty :: TCvSubst -> (Id, TcSigmaType) -> TcM (TCvSubst, TcSigmaType)
mk_inst_ty TCvSubst
subst (Id
tv, TcSigmaType
result_inst_ty)
                | Id -> Bool
is_fixed_tv Id
tv   -- Same as result type
                = (TCvSubst, TcSigmaType) -> TcM (TCvSubst, TcSigmaType)
forall (m :: * -> *) a. Monad m => a -> m a
return (TCvSubst -> Id -> TcSigmaType -> TCvSubst
extendTvSubst TCvSubst
subst Id
tv TcSigmaType
result_inst_ty, TcSigmaType
result_inst_ty)
                | Bool
otherwise        -- Fresh type, of correct kind
                = do { (TCvSubst
subst', Id
new_tv) <- TCvSubst -> Id -> TcM (TCvSubst, Id)
newMetaTyVarX TCvSubst
subst Id
tv
                     ; (TCvSubst, TcSigmaType) -> TcM (TCvSubst, TcSigmaType)
forall (m :: * -> *) a. Monad m => a -> m a
return (TCvSubst
subst', Id -> TcSigmaType
mkTyVarTy Id
new_tv) }

        ; (TCvSubst
result_subst, [Id]
con1_tvs') <- [Id] -> TcM (TCvSubst, [Id])
newMetaTyVars [Id]
con1_tvs
        ; let result_inst_tys :: [TcSigmaType]
result_inst_tys = [Id] -> [TcSigmaType]
mkTyVarTys [Id]
con1_tvs'
              init_subst :: TCvSubst
init_subst = InScopeSet -> TCvSubst
mkEmptyTCvSubst (TCvSubst -> InScopeSet
getTCvInScope TCvSubst
result_subst)

        ; (TCvSubst
scrut_subst, [TcSigmaType]
scrut_inst_tys) <- (TCvSubst -> (Id, TcSigmaType) -> TcM (TCvSubst, TcSigmaType))
-> TCvSubst
-> [(Id, TcSigmaType)]
-> IOEnv (Env TcGblEnv TcLclEnv) (TCvSubst, [TcSigmaType])
forall (m :: * -> *) acc x y.
Monad m =>
(acc -> x -> m (acc, y)) -> acc -> [x] -> m (acc, [y])
mapAccumLM TCvSubst -> (Id, TcSigmaType) -> TcM (TCvSubst, TcSigmaType)
mk_inst_ty TCvSubst
init_subst
                                                      ([Id]
con1_tvs [Id] -> [TcSigmaType] -> [(Id, TcSigmaType)]
forall a b. [a] -> [b] -> [(a, b)]
`zip` [TcSigmaType]
result_inst_tys)

        ; let rec_res_ty :: TcSigmaType
rec_res_ty    = HasCallStack => TCvSubst -> TcSigmaType -> TcSigmaType
TCvSubst -> TcSigmaType -> TcSigmaType
TcType.substTy TCvSubst
result_subst TcSigmaType
con1_res_ty
              scrut_ty :: TcSigmaType
scrut_ty      = HasCallStack => TCvSubst -> TcSigmaType -> TcSigmaType
TCvSubst -> TcSigmaType -> TcSigmaType
TcType.substTy TCvSubst
scrut_subst  TcSigmaType
con1_res_ty
              con1_arg_tys' :: [TcSigmaType]
con1_arg_tys' = (TcSigmaType -> TcSigmaType) -> [TcSigmaType] -> [TcSigmaType]
forall a b. (a -> b) -> [a] -> [b]
map (HasCallStack => TCvSubst -> TcSigmaType -> TcSigmaType
TCvSubst -> TcSigmaType -> TcSigmaType
TcType.substTy TCvSubst
result_subst) [TcSigmaType]
con1_arg_tys

        ; TcCoercionR
co_scrut <- Maybe SDoc -> TcSigmaType -> TcSigmaType -> TcM TcCoercionR
unifyType (SDoc -> Maybe SDoc
forall a. a -> Maybe a
Just (GenLocated SrcSpan (HsExpr GhcRn) -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
record_expr)) TcSigmaType
record_rho TcSigmaType
scrut_ty
                -- NB: normal unification is OK here (as opposed to subsumption),
                -- because for this to work out, both record_rho and scrut_ty have
                -- to be normal datatypes -- no contravariant stuff can go on

        -- STEP 5
        -- Typecheck the bindings
        ; [Located
   (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))]
rbinds'      <- ConLike
-> [TcSigmaType]
-> [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
-> TcM [LHsRecUpdField GhcTc]
tcRecordUpd ConLike
con1 [TcSigmaType]
con1_arg_tys' [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
rbinds

        -- STEP 6: Deal with the stupid theta
        ; let theta' :: [TcSigmaType]
theta' = TCvSubst -> [TcSigmaType] -> [TcSigmaType]
substThetaUnchecked TCvSubst
scrut_subst (ConLike -> [TcSigmaType]
conLikeStupidTheta ConLike
con1)
        ; CtOrigin -> [TcSigmaType] -> TcRn ()
instStupidTheta CtOrigin
RecordUpdOrigin [TcSigmaType]
theta'

        -- Step 7: make a cast for the scrutinee, in the
        --         case that it's from a data family
        ; let fam_co :: HsWrapper   -- RepT t1 .. tn ~R scrut_ty
              fam_co :: HsWrapper
fam_co | Just TyCon
tycon <- Maybe TyCon
mtycon
                     , Just CoAxiom Unbranched
co_con <- TyCon -> Maybe (CoAxiom Unbranched)
tyConFamilyCoercion_maybe TyCon
tycon
                     = TcCoercionR -> HsWrapper
mkWpCastR (CoAxiom Unbranched -> [TcSigmaType] -> [TcCoercionR] -> TcCoercionR
mkTcUnbranchedAxInstCo CoAxiom Unbranched
co_con [TcSigmaType]
scrut_inst_tys [])
                     | Bool
otherwise
                     = HsWrapper
idHsWrapper

        -- Step 8: Check that the req constraints are satisfied
        -- For normal data constructors req_theta is empty but we must do
        -- this check for pattern synonyms.
        ; let req_theta' :: [TcSigmaType]
req_theta' = TCvSubst -> [TcSigmaType] -> [TcSigmaType]
substThetaUnchecked TCvSubst
scrut_subst [TcSigmaType]
req_theta
        ; HsWrapper
req_wrap <- CtOrigin -> [TcSigmaType] -> TcM HsWrapper
instCallConstraints CtOrigin
RecordUpdOrigin [TcSigmaType]
req_theta'

        -- Phew!
        ; let upd_tc :: RecordUpdTc
upd_tc = RecordUpdTc :: [ConLike]
-> [TcSigmaType] -> [TcSigmaType] -> HsWrapper -> RecordUpdTc
RecordUpdTc { rupd_cons :: [ConLike]
rupd_cons = [ConLike]
relevant_cons
                                   , rupd_in_tys :: [TcSigmaType]
rupd_in_tys = [TcSigmaType]
scrut_inst_tys
                                   , rupd_out_tys :: [TcSigmaType]
rupd_out_tys = [TcSigmaType]
result_inst_tys
                                   , rupd_wrap :: HsWrapper
rupd_wrap = HsWrapper
req_wrap }
              expr' :: HsExpr GhcTc
expr' = RecordUpd :: forall p.
XRecordUpd p -> LHsExpr p -> [LHsRecUpdField p] -> HsExpr p
RecordUpd { rupd_expr :: LHsExpr GhcTc
rupd_expr = HsWrapper -> LHsExpr GhcTc -> LHsExpr GhcTc
mkLHsWrap HsWrapper
fam_co (LHsExpr GhcTc -> LHsExpr GhcTc) -> LHsExpr GhcTc -> LHsExpr GhcTc
forall a b. (a -> b) -> a -> b
$
                                              TcCoercionR -> LHsExpr GhcTc -> LHsExpr GhcTc
mkLHsWrapCo TcCoercionR
co_scrut Located (HsExpr GhcTc)
LHsExpr GhcTc
record_expr'
                                , rupd_flds :: [LHsRecUpdField GhcTc]
rupd_flds = [Located
   (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))]
[LHsRecUpdField GhcTc]
rbinds'
                                , rupd_ext :: XRecordUpd GhcTc
rupd_ext = RecordUpdTc
XRecordUpd GhcTc
upd_tc }

        ; HsExpr GhcRn
-> HsExpr GhcTc
-> TcSigmaType
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcWrapResult HsExpr GhcRn
expr HsExpr GhcTc
expr' TcSigmaType
rec_res_ty ExpSigmaType
res_ty }


{-
************************************************************************
*                                                                      *
        Arithmetic sequences                    e.g. [a,b..]
        and their parallel-array counterparts   e.g. [: a,b.. :]

*                                                                      *
************************************************************************
-}

tcExpr (ArithSeq XArithSeq GhcRn
_ Maybe (SyntaxExpr GhcRn)
witness ArithSeqInfo GhcRn
seq) ExpSigmaType
res_ty
  = Maybe (SyntaxExpr GhcRn)
-> ArithSeqInfo GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcArithSeq Maybe (SyntaxExpr GhcRn)
witness ArithSeqInfo GhcRn
seq ExpSigmaType
res_ty

{-
************************************************************************
*                                                                      *
                Template Haskell
*                                                                      *
************************************************************************
-}

-- HsSpliced is an annotation produced by 'GHC.Rename.Splice.rnSpliceExpr'.
-- Here we get rid of it and add the finalizers to the global environment.
--
-- See Note [Delaying modFinalizers in untyped splices] in GHC.Rename.Splice.
tcExpr (HsSpliceE XSpliceE GhcRn
_ (HsSpliced XSpliced GhcRn
_ ThModFinalizers
mod_finalizers (HsSplicedExpr HsExpr GhcRn
expr)))
       ExpSigmaType
res_ty
  = do ThModFinalizers -> TcRn ()
addModFinalizersWithLclEnv ThModFinalizers
mod_finalizers
       HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr HsExpr GhcRn
expr ExpSigmaType
res_ty
tcExpr (HsSpliceE XSpliceE GhcRn
_ HsSplice GhcRn
splice)          ExpSigmaType
res_ty = HsSplice GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcSpliceExpr HsSplice GhcRn
splice ExpSigmaType
res_ty
tcExpr e :: HsExpr GhcRn
e@(HsBracket XBracket GhcRn
_ HsBracket GhcRn
brack)         ExpSigmaType
res_ty = HsExpr GhcRn
-> HsBracket GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcTypedBracket HsExpr GhcRn
e HsBracket GhcRn
brack ExpSigmaType
res_ty
tcExpr e :: HsExpr GhcRn
e@(HsRnBracketOut XRnBracketOut GhcRn
_ HsBracket GhcRn
brack [PendingRnSplice]
ps) ExpSigmaType
res_ty = HsExpr GhcRn
-> HsBracket GhcRn
-> [PendingRnSplice]
-> ExpSigmaType
-> TcM (HsExpr GhcTc)
tcUntypedBracket HsExpr GhcRn
e HsBracket GhcRn
brack [PendingRnSplice]
ps ExpSigmaType
res_ty

{-
************************************************************************
*                                                                      *
                Rebindable syntax
*                                                                      *
************************************************************************
-}

-- See Note [Rebindable syntax and HsExpansion].
tcExpr (XExpr (HsExpanded a b)) ExpSigmaType
t
  = (HsExpr GhcTc -> HsExpr GhcTc)
-> TcM (HsExpr GhcTc) -> TcM (HsExpr GhcTc)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (XXExprGhcTc -> HsExpr GhcTc
forall p. XXExpr p -> HsExpr p
XExpr (XXExprGhcTc -> HsExpr GhcTc)
-> (HsExpr GhcTc -> XXExprGhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. HsExpansion (HsExpr GhcRn) (HsExpr GhcTc) -> XXExprGhcTc
ExpansionExpr (HsExpansion (HsExpr GhcRn) (HsExpr GhcTc) -> XXExprGhcTc)
-> (HsExpr GhcTc -> HsExpansion (HsExpr GhcRn) (HsExpr GhcTc))
-> HsExpr GhcTc
-> XXExprGhcTc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. HsExpr GhcRn
-> HsExpr GhcTc -> HsExpansion (HsExpr GhcRn) (HsExpr GhcTc)
forall a b. a -> b -> HsExpansion a b
HsExpanded HsExpr GhcRn
a) (TcM (HsExpr GhcTc) -> TcM (HsExpr GhcTc))
-> TcM (HsExpr GhcTc) -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$
      SrcSpan -> TcM (HsExpr GhcTc) -> TcM (HsExpr GhcTc)
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
generatedSrcSpan (HsExpr GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcExpr HsExpr GhcRn
b ExpSigmaType
t)

{-
************************************************************************
*                                                                      *
                Catch-all
*                                                                      *
************************************************************************
-}

tcExpr HsExpr GhcRn
other ExpSigmaType
_ = String -> SDoc -> TcM (HsExpr GhcTc)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"tcExpr" (HsExpr GhcRn -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcRn
other)
  -- Include ArrForm, ArrApp, which shouldn't appear at all
  -- Also HsTcBracketOut, HsQuasiQuoteE


{-
************************************************************************
*                                                                      *
                Arithmetic sequences [a..b] etc
*                                                                      *
************************************************************************
-}

tcArithSeq :: Maybe (SyntaxExpr GhcRn) -> ArithSeqInfo GhcRn -> ExpRhoType
           -> TcM (HsExpr GhcTc)

tcArithSeq :: Maybe (SyntaxExpr GhcRn)
-> ArithSeqInfo GhcRn -> ExpSigmaType -> TcM (HsExpr GhcTc)
tcArithSeq Maybe (SyntaxExpr GhcRn)
witness seq :: ArithSeqInfo GhcRn
seq@(From LHsExpr GhcRn
expr) ExpSigmaType
res_ty
  = do { (HsWrapper
wrap, TcSigmaType
elt_mult, TcSigmaType
elt_ty, Maybe SyntaxExprTc
wit') <- Maybe (SyntaxExpr GhcRn)
-> ExpSigmaType
-> TcM
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe (SyntaxExpr GhcTc))
arithSeqEltType Maybe (SyntaxExpr GhcRn)
witness ExpSigmaType
res_ty
       ; Located (HsExpr GhcTc)
expr' <-TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr TcSigmaType
elt_ty
       ; HsExpr GhcTc
enum_from <- CtOrigin -> Name -> [TcSigmaType] -> TcM (HsExpr GhcTc)
newMethodFromName (ArithSeqInfo GhcRn -> CtOrigin
ArithSeqOrigin ArithSeqInfo GhcRn
seq)
                              Name
enumFromName [TcSigmaType
elt_ty]
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$
         XArithSeq GhcTc
-> Maybe (SyntaxExpr GhcTc) -> ArithSeqInfo GhcTc -> HsExpr GhcTc
forall p.
XArithSeq p -> Maybe (SyntaxExpr p) -> ArithSeqInfo p -> HsExpr p
ArithSeq HsExpr GhcTc
XArithSeq GhcTc
enum_from Maybe SyntaxExprTc
Maybe (SyntaxExpr GhcTc)
wit' (LHsExpr GhcTc -> ArithSeqInfo GhcTc
forall id. LHsExpr id -> ArithSeqInfo id
From Located (HsExpr GhcTc)
LHsExpr GhcTc
expr') }

tcArithSeq Maybe (SyntaxExpr GhcRn)
witness seq :: ArithSeqInfo GhcRn
seq@(FromThen LHsExpr GhcRn
expr1 LHsExpr GhcRn
expr2) ExpSigmaType
res_ty
  = do { (HsWrapper
wrap, TcSigmaType
elt_mult, TcSigmaType
elt_ty, Maybe SyntaxExprTc
wit') <- Maybe (SyntaxExpr GhcRn)
-> ExpSigmaType
-> TcM
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe (SyntaxExpr GhcTc))
arithSeqEltType Maybe (SyntaxExpr GhcRn)
witness ExpSigmaType
res_ty
       ; Located (HsExpr GhcTc)
expr1' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr1 TcSigmaType
elt_ty
       ; Located (HsExpr GhcTc)
expr2' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr2 TcSigmaType
elt_ty
       ; HsExpr GhcTc
enum_from_then <- CtOrigin -> Name -> [TcSigmaType] -> TcM (HsExpr GhcTc)
newMethodFromName (ArithSeqInfo GhcRn -> CtOrigin
ArithSeqOrigin ArithSeqInfo GhcRn
seq)
                              Name
enumFromThenName [TcSigmaType
elt_ty]
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$
         XArithSeq GhcTc
-> Maybe (SyntaxExpr GhcTc) -> ArithSeqInfo GhcTc -> HsExpr GhcTc
forall p.
XArithSeq p -> Maybe (SyntaxExpr p) -> ArithSeqInfo p -> HsExpr p
ArithSeq HsExpr GhcTc
XArithSeq GhcTc
enum_from_then Maybe SyntaxExprTc
Maybe (SyntaxExpr GhcTc)
wit' (LHsExpr GhcTc -> LHsExpr GhcTc -> ArithSeqInfo GhcTc
forall id. LHsExpr id -> LHsExpr id -> ArithSeqInfo id
FromThen Located (HsExpr GhcTc)
LHsExpr GhcTc
expr1' Located (HsExpr GhcTc)
LHsExpr GhcTc
expr2') }

tcArithSeq Maybe (SyntaxExpr GhcRn)
witness seq :: ArithSeqInfo GhcRn
seq@(FromTo LHsExpr GhcRn
expr1 LHsExpr GhcRn
expr2) ExpSigmaType
res_ty
  = do { (HsWrapper
wrap, TcSigmaType
elt_mult, TcSigmaType
elt_ty, Maybe SyntaxExprTc
wit') <- Maybe (SyntaxExpr GhcRn)
-> ExpSigmaType
-> TcM
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe (SyntaxExpr GhcTc))
arithSeqEltType Maybe (SyntaxExpr GhcRn)
witness ExpSigmaType
res_ty
       ; Located (HsExpr GhcTc)
expr1' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr1 TcSigmaType
elt_ty
       ; Located (HsExpr GhcTc)
expr2' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr2 TcSigmaType
elt_ty
       ; HsExpr GhcTc
enum_from_to <- CtOrigin -> Name -> [TcSigmaType] -> TcM (HsExpr GhcTc)
newMethodFromName (ArithSeqInfo GhcRn -> CtOrigin
ArithSeqOrigin ArithSeqInfo GhcRn
seq)
                              Name
enumFromToName [TcSigmaType
elt_ty]
       ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$
         XArithSeq GhcTc
-> Maybe (SyntaxExpr GhcTc) -> ArithSeqInfo GhcTc -> HsExpr GhcTc
forall p.
XArithSeq p -> Maybe (SyntaxExpr p) -> ArithSeqInfo p -> HsExpr p
ArithSeq HsExpr GhcTc
XArithSeq GhcTc
enum_from_to Maybe SyntaxExprTc
Maybe (SyntaxExpr GhcTc)
wit' (LHsExpr GhcTc -> LHsExpr GhcTc -> ArithSeqInfo GhcTc
forall id. LHsExpr id -> LHsExpr id -> ArithSeqInfo id
FromTo Located (HsExpr GhcTc)
LHsExpr GhcTc
expr1' Located (HsExpr GhcTc)
LHsExpr GhcTc
expr2') }

tcArithSeq Maybe (SyntaxExpr GhcRn)
witness seq :: ArithSeqInfo GhcRn
seq@(FromThenTo LHsExpr GhcRn
expr1 LHsExpr GhcRn
expr2 LHsExpr GhcRn
expr3) ExpSigmaType
res_ty
  = do { (HsWrapper
wrap, TcSigmaType
elt_mult, TcSigmaType
elt_ty, Maybe SyntaxExprTc
wit') <- Maybe (SyntaxExpr GhcRn)
-> ExpSigmaType
-> TcM
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe (SyntaxExpr GhcTc))
arithSeqEltType Maybe (SyntaxExpr GhcRn)
witness ExpSigmaType
res_ty
        ; Located (HsExpr GhcTc)
expr1' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr1 TcSigmaType
elt_ty
        ; Located (HsExpr GhcTc)
expr2' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr2 TcSigmaType
elt_ty
        ; Located (HsExpr GhcTc)
expr3' <- TcSigmaType
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a. TcSigmaType -> TcM a -> TcM a
tcScalingUsage TcSigmaType
elt_mult (TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc)))
-> TcRn (Located (HsExpr GhcTc)) -> TcRn (Located (HsExpr GhcTc))
forall a b. (a -> b) -> a -> b
$ LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr3 TcSigmaType
elt_ty
        ; HsExpr GhcTc
eft <- CtOrigin -> Name -> [TcSigmaType] -> TcM (HsExpr GhcTc)
newMethodFromName (ArithSeqInfo GhcRn -> CtOrigin
ArithSeqOrigin ArithSeqInfo GhcRn
seq)
                              Name
enumFromThenToName [TcSigmaType
elt_ty]
        ; HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsExpr GhcTc -> TcM (HsExpr GhcTc))
-> HsExpr GhcTc -> TcM (HsExpr GhcTc)
forall a b. (a -> b) -> a -> b
$ HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
wrap (HsExpr GhcTc -> HsExpr GhcTc) -> HsExpr GhcTc -> HsExpr GhcTc
forall a b. (a -> b) -> a -> b
$
          XArithSeq GhcTc
-> Maybe (SyntaxExpr GhcTc) -> ArithSeqInfo GhcTc -> HsExpr GhcTc
forall p.
XArithSeq p -> Maybe (SyntaxExpr p) -> ArithSeqInfo p -> HsExpr p
ArithSeq HsExpr GhcTc
XArithSeq GhcTc
eft Maybe SyntaxExprTc
Maybe (SyntaxExpr GhcTc)
wit' (LHsExpr GhcTc
-> LHsExpr GhcTc -> LHsExpr GhcTc -> ArithSeqInfo GhcTc
forall id.
LHsExpr id -> LHsExpr id -> LHsExpr id -> ArithSeqInfo id
FromThenTo Located (HsExpr GhcTc)
LHsExpr GhcTc
expr1' Located (HsExpr GhcTc)
LHsExpr GhcTc
expr2' Located (HsExpr GhcTc)
LHsExpr GhcTc
expr3') }

-----------------
arithSeqEltType :: Maybe (SyntaxExpr GhcRn) -> ExpRhoType
                -> TcM (HsWrapper, Mult, TcType, Maybe (SyntaxExpr GhcTc))
arithSeqEltType :: Maybe (SyntaxExpr GhcRn)
-> ExpSigmaType
-> TcM
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe (SyntaxExpr GhcTc))
arithSeqEltType Maybe (SyntaxExpr GhcRn)
Nothing ExpSigmaType
res_ty
  = do { TcSigmaType
res_ty <- ExpSigmaType -> TcM TcSigmaType
expTypeToType ExpSigmaType
res_ty
       ; (TcCoercionR
coi, TcSigmaType
elt_ty) <- TcSigmaType -> TcM (TcCoercionR, TcSigmaType)
matchExpectedListTy TcSigmaType
res_ty
       ; (HsWrapper, TcSigmaType, TcSigmaType, Maybe SyntaxExprTc)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe SyntaxExprTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (TcCoercionR -> HsWrapper
mkWpCastN TcCoercionR
coi, TcSigmaType
One, TcSigmaType
elt_ty, Maybe SyntaxExprTc
forall a. Maybe a
Nothing) }
arithSeqEltType (Just SyntaxExpr GhcRn
fl) ExpSigmaType
res_ty
  = do { ((TcSigmaType
elt_mult, TcSigmaType
elt_ty), SyntaxExprTc
fl')
           <- CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcM (TcSigmaType, TcSigmaType))
-> TcM ((TcSigmaType, TcSigmaType), SyntaxExprTc)
forall a.
CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
tcSyntaxOp CtOrigin
ListOrigin SyntaxExprRn
SyntaxExpr GhcRn
fl [SyntaxOpType
SynList] ExpSigmaType
res_ty (([TcSigmaType] -> [TcSigmaType] -> TcM (TcSigmaType, TcSigmaType))
 -> TcM ((TcSigmaType, TcSigmaType), SyntaxExprTc))
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcM (TcSigmaType, TcSigmaType))
-> TcM ((TcSigmaType, TcSigmaType), SyntaxExprTc)
forall a b. (a -> b) -> a -> b
$
              \ [TcSigmaType
elt_ty] [TcSigmaType
elt_mult] -> (TcSigmaType, TcSigmaType) -> TcM (TcSigmaType, TcSigmaType)
forall (m :: * -> *) a. Monad m => a -> m a
return (TcSigmaType
elt_mult, TcSigmaType
elt_ty)
       ; (HsWrapper, TcSigmaType, TcSigmaType, Maybe SyntaxExprTc)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (HsWrapper, TcSigmaType, TcSigmaType, Maybe SyntaxExprTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (HsWrapper
idHsWrapper, TcSigmaType
elt_mult, TcSigmaType
elt_ty, SyntaxExprTc -> Maybe SyntaxExprTc
forall a. a -> Maybe a
Just SyntaxExprTc
fl') }

----------------
tcTupArgs :: [LHsTupArg GhcRn] -> [TcSigmaType] -> TcM [LHsTupArg GhcTc]
tcTupArgs :: [LHsTupArg GhcRn] -> [TcSigmaType] -> TcM [LHsTupArg GhcTc]
tcTupArgs [LHsTupArg GhcRn]
args [TcSigmaType]
tys
  = do MASSERT( equalLength args tys )
       Int -> TcRn ()
checkTupSize ([Located (HsTupArg GhcRn)] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [Located (HsTupArg GhcRn)]
[LHsTupArg GhcRn]
args)
       ((Located (HsTupArg GhcRn), TcSigmaType)
 -> IOEnv (Env TcGblEnv TcLclEnv) (Located (HsTupArg GhcTc)))
-> [(Located (HsTupArg GhcRn), TcSigmaType)]
-> IOEnv (Env TcGblEnv TcLclEnv) [Located (HsTupArg GhcTc)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (Located (HsTupArg GhcRn), TcSigmaType)
-> IOEnv (Env TcGblEnv TcLclEnv) (Located (HsTupArg GhcTc))
forall l.
(GenLocated l (HsTupArg GhcRn), TcSigmaType)
-> IOEnv (Env TcGblEnv TcLclEnv) (GenLocated l (HsTupArg GhcTc))
go ([Located (HsTupArg GhcRn)]
[LHsTupArg GhcRn]
args [Located (HsTupArg GhcRn)]
-> [TcSigmaType] -> [(Located (HsTupArg GhcRn), TcSigmaType)]
forall a b. [a] -> [b] -> [(a, b)]
`zip` [TcSigmaType]
tys)
  where
    go :: (GenLocated l (HsTupArg GhcRn), TcSigmaType)
-> IOEnv (Env TcGblEnv TcLclEnv) (GenLocated l (HsTupArg GhcTc))
go (L l
l (Missing {}),     TcSigmaType
arg_ty) = do { TcSigmaType
mult <- TcSigmaType -> TcM TcSigmaType
newFlexiTyVarTy TcSigmaType
multiplicityTy
                                           ; GenLocated l (HsTupArg GhcTc)
-> IOEnv (Env TcGblEnv TcLclEnv) (GenLocated l (HsTupArg GhcTc))
forall (m :: * -> *) a. Monad m => a -> m a
return (l -> HsTupArg GhcTc -> GenLocated l (HsTupArg GhcTc)
forall l e. l -> e -> GenLocated l e
L l
l (XMissing GhcTc -> HsTupArg GhcTc
forall id. XMissing id -> HsTupArg id
Missing (TcSigmaType -> TcSigmaType -> Scaled TcSigmaType
forall a. TcSigmaType -> a -> Scaled a
Scaled TcSigmaType
mult TcSigmaType
arg_ty))) }
    go (L l
l (Present XPresent GhcRn
x LHsExpr GhcRn
expr), TcSigmaType
arg_ty) = do { Located (HsExpr GhcTc)
expr' <- LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExpr LHsExpr GhcRn
expr TcSigmaType
arg_ty
                                           ; GenLocated l (HsTupArg GhcTc)
-> IOEnv (Env TcGblEnv TcLclEnv) (GenLocated l (HsTupArg GhcTc))
forall (m :: * -> *) a. Monad m => a -> m a
return (l -> HsTupArg GhcTc -> GenLocated l (HsTupArg GhcTc)
forall l e. l -> e -> GenLocated l e
L l
l (XPresent GhcTc -> LHsExpr GhcTc -> HsTupArg GhcTc
forall id. XPresent id -> LHsExpr id -> HsTupArg id
Present XPresent GhcRn
XPresent GhcTc
x Located (HsExpr GhcTc)
LHsExpr GhcTc
expr')) }

---------------------------
-- See TcType.SyntaxOpType also for commentary
tcSyntaxOp :: CtOrigin
           -> SyntaxExprRn
           -> [SyntaxOpType]           -- ^ shape of syntax operator arguments
           -> ExpRhoType               -- ^ overall result type
           -> ([TcSigmaType] -> [Mult] -> TcM a) -- ^ Type check any arguments,
                                                 -- takes a type per hole and a
                                                 -- multiplicity per arrow in
                                                 -- the shape.
           -> TcM (a, SyntaxExprTc)
-- ^ Typecheck a syntax operator
-- The operator is a variable or a lambda at this stage (i.e. renamer
-- output)t
tcSyntaxOp :: CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> ExpSigmaType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
tcSyntaxOp CtOrigin
orig SyntaxExprRn
expr [SyntaxOpType]
arg_tys ExpSigmaType
res_ty
  = CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
forall a.
CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
tcSyntaxOpGen CtOrigin
orig SyntaxExprRn
expr [SyntaxOpType]
arg_tys (ExpSigmaType -> SyntaxOpType
SynType ExpSigmaType
res_ty)

-- | Slightly more general version of 'tcSyntaxOp' that allows the caller
-- to specify the shape of the result of the syntax operator
tcSyntaxOpGen :: CtOrigin
              -> SyntaxExprRn
              -> [SyntaxOpType]
              -> SyntaxOpType
              -> ([TcSigmaType] -> [Mult] -> TcM a)
              -> TcM (a, SyntaxExprTc)
tcSyntaxOpGen :: CtOrigin
-> SyntaxExprRn
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, SyntaxExprTc)
tcSyntaxOpGen CtOrigin
orig (SyntaxExprRn HsExpr GhcRn
op) [SyntaxOpType]
arg_tys SyntaxOpType
res_ty [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside
  = do { (HsExpr GhcTc
expr, TcSigmaType
sigma) <- HsExpr GhcRn
-> [HsExprArg 'TcpRn]
-> Maybe TcSigmaType
-> TcM (HsExpr GhcTc, TcSigmaType)
tcInferAppHead HsExpr GhcRn
op [] Maybe TcSigmaType
forall a. Maybe a
Nothing
             -- Nothing here might be improved, but all this
             -- code is scheduled for demolition anyway
       ; String -> SDoc -> TcRn ()
traceTc String
"tcSyntaxOpGen" (HsExpr GhcRn -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcRn
op SDoc -> SDoc -> SDoc
$$ HsExpr GhcTc -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcTc
expr SDoc -> SDoc -> SDoc
$$ TcSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr TcSigmaType
sigma)
       ; (a
result, HsWrapper
expr_wrap, [HsWrapper]
arg_wraps, HsWrapper
res_wrap)
           <- CtOrigin
-> TcSigmaType
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
forall a.
CtOrigin
-> TcSigmaType
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
tcSynArgA CtOrigin
orig TcSigmaType
sigma [SyntaxOpType]
arg_tys SyntaxOpType
res_ty (([TcSigmaType] -> [TcSigmaType] -> TcM a)
 -> TcM (a, HsWrapper, [HsWrapper], HsWrapper))
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
forall a b. (a -> b) -> a -> b
$
              [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside
       ; String -> SDoc -> TcRn ()
traceTc String
"tcSyntaxOpGen" (HsExpr GhcRn -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcRn
op SDoc -> SDoc -> SDoc
$$ HsExpr GhcTc -> SDoc
forall a. Outputable a => a -> SDoc
ppr HsExpr GhcTc
expr SDoc -> SDoc -> SDoc
$$ TcSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr TcSigmaType
sigma )
       ; (a, SyntaxExprTc) -> TcM (a, SyntaxExprTc)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, SyntaxExprTc :: HsExpr GhcTc -> [HsWrapper] -> HsWrapper -> SyntaxExprTc
SyntaxExprTc { syn_expr :: HsExpr GhcTc
syn_expr = HsWrapper -> HsExpr GhcTc -> HsExpr GhcTc
mkHsWrap HsWrapper
expr_wrap HsExpr GhcTc
expr
                                      , syn_arg_wraps :: [HsWrapper]
syn_arg_wraps = [HsWrapper]
arg_wraps
                                      , syn_res_wrap :: HsWrapper
syn_res_wrap  = HsWrapper
res_wrap }) }
tcSyntaxOpGen CtOrigin
_ SyntaxExprRn
NoSyntaxExprRn [SyntaxOpType]
_ SyntaxOpType
_ [TcSigmaType] -> [TcSigmaType] -> TcM a
_ = String -> TcM (a, SyntaxExprTc)
forall a. String -> a
panic String
"tcSyntaxOpGen"

{-
Note [tcSynArg]
~~~~~~~~~~~~~~~
Because of the rich structure of SyntaxOpType, we must do the
contra-/covariant thing when working down arrows, to get the
instantiation vs. skolemisation decisions correct (and, more
obviously, the orientation of the HsWrappers). We thus have
two tcSynArgs.
-}

-- works on "expected" types, skolemising where necessary
-- See Note [tcSynArg]
tcSynArgE :: CtOrigin
          -> TcSigmaType
          -> SyntaxOpType                -- ^ shape it is expected to have
          -> ([TcSigmaType] -> [Mult] -> TcM a) -- ^ check the arguments
          -> TcM (a, HsWrapper)
           -- ^ returns a wrapper :: (type of right shape) "->" (type passed in)
tcSynArgE :: CtOrigin
-> TcSigmaType
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper)
tcSynArgE CtOrigin
orig TcSigmaType
sigma_ty SyntaxOpType
syn_ty [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside
  = do { (HsWrapper
skol_wrap, (a
result, HsWrapper
ty_wrapper))
           <- UserTypeCtxt
-> TcSigmaType
-> (TcSigmaType -> TcM (a, HsWrapper))
-> TcM (HsWrapper, (a, HsWrapper))
forall result.
UserTypeCtxt
-> TcSigmaType
-> (TcSigmaType -> TcM result)
-> TcM (HsWrapper, result)
tcSkolemise UserTypeCtxt
GenSigCtxt TcSigmaType
sigma_ty ((TcSigmaType -> TcM (a, HsWrapper))
 -> TcM (HsWrapper, (a, HsWrapper)))
-> (TcSigmaType -> TcM (a, HsWrapper))
-> TcM (HsWrapper, (a, HsWrapper))
forall a b. (a -> b) -> a -> b
$ \ TcSigmaType
rho_ty ->
              TcSigmaType -> SyntaxOpType -> TcM (a, HsWrapper)
go TcSigmaType
rho_ty SyntaxOpType
syn_ty
       ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
skol_wrap HsWrapper -> HsWrapper -> HsWrapper
<.> HsWrapper
ty_wrapper) }
    where
    go :: TcSigmaType -> SyntaxOpType -> TcM (a, HsWrapper)
go TcSigmaType
rho_ty SyntaxOpType
SynAny
      = do { a
result <- [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside [TcSigmaType
rho_ty] []
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
idHsWrapper) }

    go TcSigmaType
rho_ty SyntaxOpType
SynRho   -- same as SynAny, because we skolemise eagerly
      = do { a
result <- [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside [TcSigmaType
rho_ty] []
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
idHsWrapper) }

    go TcSigmaType
rho_ty SyntaxOpType
SynList
      = do { (TcCoercionR
list_co, TcSigmaType
elt_ty) <- TcSigmaType -> TcM (TcCoercionR, TcSigmaType)
matchExpectedListTy TcSigmaType
rho_ty
           ; a
result <- [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside [TcSigmaType
elt_ty] []
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, TcCoercionR -> HsWrapper
mkWpCastN TcCoercionR
list_co) }

    go TcSigmaType
rho_ty (SynFun SyntaxOpType
arg_shape SyntaxOpType
res_shape)
      = do { ( HsWrapper
match_wrapper                         -- :: (arg_ty -> res_ty) "->" rho_ty
             , ( ( (a
result, TcSigmaType
arg_ty, TcSigmaType
res_ty, TcSigmaType
op_mult)
                 , HsWrapper
res_wrapper )                     -- :: res_ty_out "->" res_ty
               , HsWrapper
arg_wrapper1, [], HsWrapper
arg_wrapper2 ) )  -- :: arg_ty "->" arg_ty_out
               <- SDoc
-> UserTypeCtxt
-> Int
-> ExpSigmaType
-> ([Scaled ExpSigmaType]
    -> ExpSigmaType
    -> TcM
         (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
          HsWrapper, [HsWrapper], HsWrapper))
-> TcM
     (HsWrapper,
      (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
       HsWrapper, [HsWrapper], HsWrapper))
forall a.
SDoc
-> UserTypeCtxt
-> Int
-> ExpSigmaType
-> ([Scaled ExpSigmaType] -> ExpSigmaType -> TcM a)
-> TcM (HsWrapper, a)
matchExpectedFunTys SDoc
herald UserTypeCtxt
GenSigCtxt Int
1 (TcSigmaType -> ExpSigmaType
mkCheckExpType TcSigmaType
rho_ty) (([Scaled ExpSigmaType]
  -> ExpSigmaType
  -> TcM
       (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
        HsWrapper, [HsWrapper], HsWrapper))
 -> TcM
      (HsWrapper,
       (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
        HsWrapper, [HsWrapper], HsWrapper)))
-> ([Scaled ExpSigmaType]
    -> ExpSigmaType
    -> TcM
         (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
          HsWrapper, [HsWrapper], HsWrapper))
-> TcM
     (HsWrapper,
      (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
       HsWrapper, [HsWrapper], HsWrapper))
forall a b. (a -> b) -> a -> b
$
                  \ [Scaled ExpSigmaType
arg_ty] ExpSigmaType
res_ty ->
                  do { TcSigmaType
arg_tc_ty <- ExpSigmaType -> TcM TcSigmaType
expTypeToType (Scaled ExpSigmaType -> ExpSigmaType
forall a. Scaled a -> a
scaledThing Scaled ExpSigmaType
arg_ty)
                     ; TcSigmaType
res_tc_ty <- ExpSigmaType -> TcM TcSigmaType
expTypeToType ExpSigmaType
res_ty

                         -- another nested arrow is too much for now,
                         -- but I bet we'll never need this
                     ; MASSERT2( case arg_shape of
                                   SynFun {} -> False;
                                   _         -> True
                               , text "Too many nested arrows in SyntaxOpType" $$
                                 pprCtOrigin orig )

                     ; let arg_mult :: TcSigmaType
arg_mult = Scaled ExpSigmaType -> TcSigmaType
forall a. Scaled a -> TcSigmaType
scaledMult Scaled ExpSigmaType
arg_ty
                     ; CtOrigin
-> TcSigmaType
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType]
    -> [TcSigmaType]
    -> TcM ((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper))
-> TcM
     (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
      HsWrapper, [HsWrapper], HsWrapper)
forall a.
CtOrigin
-> TcSigmaType
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
tcSynArgA CtOrigin
orig TcSigmaType
arg_tc_ty [] SyntaxOpType
arg_shape (([TcSigmaType]
  -> [TcSigmaType]
  -> TcM ((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper))
 -> TcM
      (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
       HsWrapper, [HsWrapper], HsWrapper))
-> ([TcSigmaType]
    -> [TcSigmaType]
    -> TcM ((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper))
-> TcM
     (((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper),
      HsWrapper, [HsWrapper], HsWrapper)
forall a b. (a -> b) -> a -> b
$
                       \ [TcSigmaType]
arg_results [TcSigmaType]
arg_res_mults ->
                       CtOrigin
-> TcSigmaType
-> SyntaxOpType
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcM (a, TcSigmaType, TcSigmaType, TcSigmaType))
-> TcM ((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper)
forall a.
CtOrigin
-> TcSigmaType
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper)
tcSynArgE CtOrigin
orig TcSigmaType
res_tc_ty SyntaxOpType
res_shape (([TcSigmaType]
  -> [TcSigmaType] -> TcM (a, TcSigmaType, TcSigmaType, TcSigmaType))
 -> TcM ((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper))
-> ([TcSigmaType]
    -> [TcSigmaType] -> TcM (a, TcSigmaType, TcSigmaType, TcSigmaType))
-> TcM ((a, TcSigmaType, TcSigmaType, TcSigmaType), HsWrapper)
forall a b. (a -> b) -> a -> b
$
                       \ [TcSigmaType]
res_results [TcSigmaType]
res_res_mults ->
                       do { a
result <- [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside ([TcSigmaType]
arg_results [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
res_results) ([TcSigmaType
arg_mult] [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
arg_res_mults [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
res_res_mults)
                          ; (a, TcSigmaType, TcSigmaType, TcSigmaType)
-> TcM (a, TcSigmaType, TcSigmaType, TcSigmaType)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, TcSigmaType
arg_tc_ty, TcSigmaType
res_tc_ty, TcSigmaType
arg_mult) }}

           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return ( a
result
                    , HsWrapper
match_wrapper HsWrapper -> HsWrapper -> HsWrapper
<.>
                      HsWrapper
-> HsWrapper
-> Scaled TcSigmaType
-> TcSigmaType
-> SDoc
-> HsWrapper
mkWpFun (HsWrapper
arg_wrapper2 HsWrapper -> HsWrapper -> HsWrapper
<.> HsWrapper
arg_wrapper1) HsWrapper
res_wrapper
                              (TcSigmaType -> TcSigmaType -> Scaled TcSigmaType
forall a. TcSigmaType -> a -> Scaled a
Scaled TcSigmaType
op_mult TcSigmaType
arg_ty) TcSigmaType
res_ty SDoc
doc ) }
      where
        herald :: SDoc
herald = String -> SDoc
text String
"This rebindable syntax expects a function with"
        doc :: SDoc
doc = String -> SDoc
text String
"When checking a rebindable syntax operator arising from" SDoc -> SDoc -> SDoc
<+> CtOrigin -> SDoc
forall a. Outputable a => a -> SDoc
ppr CtOrigin
orig

    go TcSigmaType
rho_ty (SynType ExpSigmaType
the_ty)
      = do { HsWrapper
wrap   <- CtOrigin
-> UserTypeCtxt -> ExpSigmaType -> TcSigmaType -> TcM HsWrapper
tcSubTypePat CtOrigin
orig UserTypeCtxt
GenSigCtxt ExpSigmaType
the_ty TcSigmaType
rho_ty
           ; a
result <- [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside [] []
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
wrap) }

-- works on "actual" types, instantiating where necessary
-- See Note [tcSynArg]
tcSynArgA :: CtOrigin
          -> TcSigmaType
          -> [SyntaxOpType]              -- ^ argument shapes
          -> SyntaxOpType                -- ^ result shape
          -> ([TcSigmaType] -> [Mult] -> TcM a) -- ^ check the arguments
          -> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
            -- ^ returns a wrapper to be applied to the original function,
            -- wrappers to be applied to arguments
            -- and a wrapper to be applied to the overall expression
tcSynArgA :: CtOrigin
-> TcSigmaType
-> [SyntaxOpType]
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
tcSynArgA CtOrigin
orig TcSigmaType
sigma_ty [SyntaxOpType]
arg_shapes SyntaxOpType
res_shape [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside
  = do { (HsWrapper
match_wrapper, [Scaled TcSigmaType]
arg_tys, TcSigmaType
res_ty)
           <- SDoc
-> CtOrigin
-> Maybe SDoc
-> Int
-> TcSigmaType
-> TcM (HsWrapper, [Scaled TcSigmaType], TcSigmaType)
matchActualFunTysRho SDoc
herald CtOrigin
orig Maybe SDoc
forall a. Maybe a
Nothing
                                   ([SyntaxOpType] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [SyntaxOpType]
arg_shapes) TcSigmaType
sigma_ty
              -- match_wrapper :: sigma_ty "->" (arg_tys -> res_ty)
       ; ((a
result, HsWrapper
res_wrapper), [HsWrapper]
arg_wrappers)
           <- [TcSigmaType]
-> [SyntaxOpType]
-> ([TcSigmaType] -> [TcSigmaType] -> TcM (a, HsWrapper))
-> TcM ((a, HsWrapper), [HsWrapper])
forall a.
[TcSigmaType]
-> [SyntaxOpType]
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, [HsWrapper])
tc_syn_args_e ((Scaled TcSigmaType -> TcSigmaType)
-> [Scaled TcSigmaType] -> [TcSigmaType]
forall a b. (a -> b) -> [a] -> [b]
map Scaled TcSigmaType -> TcSigmaType
forall a. Scaled a -> a
scaledThing [Scaled TcSigmaType]
arg_tys) [SyntaxOpType]
arg_shapes (([TcSigmaType] -> [TcSigmaType] -> TcM (a, HsWrapper))
 -> TcM ((a, HsWrapper), [HsWrapper]))
-> ([TcSigmaType] -> [TcSigmaType] -> TcM (a, HsWrapper))
-> TcM ((a, HsWrapper), [HsWrapper])
forall a b. (a -> b) -> a -> b
$ \ [TcSigmaType]
arg_results [TcSigmaType]
arg_res_mults ->
              TcSigmaType
-> SyntaxOpType -> ([TcSigmaType] -> TcM a) -> TcM (a, HsWrapper)
forall a.
TcSigmaType
-> SyntaxOpType -> ([TcSigmaType] -> TcM a) -> TcM (a, HsWrapper)
tc_syn_arg    TcSigmaType
res_ty  SyntaxOpType
res_shape  (([TcSigmaType] -> TcM a) -> TcM (a, HsWrapper))
-> ([TcSigmaType] -> TcM a) -> TcM (a, HsWrapper)
forall a b. (a -> b) -> a -> b
$ \ [TcSigmaType]
res_results ->
              [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside ([TcSigmaType]
arg_results [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
res_results) ((Scaled TcSigmaType -> TcSigmaType)
-> [Scaled TcSigmaType] -> [TcSigmaType]
forall a b. (a -> b) -> [a] -> [b]
map Scaled TcSigmaType -> TcSigmaType
forall a. Scaled a -> TcSigmaType
scaledMult [Scaled TcSigmaType]
arg_tys [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
arg_res_mults)
       ; (a, HsWrapper, [HsWrapper], HsWrapper)
-> TcM (a, HsWrapper, [HsWrapper], HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
match_wrapper, [HsWrapper]
arg_wrappers, HsWrapper
res_wrapper) }
  where
    herald :: SDoc
herald = String -> SDoc
text String
"This rebindable syntax expects a function with"

    tc_syn_args_e :: [TcSigmaType] -> [SyntaxOpType]
                  -> ([TcSigmaType] -> [Mult] -> TcM a)
                  -> TcM (a, [HsWrapper])
                    -- the wrappers are for arguments
    tc_syn_args_e :: [TcSigmaType]
-> [SyntaxOpType]
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, [HsWrapper])
tc_syn_args_e (TcSigmaType
arg_ty : [TcSigmaType]
arg_tys) (SyntaxOpType
arg_shape : [SyntaxOpType]
arg_shapes) [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside
      = do { ((a
result, [HsWrapper]
arg_wraps), HsWrapper
arg_wrap)
               <- CtOrigin
-> TcSigmaType
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM (a, [HsWrapper]))
-> TcM ((a, [HsWrapper]), HsWrapper)
forall a.
CtOrigin
-> TcSigmaType
-> SyntaxOpType
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, HsWrapper)
tcSynArgE     CtOrigin
orig TcSigmaType
arg_ty  SyntaxOpType
arg_shape  (([TcSigmaType] -> [TcSigmaType] -> TcM (a, [HsWrapper]))
 -> TcM ((a, [HsWrapper]), HsWrapper))
-> ([TcSigmaType] -> [TcSigmaType] -> TcM (a, [HsWrapper]))
-> TcM ((a, [HsWrapper]), HsWrapper)
forall a b. (a -> b) -> a -> b
$ \ [TcSigmaType]
arg1_results [TcSigmaType]
arg1_mults ->
                  [TcSigmaType]
-> [SyntaxOpType]
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, [HsWrapper])
forall a.
[TcSigmaType]
-> [SyntaxOpType]
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, [HsWrapper])
tc_syn_args_e      [TcSigmaType]
arg_tys [SyntaxOpType]
arg_shapes (([TcSigmaType] -> [TcSigmaType] -> TcM a) -> TcM (a, [HsWrapper]))
-> ([TcSigmaType] -> [TcSigmaType] -> TcM a)
-> TcM (a, [HsWrapper])
forall a b. (a -> b) -> a -> b
$ \ [TcSigmaType]
args_results [TcSigmaType]
args_mults ->
                  [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside ([TcSigmaType]
arg1_results [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
args_results) ([TcSigmaType]
arg1_mults [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
args_mults)
           ; (a, [HsWrapper]) -> TcM (a, [HsWrapper])
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
arg_wrap HsWrapper -> [HsWrapper] -> [HsWrapper]
forall a. a -> [a] -> [a]
: [HsWrapper]
arg_wraps) }
    tc_syn_args_e [TcSigmaType]
_ [SyntaxOpType]
_ [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside = (, []) (a -> (a, [HsWrapper])) -> TcM a -> TcM (a, [HsWrapper])
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> [TcSigmaType] -> [TcSigmaType] -> TcM a
thing_inside [] []

    tc_syn_arg :: TcSigmaType -> SyntaxOpType
               -> ([TcSigmaType] -> TcM a)
               -> TcM (a, HsWrapper)
                  -- the wrapper applies to the overall result
    tc_syn_arg :: TcSigmaType
-> SyntaxOpType -> ([TcSigmaType] -> TcM a) -> TcM (a, HsWrapper)
tc_syn_arg TcSigmaType
res_ty SyntaxOpType
SynAny [TcSigmaType] -> TcM a
thing_inside
      = do { a
result <- [TcSigmaType] -> TcM a
thing_inside [TcSigmaType
res_ty]
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
idHsWrapper) }
    tc_syn_arg TcSigmaType
res_ty SyntaxOpType
SynRho [TcSigmaType] -> TcM a
thing_inside
      = do { (HsWrapper
inst_wrap, TcSigmaType
rho_ty) <- CtOrigin -> TcSigmaType -> TcM (HsWrapper, TcSigmaType)
topInstantiate CtOrigin
orig TcSigmaType
res_ty
               -- inst_wrap :: res_ty "->" rho_ty
           ; a
result <- [TcSigmaType] -> TcM a
thing_inside [TcSigmaType
rho_ty]
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
inst_wrap) }
    tc_syn_arg TcSigmaType
res_ty SyntaxOpType
SynList [TcSigmaType] -> TcM a
thing_inside
      = do { (HsWrapper
inst_wrap, TcSigmaType
rho_ty) <- CtOrigin -> TcSigmaType -> TcM (HsWrapper, TcSigmaType)
topInstantiate CtOrigin
orig TcSigmaType
res_ty
               -- inst_wrap :: res_ty "->" rho_ty
           ; (TcCoercionR
list_co, TcSigmaType
elt_ty)   <- TcSigmaType -> TcM (TcCoercionR, TcSigmaType)
matchExpectedListTy TcSigmaType
rho_ty
               -- list_co :: [elt_ty] ~N rho_ty
           ; a
result <- [TcSigmaType] -> TcM a
thing_inside [TcSigmaType
elt_ty]
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, TcCoercionR -> HsWrapper
mkWpCastN (TcCoercionR -> TcCoercionR
mkTcSymCo TcCoercionR
list_co) HsWrapper -> HsWrapper -> HsWrapper
<.> HsWrapper
inst_wrap) }
    tc_syn_arg TcSigmaType
_ (SynFun {}) [TcSigmaType] -> TcM a
_
      = String -> SDoc -> TcM (a, HsWrapper)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"tcSynArgA hits a SynFun" (CtOrigin -> SDoc
forall a. Outputable a => a -> SDoc
ppr CtOrigin
orig)
    tc_syn_arg TcSigmaType
res_ty (SynType ExpSigmaType
the_ty) [TcSigmaType] -> TcM a
thing_inside
      = do { HsWrapper
wrap   <- CtOrigin
-> UserTypeCtxt -> TcSigmaType -> ExpSigmaType -> TcM HsWrapper
tcSubType CtOrigin
orig UserTypeCtxt
GenSigCtxt TcSigmaType
res_ty ExpSigmaType
the_ty
           ; a
result <- [TcSigmaType] -> TcM a
thing_inside []
           ; (a, HsWrapper) -> TcM (a, HsWrapper)
forall (m :: * -> *) a. Monad m => a -> m a
return (a
result, HsWrapper
wrap) }

{-
Note [Push result type in]
~~~~~~~~~~~~~~~~~~~~~~~~~~
Unify with expected result before type-checking the args so that the
info from res_ty percolates to args.  This is when we might detect a
too-few args situation.  (One can think of cases when the opposite
order would give a better error message.)
experimenting with putting this first.

Here's an example where it actually makes a real difference

   class C t a b | t a -> b
   instance C Char a Bool

   data P t a = forall b. (C t a b) => MkP b
   data Q t   = MkQ (forall a. P t a)

   f1, f2 :: Q Char;
   f1 = MkQ (MkP True)
   f2 = MkQ (MkP True :: forall a. P Char a)

With the change, f1 will type-check, because the 'Char' info from
the signature is propagated into MkQ's argument. With the check
in the other order, the extra signature in f2 is reqd.
-}

{- *********************************************************************
*                                                                      *
                 Record bindings
*                                                                      *
********************************************************************* -}

getFixedTyVars :: [FieldLabelString] -> [TyVar] -> [ConLike] -> TyVarSet
-- These tyvars must not change across the updates
getFixedTyVars :: [FastString] -> [Id] -> [ConLike] -> VarSet
getFixedTyVars [FastString]
upd_fld_occs [Id]
univ_tvs [ConLike]
cons
      = [Id] -> VarSet
mkVarSet [Id
tv1 | ConLike
con <- [ConLike]
cons
                      , let ([Id]
u_tvs, [Id]
_, [EqSpec]
eqspec, [TcSigmaType]
prov_theta
                             , [TcSigmaType]
req_theta, [Scaled TcSigmaType]
arg_tys, TcSigmaType
_)
                              = ConLike
-> ([Id], [Id], [EqSpec], [TcSigmaType], [TcSigmaType],
    [Scaled TcSigmaType], TcSigmaType)
conLikeFullSig ConLike
con
                            theta :: [TcSigmaType]
theta = [EqSpec] -> [TcSigmaType]
eqSpecPreds [EqSpec]
eqspec
                                     [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
prov_theta
                                     [TcSigmaType] -> [TcSigmaType] -> [TcSigmaType]
forall a. [a] -> [a] -> [a]
++ [TcSigmaType]
req_theta
                            flds :: [FieldLbl Name]
flds = ConLike -> [FieldLbl Name]
conLikeFieldLabels ConLike
con
                            fixed_tvs :: VarSet
fixed_tvs = [TcSigmaType] -> VarSet
exactTyCoVarsOfTypes ((Scaled TcSigmaType -> TcSigmaType)
-> [Scaled TcSigmaType] -> [TcSigmaType]
forall a b. (a -> b) -> [a] -> [b]
map Scaled TcSigmaType -> TcSigmaType
forall a. Scaled a -> a
scaledThing [Scaled TcSigmaType]
fixed_tys)
                                    -- fixed_tys: See Note [Type of a record update]
                                        VarSet -> VarSet -> VarSet
`unionVarSet` [TcSigmaType] -> VarSet
tyCoVarsOfTypes [TcSigmaType]
theta
                                    -- Universally-quantified tyvars that
                                    -- appear in any of the *implicit*
                                    -- arguments to the constructor are fixed
                                    -- See Note [Implicit type sharing]

                            fixed_tys :: [Scaled TcSigmaType]
fixed_tys = [Scaled TcSigmaType
ty | (FieldLbl Name
fl, Scaled TcSigmaType
ty) <- [FieldLbl Name]
-> [Scaled TcSigmaType] -> [(FieldLbl Name, Scaled TcSigmaType)]
forall a b. [a] -> [b] -> [(a, b)]
zip [FieldLbl Name]
flds [Scaled TcSigmaType]
arg_tys
                                            , Bool -> Bool
not (FieldLbl Name -> FastString
forall a. FieldLbl a -> FastString
flLabel FieldLbl Name
fl FastString -> [FastString] -> Bool
forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
`elem` [FastString]
upd_fld_occs)]
                      , (Id
tv1,Id
tv) <- [Id]
univ_tvs [Id] -> [Id] -> [(Id, Id)]
forall a b. [a] -> [b] -> [(a, b)]
`zip` [Id]
u_tvs
                      , Id
tv Id -> VarSet -> Bool
`elemVarSet` VarSet
fixed_tvs ]


-- Disambiguate the fields in a record update.
-- See Note [Disambiguating record fields] in GHC.Tc.Gen.Head
disambiguateRecordBinds :: LHsExpr GhcRn -> TcRhoType
                 -> [LHsRecUpdField GhcRn] -> ExpRhoType
                 -> TcM [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
disambiguateRecordBinds :: LHsExpr GhcRn
-> TcSigmaType
-> [LHsRecUpdField GhcRn]
-> ExpSigmaType
-> TcM [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
disambiguateRecordBinds LHsExpr GhcRn
record_expr TcSigmaType
record_rho [LHsRecUpdField GhcRn]
rbnds ExpSigmaType
res_ty
    -- Are all the fields unambiguous?
  = case (Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> Maybe
      (Located
         (HsRecField'
            (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
       Name))
-> [Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> Maybe
     [(Located
         (HsRecField'
            (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
       Name)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> Maybe
     (Located
        (HsRecField'
           (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
      Name)
LHsRecUpdField GhcRn -> Maybe (LHsRecUpdField GhcRn, Name)
isUnambiguous [Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecUpdField GhcRn]
rbnds of
                     -- If so, just skip to looking up the Ids
                     -- Always the case if DuplicateRecordFields is off
      Just [(Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  Name)]
rbnds' -> ((Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  Name)
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (GenLocated
         SrcSpan
         (HsRecField'
            (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))))
-> [(Located
       (HsRecField'
          (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
     Name)]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
 Name)
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))))
(LHsRecUpdField GhcRn, Name)
-> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
lookupSelector [(Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  Name)]
rbnds'
      Maybe
  [(Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
    Name)]
Nothing     -> -- If not, try to identify a single parent
        do { FamInstEnvs
fam_inst_envs <- TcM FamInstEnvs
tcGetFamInstEnvs
             -- Look up the possible parents for each field
           ; [(Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  [(RecSelParent, GlobalRdrElt)])]
rbnds_with_parents <- IOEnv
  (Env TcGblEnv TcLclEnv)
  [(Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
    [(RecSelParent, GlobalRdrElt)])]
TcM [(LHsRecUpdField GhcRn, [(RecSelParent, GlobalRdrElt)])]
getUpdFieldsParents
           ; let possible_parents :: [[RecSelParent]]
possible_parents = ((Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  [(RecSelParent, GlobalRdrElt)])
 -> [RecSelParent])
-> [(Located
       (HsRecField'
          (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
     [(RecSelParent, GlobalRdrElt)])]
-> [[RecSelParent]]
forall a b. (a -> b) -> [a] -> [b]
map (((RecSelParent, GlobalRdrElt) -> RecSelParent)
-> [(RecSelParent, GlobalRdrElt)] -> [RecSelParent]
forall a b. (a -> b) -> [a] -> [b]
map (RecSelParent, GlobalRdrElt) -> RecSelParent
forall a b. (a, b) -> a
fst ([(RecSelParent, GlobalRdrElt)] -> [RecSelParent])
-> ((Located
       (HsRecField'
          (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
     [(RecSelParent, GlobalRdrElt)])
    -> [(RecSelParent, GlobalRdrElt)])
-> (Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
    [(RecSelParent, GlobalRdrElt)])
-> [RecSelParent]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
 [(RecSelParent, GlobalRdrElt)])
-> [(RecSelParent, GlobalRdrElt)]
forall a b. (a, b) -> b
snd) [(Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  [(RecSelParent, GlobalRdrElt)])]
rbnds_with_parents
             -- Identify a single parent
           ; RecSelParent
p <- FamInstEnvs -> [[RecSelParent]] -> TcM RecSelParent
identifyParent FamInstEnvs
fam_inst_envs [[RecSelParent]]
possible_parents
             -- Pick the right selector with that parent for each field
           ; IOEnv
  (Env TcGblEnv TcLclEnv)
  [GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
forall r. TcM r -> TcM r
checkNoErrs (IOEnv
   (Env TcGblEnv TcLclEnv)
   [GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      [GenLocated
         SrcSpan
         (HsRecField'
            (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))])
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
forall a b. (a -> b) -> a -> b
$ ((Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  [(RecSelParent, GlobalRdrElt)])
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (GenLocated
         SrcSpan
         (HsRecField'
            (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))))
-> [(Located
       (HsRecField'
          (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
     [(RecSelParent, GlobalRdrElt)])]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (RecSelParent
-> (LHsRecUpdField GhcRn, [(RecSelParent, GlobalRdrElt)])
-> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
pickParent RecSelParent
p) [(Located
    (HsRecField'
       (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
  [(RecSelParent, GlobalRdrElt)])]
rbnds_with_parents }
  where
    -- Extract the selector name of a field update if it is unambiguous
    isUnambiguous :: LHsRecUpdField GhcRn -> Maybe (LHsRecUpdField GhcRn,Name)
    isUnambiguous :: LHsRecUpdField GhcRn -> Maybe (LHsRecUpdField GhcRn, Name)
isUnambiguous LHsRecUpdField GhcRn
x = case GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)
-> AmbiguousFieldOcc GhcRn
forall l e. GenLocated l e -> e
unLoc (HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)
forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl (Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
LHsRecUpdField GhcRn
x)) of
                        Unambiguous XUnambiguous GhcRn
sel_name Located RdrName
_ -> (Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
 Name)
-> Maybe
     (Located
        (HsRecField'
           (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
      Name)
forall a. a -> Maybe a
Just (Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
LHsRecUpdField GhcRn
x, Name
XUnambiguous GhcRn
sel_name)
                        Ambiguous{}            -> Maybe (LHsRecUpdField GhcRn, Name)
forall a. Maybe a
Nothing

    -- Look up the possible parents and selector GREs for each field
    getUpdFieldsParents :: TcM [(LHsRecUpdField GhcRn
                                , [(RecSelParent, GlobalRdrElt)])]
    getUpdFieldsParents :: TcM [(LHsRecUpdField GhcRn, [(RecSelParent, GlobalRdrElt)])]
getUpdFieldsParents
      = ([[(RecSelParent, GlobalRdrElt)]]
 -> [(Located
        (HsRecField'
           (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
      [(RecSelParent, GlobalRdrElt)])])
-> IOEnv (Env TcGblEnv TcLclEnv) [[(RecSelParent, GlobalRdrElt)]]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(Located
         (HsRecField'
            (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
       [(RecSelParent, GlobalRdrElt)])]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap ([Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> [[(RecSelParent, GlobalRdrElt)]]
-> [(Located
       (HsRecField'
          (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
     [(RecSelParent, GlobalRdrElt)])]
forall a b. [a] -> [b] -> [(a, b)]
zip [Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecUpdField GhcRn]
rbnds) (IOEnv (Env TcGblEnv TcLclEnv) [[(RecSelParent, GlobalRdrElt)]]
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      [(Located
          (HsRecField'
             (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
        [(RecSelParent, GlobalRdrElt)])])
-> IOEnv (Env TcGblEnv TcLclEnv) [[(RecSelParent, GlobalRdrElt)]]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [(Located
         (HsRecField'
            (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))),
       [(RecSelParent, GlobalRdrElt)])]
forall a b. (a -> b) -> a -> b
$ (Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> IOEnv (Env TcGblEnv TcLclEnv) [(RecSelParent, GlobalRdrElt)])
-> [Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> IOEnv (Env TcGblEnv TcLclEnv) [[(RecSelParent, GlobalRdrElt)]]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM
          (RdrName
-> IOEnv (Env TcGblEnv TcLclEnv) [(RecSelParent, GlobalRdrElt)]
lookupParents (RdrName
 -> IOEnv (Env TcGblEnv TcLclEnv) [(RecSelParent, GlobalRdrElt)])
-> (Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> RdrName)
-> Located
     (HsRecField'
        (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> IOEnv (Env TcGblEnv TcLclEnv) [(RecSelParent, GlobalRdrElt)]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Located RdrName -> RdrName
forall l e. GenLocated l e -> e
unLoc (Located RdrName -> RdrName)
-> (Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> Located RdrName)
-> Located
     (HsRecField'
        (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> RdrName
forall b c a. (b -> c) -> (a -> b) -> a -> c
. HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
-> Located RdrName
forall (p :: Pass). HsRecUpdField (GhcPass p) -> Located RdrName
hsRecUpdFieldRdr (HsRecField'
   (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
 -> Located RdrName)
-> (Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> Located
     (HsRecField'
        (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> Located RdrName
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc)
          [Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecUpdField GhcRn]
rbnds

    -- Given a the lists of possible parents for each field,
    -- identify a single parent
    identifyParent :: FamInstEnvs -> [[RecSelParent]] -> TcM RecSelParent
    identifyParent :: FamInstEnvs -> [[RecSelParent]] -> TcM RecSelParent
identifyParent FamInstEnvs
fam_inst_envs [[RecSelParent]]
possible_parents
      = case ([RecSelParent] -> [RecSelParent] -> [RecSelParent])
-> [[RecSelParent]] -> [RecSelParent]
forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
foldr1 [RecSelParent] -> [RecSelParent] -> [RecSelParent]
forall a. Eq a => [a] -> [a] -> [a]
intersect [[RecSelParent]]
possible_parents of
        -- No parents for all fields: record update is ill-typed
        []  -> SDoc -> TcM RecSelParent
forall a. SDoc -> TcM a
failWithTc ([LHsRecUpdField GhcRn] -> SDoc
noPossibleParents [LHsRecUpdField GhcRn]
rbnds)

        -- Exactly one datatype with all the fields: use that
        [RecSelParent
p] -> RecSelParent -> TcM RecSelParent
forall (m :: * -> *) a. Monad m => a -> m a
return RecSelParent
p

        -- Multiple possible parents: try harder to disambiguate
        -- Can we get a parent TyCon from the pushed-in type?
        RecSelParent
_:[RecSelParent]
_ | Just TyCon
p <- FamInstEnvs -> ExpSigmaType -> Maybe TyCon
tyConOfET FamInstEnvs
fam_inst_envs ExpSigmaType
res_ty -> RecSelParent -> TcM RecSelParent
forall (m :: * -> *) a. Monad m => a -> m a
return (TyCon -> RecSelParent
RecSelData TyCon
p)

        -- Does the expression being updated have a type signature?
        -- If so, try to extract a parent TyCon from it
            | Just {} <- HsExpr GhcRn -> Maybe (LHsSigWcType GhcRn)
obviousSig (GenLocated SrcSpan (HsExpr GhcRn) -> HsExpr GhcRn
forall l e. GenLocated l e -> e
unLoc GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
record_expr)
            , Just TyCon
tc <- FamInstEnvs -> TcSigmaType -> Maybe TyCon
tyConOf FamInstEnvs
fam_inst_envs TcSigmaType
record_rho
            -> RecSelParent -> TcM RecSelParent
forall (m :: * -> *) a. Monad m => a -> m a
return (TyCon -> RecSelParent
RecSelData TyCon
tc)

        -- Nothing else we can try...
        [RecSelParent]
_ -> SDoc -> TcM RecSelParent
forall a. SDoc -> TcM a
failWithTc SDoc
badOverloadedUpdate

    -- Make a field unambiguous by choosing the given parent.
    -- Emits an error if the field cannot have that parent,
    -- e.g. if the user writes
    --     r { x = e } :: T
    -- where T does not have field x.
    pickParent :: RecSelParent
               -> (LHsRecUpdField GhcRn, [(RecSelParent, GlobalRdrElt)])
               -> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
    pickParent :: RecSelParent
-> (LHsRecUpdField GhcRn, [(RecSelParent, GlobalRdrElt)])
-> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
pickParent RecSelParent
p (LHsRecUpdField GhcRn
upd, [(RecSelParent, GlobalRdrElt)]
xs)
      = case RecSelParent
-> [(RecSelParent, GlobalRdrElt)] -> Maybe GlobalRdrElt
forall a b. Eq a => a -> [(a, b)] -> Maybe b
lookup RecSelParent
p [(RecSelParent, GlobalRdrElt)]
xs of
                      -- Phew! The parent is valid for this field.
                      -- Previously ambiguous fields must be marked as
                      -- used now that we know which one is meant, but
                      -- unambiguous ones shouldn't be recorded again
                      -- (giving duplicate deprecation warnings).
          Just GlobalRdrElt
gre -> do { Bool -> TcRn () -> TcRn ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless ([(RecSelParent, GlobalRdrElt)] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null ([(RecSelParent, GlobalRdrElt)] -> [(RecSelParent, GlobalRdrElt)]
forall a. [a] -> [a]
tail [(RecSelParent, GlobalRdrElt)]
xs)) (TcRn () -> TcRn ()) -> TcRn () -> TcRn ()
forall a b. (a -> b) -> a -> b
$ do
                             let L SrcSpan
loc AmbiguousFieldOcc GhcRn
_ = HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)
forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl (Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
LHsRecUpdField GhcRn
upd)
                             SrcSpan -> TcRn () -> TcRn ()
forall a. SrcSpan -> TcRn a -> TcRn a
setSrcSpan SrcSpan
loc (TcRn () -> TcRn ()) -> TcRn () -> TcRn ()
forall a b. (a -> b) -> a -> b
$ Bool -> GlobalRdrElt -> TcRn ()
addUsedGRE Bool
True GlobalRdrElt
gre
                         ; (LHsRecUpdField GhcRn, Name)
-> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
lookupSelector (LHsRecUpdField GhcRn
upd, GlobalRdrElt -> Name
gre_name GlobalRdrElt
gre) }
                      -- The field doesn't belong to this parent, so report
                      -- an error but keep going through all the fields
          Maybe GlobalRdrElt
Nothing  -> do { SDoc -> TcRn ()
addErrTc (RecSelParent -> RdrName -> SDoc
fieldNotInType RecSelParent
p
                                      (Located RdrName -> RdrName
forall l e. GenLocated l e -> e
unLoc (HsRecUpdField GhcRn -> Located RdrName
forall (p :: Pass). HsRecUpdField (GhcPass p) -> Located RdrName
hsRecUpdFieldRdr (Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
LHsRecUpdField GhcRn
upd))))
                         ; (LHsRecUpdField GhcRn, Name)
-> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
lookupSelector (LHsRecUpdField GhcRn
upd, GlobalRdrElt -> Name
gre_name ((RecSelParent, GlobalRdrElt) -> GlobalRdrElt
forall a b. (a, b) -> b
snd ([(RecSelParent, GlobalRdrElt)] -> (RecSelParent, GlobalRdrElt)
forall a. [a] -> a
head [(RecSelParent, GlobalRdrElt)]
xs))) }

    -- Given a (field update, selector name) pair, look up the
    -- selector to give a field update with an unambiguous Id
    lookupSelector :: (LHsRecUpdField GhcRn, Name)
                 -> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
    lookupSelector :: (LHsRecUpdField GhcRn, Name)
-> TcM (LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn))
lookupSelector (L SrcSpan
l HsRecUpdField GhcRn
upd, Name
n)
      = do { Id
i <- Name -> TcM Id
tcLookupId Name
n
           ; let L SrcSpan
loc AmbiguousFieldOcc GhcRn
af = HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)
forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
HsRecUpdField GhcRn
upd
                 lbl :: RdrName
lbl      = AmbiguousFieldOcc GhcRn -> RdrName
forall (p :: Pass). AmbiguousFieldOcc (GhcPass p) -> RdrName
rdrNameAmbiguousFieldOcc AmbiguousFieldOcc GhcRn
af
           ; GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))))
forall (m :: * -> *) a. Monad m => a -> m a
return (GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (GenLocated
         SrcSpan
         (HsRecField'
            (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))))
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (GenLocated
        SrcSpan
        (HsRecField'
           (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))))
forall a b. (a -> b) -> a -> b
$ SrcSpan
-> HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
forall l e. l -> e -> GenLocated l e
L SrcSpan
l HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
HsRecUpdField GhcRn
upd { hsRecFieldLbl :: GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
hsRecFieldLbl
                                  = SrcSpan
-> AmbiguousFieldOcc GhcTc
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XUnambiguous GhcTc -> Located RdrName -> AmbiguousFieldOcc GhcTc
forall pass.
XUnambiguous pass -> Located RdrName -> AmbiguousFieldOcc pass
Unambiguous Id
XUnambiguous GhcTc
i (SrcSpan -> RdrName -> Located RdrName
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc RdrName
lbl)) } }


{-
Game plan for record bindings
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1. Find the TyCon for the bindings, from the first field label.

2. Instantiate its tyvars and unify (T a1 .. an) with expected_ty.

For each binding field = value

3. Instantiate the field type (from the field label) using the type
   envt from step 2.

4  Type check the value using tcValArg, passing the field type as
   the expected argument type.

This extends OK when the field types are universally quantified.
-}

tcRecordBinds
        :: ConLike
        -> [TcType]     -- Expected type for each field
        -> HsRecordBinds GhcRn
        -> TcM (HsRecordBinds GhcTc)

tcRecordBinds :: ConLike
-> [TcSigmaType]
-> HsRecordBinds GhcRn
-> TcM (HsRecordBinds GhcTc)
tcRecordBinds ConLike
con_like [TcSigmaType]
arg_tys (HsRecFields [LHsRecField GhcRn (LHsExpr GhcRn)]
rbinds Maybe (Located Int)
dd)
  = do  { [Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))]
mb_binds <- (LHsRecField GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))))
-> [LHsRecField GhcRn (GenLocated SrcSpan (HsExpr GhcRn))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM LHsRecField GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc))))
LHsRecField GhcRn (LHsExpr GhcRn)
-> TcM (Maybe (LHsRecField GhcTc (LHsExpr GhcTc)))
do_bind [LHsRecField GhcRn (GenLocated SrcSpan (HsExpr GhcRn))]
[LHsRecField GhcRn (LHsExpr GhcRn)]
rbinds
        ; HsRecFields GhcTc (Located (HsExpr GhcTc))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (HsRecFields GhcTc (Located (HsExpr GhcTc)))
forall (m :: * -> *) a. Monad m => a -> m a
return ([LHsRecField GhcTc (Located (HsExpr GhcTc))]
-> Maybe (Located Int)
-> HsRecFields GhcTc (Located (HsExpr GhcTc))
forall p arg.
[LHsRecField p arg] -> Maybe (Located Int) -> HsRecFields p arg
HsRecFields ([Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))]
-> [LHsRecField GhcTc (Located (HsExpr GhcTc))]
forall a. [Maybe a] -> [a]
catMaybes [Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))]
mb_binds) Maybe (Located Int)
dd) }
  where
    fields :: [Name]
fields = (FieldLbl Name -> Name) -> [FieldLbl Name] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map FieldLbl Name -> Name
forall a. FieldLbl a -> a
flSelector ([FieldLbl Name] -> [Name]) -> [FieldLbl Name] -> [Name]
forall a b. (a -> b) -> a -> b
$ ConLike -> [FieldLbl Name]
conLikeFieldLabels ConLike
con_like
    flds_w_tys :: [(Name, TcSigmaType)]
flds_w_tys = String -> [Name] -> [TcSigmaType] -> [(Name, TcSigmaType)]
forall a b. String -> [a] -> [b] -> [(a, b)]
zipEqual String
"tcRecordBinds" [Name]
fields [TcSigmaType]
arg_tys

    do_bind :: LHsRecField GhcRn (LHsExpr GhcRn)
            -> TcM (Maybe (LHsRecField GhcTc (LHsExpr GhcTc)))
    do_bind :: LHsRecField GhcRn (LHsExpr GhcRn)
-> TcM (Maybe (LHsRecField GhcTc (LHsExpr GhcTc)))
do_bind (L SrcSpan
l fld :: HsRecField GhcRn (LHsExpr GhcRn)
fld@(HsRecField { hsRecFieldLbl :: forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl = Located (FieldOcc GhcRn)
f
                                 , hsRecFieldArg :: forall id arg. HsRecField' id arg -> arg
hsRecFieldArg = LHsExpr GhcRn
rhs }))

      = do { Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
mb <- ConLike
-> [(Name, TcSigmaType)]
-> LFieldOcc GhcRn
-> LHsExpr GhcRn
-> TcM (Maybe (LFieldOcc GhcTc, LHsExpr GhcTc))
tcRecordField ConLike
con_like [(Name, TcSigmaType)]
flds_w_tys Located (FieldOcc GhcRn)
LFieldOcc GhcRn
f LHsExpr GhcRn
rhs
           ; case Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
mb of
               Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
Nothing         -> Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc))))
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))
forall a. Maybe a
Nothing
               Just (Located (FieldOcc GhcTc)
f', Located (HsExpr GhcTc)
rhs') -> Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc))))
forall (m :: * -> *) a. Monad m => a -> m a
return (LHsRecField GhcTc (Located (HsExpr GhcTc))
-> Maybe (LHsRecField GhcTc (Located (HsExpr GhcTc)))
forall a. a -> Maybe a
Just (SrcSpan
-> HsRecField' (FieldOcc GhcTc) (Located (HsExpr GhcTc))
-> LHsRecField GhcTc (Located (HsExpr GhcTc))
forall l e. l -> e -> GenLocated l e
L SrcSpan
l (HsRecField' (FieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
HsRecField GhcRn (LHsExpr GhcRn)
fld { hsRecFieldLbl :: Located (FieldOcc GhcTc)
hsRecFieldLbl = Located (FieldOcc GhcTc)
f'
                                                          , hsRecFieldArg :: Located (HsExpr GhcTc)
hsRecFieldArg = Located (HsExpr GhcTc)
rhs' }))) }

tcRecordUpd
        :: ConLike
        -> [TcType]     -- Expected type for each field
        -> [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
        -> TcM [LHsRecUpdField GhcTc]

tcRecordUpd :: ConLike
-> [TcSigmaType]
-> [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
-> TcM [LHsRecUpdField GhcTc]
tcRecordUpd ConLike
con_like [TcSigmaType]
arg_tys [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
rbinds = ([Maybe
    (Located
       (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))]
 -> [Located
       (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))])
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Maybe
        (Located
           (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Located
        (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap [Maybe
   (Located
      (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))]
-> [Located
      (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))]
forall a. [Maybe a] -> [a]
catMaybes (IOEnv
   (Env TcGblEnv TcLclEnv)
   [Maybe
      (Located
         (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))]
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      [Located
         (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))])
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Maybe
        (Located
           (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Located
        (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))]
forall a b. (a -> b) -> a -> b
$ (GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (Maybe
         (Located
            (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))))
-> [GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     [Maybe
        (Located
           (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe
        (Located
           (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))))
LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)
-> TcM (Maybe (LHsRecUpdField GhcTc))
do_bind [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
rbinds
  where
    fields :: [Name]
fields = (FieldLbl Name -> Name) -> [FieldLbl Name] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map FieldLbl Name -> Name
forall a. FieldLbl a -> a
flSelector ([FieldLbl Name] -> [Name]) -> [FieldLbl Name] -> [Name]
forall a b. (a -> b) -> a -> b
$ ConLike -> [FieldLbl Name]
conLikeFieldLabels ConLike
con_like
    flds_w_tys :: [(Name, TcSigmaType)]
flds_w_tys = String -> [Name] -> [TcSigmaType] -> [(Name, TcSigmaType)]
forall a b. String -> [a] -> [b] -> [(a, b)]
zipEqual String
"tcRecordUpd" [Name]
fields [TcSigmaType]
arg_tys

    do_bind :: LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)
            -> TcM (Maybe (LHsRecUpdField GhcTc))
    do_bind :: LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)
-> TcM (Maybe (LHsRecUpdField GhcTc))
do_bind (L SrcSpan
l fld :: HsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)
fld@(HsRecField { hsRecFieldLbl :: forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl = L SrcSpan
loc AmbiguousFieldOcc GhcTc
af
                                 , hsRecFieldArg :: forall id arg. HsRecField' id arg -> arg
hsRecFieldArg = LHsExpr GhcRn
rhs }))
      = do { let lbl :: RdrName
lbl = AmbiguousFieldOcc GhcTc -> RdrName
forall (p :: Pass). AmbiguousFieldOcc (GhcPass p) -> RdrName
rdrNameAmbiguousFieldOcc AmbiguousFieldOcc GhcTc
af
                 sel_id :: Id
sel_id = AmbiguousFieldOcc GhcTc -> Id
selectorAmbiguousFieldOcc AmbiguousFieldOcc GhcTc
af
                 f :: Located (FieldOcc GhcRn)
f = SrcSpan -> FieldOcc GhcRn -> Located (FieldOcc GhcRn)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XCFieldOcc GhcRn -> Located RdrName -> FieldOcc GhcRn
forall pass. XCFieldOcc pass -> Located RdrName -> FieldOcc pass
FieldOcc (Id -> Name
idName Id
sel_id) (SrcSpan -> RdrName -> Located RdrName
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc RdrName
lbl))
           ; Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
mb <- ConLike
-> [(Name, TcSigmaType)]
-> LFieldOcc GhcRn
-> LHsExpr GhcRn
-> TcM (Maybe (LFieldOcc GhcTc, LHsExpr GhcTc))
tcRecordField ConLike
con_like [(Name, TcSigmaType)]
flds_w_tys Located (FieldOcc GhcRn)
LFieldOcc GhcRn
f LHsExpr GhcRn
rhs
           ; case Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
mb of
               Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
Nothing         -> Maybe
  (Located
     (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe
        (Located
           (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))))
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe
  (Located
     (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))
forall a. Maybe a
Nothing
               Just (Located (FieldOcc GhcTc)
f', Located (HsExpr GhcTc)
rhs') ->
                 Maybe
  (Located
     (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe
        (Located
           (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))))
forall (m :: * -> *) a. Monad m => a -> m a
return (Located
  (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))
-> Maybe
     (Located
        (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))))
forall a. a -> Maybe a
Just
                         (SrcSpan
-> HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc))
-> Located
     (HsRecField' (AmbiguousFieldOcc GhcTc) (Located (HsExpr GhcTc)))
forall l e. l -> e -> GenLocated l e
L SrcSpan
l (HsRecField'
  (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
HsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)
fld { hsRecFieldLbl :: GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
hsRecFieldLbl
                                      = SrcSpan
-> AmbiguousFieldOcc GhcTc
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XUnambiguous GhcTc -> Located RdrName -> AmbiguousFieldOcc GhcTc
forall pass.
XUnambiguous pass -> Located RdrName -> AmbiguousFieldOcc pass
Unambiguous
                                               (FieldOcc GhcTc -> XCFieldOcc GhcTc
forall pass. FieldOcc pass -> XCFieldOcc pass
extFieldOcc (Located (FieldOcc GhcTc) -> FieldOcc GhcTc
forall l e. GenLocated l e -> e
unLoc Located (FieldOcc GhcTc)
f'))
                                               (SrcSpan -> RdrName -> Located RdrName
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc RdrName
lbl))
                                   , hsRecFieldArg :: Located (HsExpr GhcTc)
hsRecFieldArg = Located (HsExpr GhcTc)
rhs' }))) }

tcRecordField :: ConLike -> Assoc Name Type
              -> LFieldOcc GhcRn -> LHsExpr GhcRn
              -> TcM (Maybe (LFieldOcc GhcTc, LHsExpr GhcTc))
tcRecordField :: ConLike
-> [(Name, TcSigmaType)]
-> LFieldOcc GhcRn
-> LHsExpr GhcRn
-> TcM (Maybe (LFieldOcc GhcTc, LHsExpr GhcTc))
tcRecordField ConLike
con_like [(Name, TcSigmaType)]
flds_w_tys (L loc (FieldOcc sel_name lbl)) LHsExpr GhcRn
rhs
  | Just TcSigmaType
field_ty <- [(Name, TcSigmaType)] -> Name -> Maybe TcSigmaType
forall a b. Eq a => Assoc a b -> a -> Maybe b
assocMaybe [(Name, TcSigmaType)]
flds_w_tys Name
XCFieldOcc GhcRn
sel_name
      = SDoc
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
forall a. SDoc -> TcM a -> TcM a
addErrCtxt (FastString -> SDoc
fieldCtxt FastString
field_lbl) (IOEnv
   (Env TcGblEnv TcLclEnv)
   (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
 -> IOEnv
      (Env TcGblEnv TcLclEnv)
      (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
forall a b. (a -> b) -> a -> b
$
        do { Located (HsExpr GhcTc)
rhs' <- LHsExpr GhcRn -> TcSigmaType -> TcM (LHsExpr GhcTc)
tcCheckPolyExprNC LHsExpr GhcRn
rhs TcSigmaType
field_ty
           ; let field_id :: Id
field_id = OccName -> Unique -> TcSigmaType -> TcSigmaType -> SrcSpan -> Id
mkUserLocal (Name -> OccName
nameOccName Name
XCFieldOcc GhcRn
sel_name)
                                        (Name -> Unique
nameUnique Name
XCFieldOcc GhcRn
sel_name)
                                        TcSigmaType
Many TcSigmaType
field_ty SrcSpan
loc
                -- Yuk: the field_id has the *unique* of the selector Id
                --          (so we can find it easily)
                --      but is a LocalId with the appropriate type of the RHS
                --          (so the desugarer knows the type of local binder to make)
           ; Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
forall (m :: * -> *) a. Monad m => a -> m a
return ((Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
-> Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
forall a. a -> Maybe a
Just (SrcSpan -> FieldOcc GhcTc -> Located (FieldOcc GhcTc)
forall l e. l -> e -> GenLocated l e
L SrcSpan
loc (XCFieldOcc GhcTc -> Located RdrName -> FieldOcc GhcTc
forall pass. XCFieldOcc pass -> Located RdrName -> FieldOcc pass
FieldOcc Id
XCFieldOcc GhcTc
field_id Located RdrName
lbl), Located (HsExpr GhcTc)
rhs')) }
      | Bool
otherwise
      = do { SDoc -> TcRn ()
addErrTc (ConLike -> FastString -> SDoc
badFieldCon ConLike
con_like FastString
field_lbl)
           ; Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
-> IOEnv
     (Env TcGblEnv TcLclEnv)
     (Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc)))
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe (Located (FieldOcc GhcTc), Located (HsExpr GhcTc))
forall a. Maybe a
Nothing }
  where
        field_lbl :: FastString
field_lbl = OccName -> FastString
occNameFS (OccName -> FastString) -> OccName -> FastString
forall a b. (a -> b) -> a -> b
$ RdrName -> OccName
rdrNameOcc (Located RdrName -> RdrName
forall l e. GenLocated l e -> e
unLoc Located RdrName
lbl)


checkMissingFields ::  ConLike -> HsRecordBinds GhcRn -> TcM ()
checkMissingFields :: ConLike -> HsRecordBinds GhcRn -> TcRn ()
checkMissingFields ConLike
con_like HsRecordBinds GhcRn
rbinds
  | [FieldLbl Name] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [FieldLbl Name]
field_labels   -- Not declared as a record;
                        -- But C{} is still valid if no strict fields
  = if (HsImplBang -> Bool) -> [HsImplBang] -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
any HsImplBang -> Bool
isBanged [HsImplBang]
field_strs then
        -- Illegal if any arg is strict
        SDoc -> TcRn ()
addErrTc (ConLike -> [FastString] -> SDoc
missingStrictFields ConLike
con_like [])
    else do
        Bool
warn <- WarningFlag -> TcRn Bool
forall gbl lcl. WarningFlag -> TcRnIf gbl lcl Bool
woptM WarningFlag
Opt_WarnMissingFields
        Bool -> TcRn () -> TcRn ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (Bool
warn Bool -> Bool -> Bool
&& [HsImplBang] -> Bool
forall (f :: * -> *) a. Foldable f => f a -> Bool
notNull [HsImplBang]
field_strs Bool -> Bool -> Bool
&& [FieldLbl Name] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [FieldLbl Name]
field_labels)
             (WarnReason -> Bool -> SDoc -> TcRn ()
warnTc (WarningFlag -> WarnReason
Reason WarningFlag
Opt_WarnMissingFields) Bool
True
                 (ConLike -> [FastString] -> SDoc
missingFields ConLike
con_like []))

  | Bool
otherwise = do              -- A record
    Bool -> TcRn () -> TcRn ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless ([FastString] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [FastString]
missing_s_fields)
           (SDoc -> TcRn ()
addErrTc (ConLike -> [FastString] -> SDoc
missingStrictFields ConLike
con_like [FastString]
missing_s_fields))

    Bool
warn <- WarningFlag -> TcRn Bool
forall gbl lcl. WarningFlag -> TcRnIf gbl lcl Bool
woptM WarningFlag
Opt_WarnMissingFields
    Bool -> TcRn () -> TcRn ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (Bool
warn Bool -> Bool -> Bool
&& [FastString] -> Bool
forall (f :: * -> *) a. Foldable f => f a -> Bool
notNull [FastString]
missing_ns_fields)
         (WarnReason -> Bool -> SDoc -> TcRn ()
warnTc (WarningFlag -> WarnReason
Reason WarningFlag
Opt_WarnMissingFields) Bool
True
             (ConLike -> [FastString] -> SDoc
missingFields ConLike
con_like [FastString]
missing_ns_fields))

  where
    missing_s_fields :: [FastString]
missing_s_fields
        = [ FieldLbl Name -> FastString
forall a. FieldLbl a -> FastString
flLabel FieldLbl Name
fl | (FieldLbl Name
fl, HsImplBang
str) <- [(FieldLbl Name, HsImplBang)]
field_info,
                 HsImplBang -> Bool
isBanged HsImplBang
str,
                 Bool -> Bool
not (FieldLbl Name
fl FieldLbl Name -> [Name] -> Bool
forall (t :: * -> *) a.
(Foldable t, Eq a) =>
FieldLbl a -> t a -> Bool
`elemField` [Name]
[XCFieldOcc GhcRn]
field_names_used)
          ]
    missing_ns_fields :: [FastString]
missing_ns_fields
        = [ FieldLbl Name -> FastString
forall a. FieldLbl a -> FastString
flLabel FieldLbl Name
fl | (FieldLbl Name
fl, HsImplBang
str) <- [(FieldLbl Name, HsImplBang)]
field_info,
                 Bool -> Bool
not (HsImplBang -> Bool
isBanged HsImplBang
str),
                 Bool -> Bool
not (FieldLbl Name
fl FieldLbl Name -> [Name] -> Bool
forall (t :: * -> *) a.
(Foldable t, Eq a) =>
FieldLbl a -> t a -> Bool
`elemField` [Name]
[XCFieldOcc GhcRn]
field_names_used)
          ]

    field_names_used :: [XCFieldOcc GhcRn]
field_names_used = HsRecFields GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
-> [XCFieldOcc GhcRn]
forall p arg. HsRecFields p arg -> [XCFieldOcc p]
hsRecFields HsRecFields GhcRn (GenLocated SrcSpan (HsExpr GhcRn))
HsRecordBinds GhcRn
rbinds
    field_labels :: [FieldLbl Name]
field_labels     = ConLike -> [FieldLbl Name]
conLikeFieldLabels ConLike
con_like

    field_info :: [(FieldLbl Name, HsImplBang)]
field_info = String
-> [FieldLbl Name] -> [HsImplBang] -> [(FieldLbl Name, HsImplBang)]
forall a b. String -> [a] -> [b] -> [(a, b)]
zipEqual String
"missingFields"
                          [FieldLbl Name]
field_labels
                          [HsImplBang]
field_strs

    field_strs :: [HsImplBang]
field_strs = ConLike -> [HsImplBang]
conLikeImplBangs ConLike
con_like

    FieldLbl a
fl elemField :: FieldLbl a -> t a -> Bool
`elemField` t a
flds = (a -> Bool) -> t a -> Bool
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
any (\ a
fl' -> FieldLbl a -> a
forall a. FieldLbl a -> a
flSelector FieldLbl a
fl a -> a -> Bool
forall a. Eq a => a -> a -> Bool
== a
fl') t a
flds

{-
************************************************************************
*                                                                      *
\subsection{Errors and contexts}
*                                                                      *
************************************************************************

Boring and alphabetical:
-}

fieldCtxt :: FieldLabelString -> SDoc
fieldCtxt :: FastString -> SDoc
fieldCtxt FastString
field_name
  = String -> SDoc
text String
"In the" SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (FastString -> SDoc
forall a. Outputable a => a -> SDoc
ppr FastString
field_name) SDoc -> SDoc -> SDoc
<+> PtrString -> SDoc
ptext (String -> PtrString
sLit String
"field of a record")

mk_op_msg :: LHsExpr GhcRn -> SDoc
mk_op_msg :: LHsExpr GhcRn -> SDoc
mk_op_msg LHsExpr GhcRn
op = String -> SDoc
text String
"The operator" SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (GenLocated SrcSpan (HsExpr GhcRn) -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenLocated SrcSpan (HsExpr GhcRn)
LHsExpr GhcRn
op) SDoc -> SDoc -> SDoc
<+> String -> SDoc
text String
"takes"

badFieldTypes :: [(FieldLabelString,TcType)] -> SDoc
badFieldTypes :: [(FastString, TcSigmaType)] -> SDoc
badFieldTypes [(FastString, TcSigmaType)]
prs
  = SDoc -> Int -> SDoc -> SDoc
hang (String -> SDoc
text String
"Record update for insufficiently polymorphic field"
                         SDoc -> SDoc -> SDoc
<> [(FastString, TcSigmaType)] -> SDoc
forall a. [a] -> SDoc
plural [(FastString, TcSigmaType)]
prs SDoc -> SDoc -> SDoc
<> SDoc
colon)
       Int
2 ([SDoc] -> SDoc
vcat [ FastString -> SDoc
forall a. Outputable a => a -> SDoc
ppr FastString
f SDoc -> SDoc -> SDoc
<+> SDoc
dcolon SDoc -> SDoc -> SDoc
<+> TcSigmaType -> SDoc
forall a. Outputable a => a -> SDoc
ppr TcSigmaType
ty | (FastString
f,TcSigmaType
ty) <- [(FastString, TcSigmaType)]
prs ])

badFieldsUpd
  :: [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
               -- Field names that don't belong to a single datacon
  -> [ConLike] -- Data cons of the type which the first field name belongs to
  -> SDoc
badFieldsUpd :: [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
-> [ConLike] -> SDoc
badFieldsUpd [LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
rbinds [ConLike]
data_cons
  = SDoc -> Int -> SDoc -> SDoc
hang (String -> SDoc
text String
"No constructor has all these fields:")
       Int
2 ([FastString] -> SDoc
forall a. Outputable a => [a] -> SDoc
pprQuotedList [FastString]
conflictingFields)
          -- See Note [Finding the conflicting fields]
  where
    -- A (preferably small) set of fields such that no constructor contains
    -- all of them.  See Note [Finding the conflicting fields]
    conflictingFields :: [FastString]
conflictingFields = case [(FastString, [Bool])]
nonMembers of
        -- nonMember belongs to a different type.
        (FastString
nonMember, [Bool]
_) : [(FastString, [Bool])]
_ -> [FastString
aMember, FastString
nonMember]
        [] -> let
            -- All of rbinds belong to one type. In this case, repeatedly add
            -- a field to the set until no constructor contains the set.

            -- Each field, together with a list indicating which constructors
            -- have all the fields so far.
            growingSets :: [(FieldLabelString, [Bool])]
            growingSets :: [(FastString, [Bool])]
growingSets = ((FastString, [Bool])
 -> (FastString, [Bool]) -> (FastString, [Bool]))
-> [(FastString, [Bool])] -> [(FastString, [Bool])]
forall a. (a -> a -> a) -> [a] -> [a]
scanl1 (FastString, [Bool])
-> (FastString, [Bool]) -> (FastString, [Bool])
forall a a. (a, [Bool]) -> (a, [Bool]) -> (a, [Bool])
combine [(FastString, [Bool])]
membership
            combine :: (a, [Bool]) -> (a, [Bool]) -> (a, [Bool])
combine (a
_, [Bool]
setMem) (a
field, [Bool]
fldMem)
              = (a
field, (Bool -> Bool -> Bool) -> [Bool] -> [Bool] -> [Bool]
forall a b c. (a -> b -> c) -> [a] -> [b] -> [c]
zipWith Bool -> Bool -> Bool
(&&) [Bool]
setMem [Bool]
fldMem)
            in
            -- Fields that don't change the membership status of the set
            -- are redundant and can be dropped.
            ([(FastString, [Bool])] -> FastString)
-> [[(FastString, [Bool])]] -> [FastString]
forall a b. (a -> b) -> [a] -> [b]
map ((FastString, [Bool]) -> FastString
forall a b. (a, b) -> a
fst ((FastString, [Bool]) -> FastString)
-> ([(FastString, [Bool])] -> (FastString, [Bool]))
-> [(FastString, [Bool])]
-> FastString
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [(FastString, [Bool])] -> (FastString, [Bool])
forall a. [a] -> a
head) ([[(FastString, [Bool])]] -> [FastString])
-> [[(FastString, [Bool])]] -> [FastString]
forall a b. (a -> b) -> a -> b
$ ((FastString, [Bool]) -> (FastString, [Bool]) -> Bool)
-> [(FastString, [Bool])] -> [[(FastString, [Bool])]]
forall a. (a -> a -> Bool) -> [a] -> [[a]]
groupBy ([Bool] -> [Bool] -> Bool
forall a. Eq a => a -> a -> Bool
(==) ([Bool] -> [Bool] -> Bool)
-> ((FastString, [Bool]) -> [Bool])
-> (FastString, [Bool])
-> (FastString, [Bool])
-> Bool
forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
`on` (FastString, [Bool]) -> [Bool]
forall a b. (a, b) -> b
snd) [(FastString, [Bool])]
growingSets

    aMember :: FastString
aMember = ASSERT( not (null members) ) fst (head members)
    ([(FastString, [Bool])]
members, [(FastString, [Bool])]
nonMembers) = ((FastString, [Bool]) -> Bool)
-> [(FastString, [Bool])]
-> ([(FastString, [Bool])], [(FastString, [Bool])])
forall a. (a -> Bool) -> [a] -> ([a], [a])
partition ([Bool] -> Bool
forall (t :: * -> *). Foldable t => t Bool -> Bool
or ([Bool] -> Bool)
-> ((FastString, [Bool]) -> [Bool]) -> (FastString, [Bool]) -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (FastString, [Bool]) -> [Bool]
forall a b. (a, b) -> b
snd) [(FastString, [Bool])]
membership

    -- For each field, which constructors contain the field?
    membership :: [(FieldLabelString, [Bool])]
    membership :: [(FastString, [Bool])]
membership = [(FastString, [Bool])] -> [(FastString, [Bool])]
forall a. [(a, [Bool])] -> [(a, [Bool])]
sortMembership ([(FastString, [Bool])] -> [(FastString, [Bool])])
-> [(FastString, [Bool])] -> [(FastString, [Bool])]
forall a b. (a -> b) -> a -> b
$
        (FastString -> (FastString, [Bool]))
-> [FastString] -> [(FastString, [Bool])]
forall a b. (a -> b) -> [a] -> [b]
map (\FastString
fld -> (FastString
fld, (UniqSet FastString -> Bool) -> [UniqSet FastString] -> [Bool]
forall a b. (a -> b) -> [a] -> [b]
map (FastString
fld FastString -> UniqSet FastString -> Bool
forall a. Uniquable a => a -> UniqSet a -> Bool
`elementOfUniqSet`) [UniqSet FastString]
fieldLabelSets)) ([FastString] -> [(FastString, [Bool])])
-> [FastString] -> [(FastString, [Bool])]
forall a b. (a -> b) -> a -> b
$
          (GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> FastString)
-> [GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> [FastString]
forall a b. (a -> b) -> [a] -> [b]
map (OccName -> FastString
occNameFS (OccName -> FastString)
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> OccName)
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> FastString
forall b c a. (b -> c) -> (a -> b) -> a -> c
. RdrName -> OccName
rdrNameOcc (RdrName -> OccName)
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> RdrName)
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> OccName
forall b c a. (b -> c) -> (a -> b) -> a -> c
. AmbiguousFieldOcc GhcTc -> RdrName
forall (p :: Pass). AmbiguousFieldOcc (GhcPass p) -> RdrName
rdrNameAmbiguousFieldOcc (AmbiguousFieldOcc GhcTc -> RdrName)
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> AmbiguousFieldOcc GhcTc)
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> RdrName
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
-> AmbiguousFieldOcc GhcTc
forall l e. GenLocated l e -> e
unLoc (GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
 -> AmbiguousFieldOcc GhcTc)
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc))
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> AmbiguousFieldOcc GhcTc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. HsRecField'
  (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl (HsRecField'
   (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
 -> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc))
-> (GenLocated
      SrcSpan
      (HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> HsRecField'
         (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> GenLocated
     SrcSpan
     (HsRecField'
        (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcTc)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenLocated
  SrcSpan
  (HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc) [GenLocated
   SrcSpan
   (HsRecField'
      (AmbiguousFieldOcc GhcTc) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecField' (AmbiguousFieldOcc GhcTc) (LHsExpr GhcRn)]
rbinds

    fieldLabelSets :: [UniqSet FieldLabelString]
    fieldLabelSets :: [UniqSet FastString]
fieldLabelSets = (ConLike -> UniqSet FastString)
-> [ConLike] -> [UniqSet FastString]
forall a b. (a -> b) -> [a] -> [b]
map ([FastString] -> UniqSet FastString
forall a. Uniquable a => [a] -> UniqSet a
mkUniqSet ([FastString] -> UniqSet FastString)
-> (ConLike -> [FastString]) -> ConLike -> UniqSet FastString
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (FieldLbl Name -> FastString) -> [FieldLbl Name] -> [FastString]
forall a b. (a -> b) -> [a] -> [b]
map FieldLbl Name -> FastString
forall a. FieldLbl a -> FastString
flLabel ([FieldLbl Name] -> [FastString])
-> (ConLike -> [FieldLbl Name]) -> ConLike -> [FastString]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ConLike -> [FieldLbl Name]
conLikeFieldLabels) [ConLike]
data_cons

    -- Sort in order of increasing number of True, so that a smaller
    -- conflicting set can be found.
    sortMembership :: [(a, [Bool])] -> [(a, [Bool])]
sortMembership =
      ((Int, (a, [Bool])) -> (a, [Bool]))
-> [(Int, (a, [Bool]))] -> [(a, [Bool])]
forall a b. (a -> b) -> [a] -> [b]
map (Int, (a, [Bool])) -> (a, [Bool])
forall a b. (a, b) -> b
snd ([(Int, (a, [Bool]))] -> [(a, [Bool])])
-> ([(a, [Bool])] -> [(Int, (a, [Bool]))])
-> [(a, [Bool])]
-> [(a, [Bool])]
forall b c a. (b -> c) -> (a -> b) -> a -> c
.
      ((Int, (a, [Bool])) -> (Int, (a, [Bool])) -> Ordering)
-> [(Int, (a, [Bool]))] -> [(Int, (a, [Bool]))]
forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy (Int -> Int -> Ordering
forall a. Ord a => a -> a -> Ordering
compare (Int -> Int -> Ordering)
-> ((Int, (a, [Bool])) -> Int)
-> (Int, (a, [Bool]))
-> (Int, (a, [Bool]))
-> Ordering
forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
`on` (Int, (a, [Bool])) -> Int
forall a b. (a, b) -> a
fst) ([(Int, (a, [Bool]))] -> [(Int, (a, [Bool]))])
-> ([(a, [Bool])] -> [(Int, (a, [Bool]))])
-> [(a, [Bool])]
-> [(Int, (a, [Bool]))]
forall b c a. (b -> c) -> (a -> b) -> a -> c
.
      ((a, [Bool]) -> (Int, (a, [Bool])))
-> [(a, [Bool])] -> [(Int, (a, [Bool]))]
forall a b. (a -> b) -> [a] -> [b]
map (\ item :: (a, [Bool])
item@(a
_, [Bool]
membershipRow) -> ([Bool] -> Int
countTrue [Bool]
membershipRow, (a, [Bool])
item))

    countTrue :: [Bool] -> Int
countTrue = (Bool -> Bool) -> [Bool] -> Int
forall a. (a -> Bool) -> [a] -> Int
count Bool -> Bool
forall a. a -> a
id

{-
Note [Finding the conflicting fields]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppose we have
  data A = A {a0, a1 :: Int}
         | B {b0, b1 :: Int}
and we see a record update
  x { a0 = 3, a1 = 2, b0 = 4, b1 = 5 }
Then we'd like to find the smallest subset of fields that no
constructor has all of.  Here, say, {a0,b0}, or {a0,b1}, etc.
We don't really want to report that no constructor has all of
{a0,a1,b0,b1}, because when there are hundreds of fields it's
hard to see what was really wrong.

We may need more than two fields, though; eg
  data T = A { x,y :: Int, v::Int }
          | B { y,z :: Int, v::Int }
          | C { z,x :: Int, v::Int }
with update
   r { x=e1, y=e2, z=e3 }, we

Finding the smallest subset is hard, so the code here makes
a decent stab, no more.  See #7989.
-}

mixedSelectors :: [Id] -> [Id] -> SDoc
mixedSelectors :: [Id] -> [Id] -> SDoc
mixedSelectors data_sels :: [Id]
data_sels@(Id
dc_rep_id:[Id]
_) pat_syn_sels :: [Id]
pat_syn_sels@(Id
ps_rep_id:[Id]
_)
  = PtrString -> SDoc
ptext
      (String -> PtrString
sLit String
"Cannot use a mixture of pattern synonym and record selectors") SDoc -> SDoc -> SDoc
$$
    String -> SDoc
text String
"Record selectors defined by"
      SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (Name -> SDoc
forall a. Outputable a => a -> SDoc
ppr (TyCon -> Name
tyConName TyCon
rep_dc))
      SDoc -> SDoc -> SDoc
<> String -> SDoc
text String
":"
      SDoc -> SDoc -> SDoc
<+> (Id -> SDoc) -> [Id] -> SDoc
forall a. (a -> SDoc) -> [a] -> SDoc
pprWithCommas Id -> SDoc
forall a. Outputable a => a -> SDoc
ppr [Id]
data_sels SDoc -> SDoc -> SDoc
$$
    String -> SDoc
text String
"Pattern synonym selectors defined by"
      SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (Name -> SDoc
forall a. Outputable a => a -> SDoc
ppr (PatSyn -> Name
patSynName PatSyn
rep_ps))
      SDoc -> SDoc -> SDoc
<> String -> SDoc
text String
":"
      SDoc -> SDoc -> SDoc
<+> (Id -> SDoc) -> [Id] -> SDoc
forall a. (a -> SDoc) -> [a] -> SDoc
pprWithCommas Id -> SDoc
forall a. Outputable a => a -> SDoc
ppr [Id]
pat_syn_sels
  where
    RecSelPatSyn PatSyn
rep_ps = Id -> RecSelParent
recordSelectorTyCon Id
ps_rep_id
    RecSelData TyCon
rep_dc = Id -> RecSelParent
recordSelectorTyCon Id
dc_rep_id
mixedSelectors [Id]
_ [Id]
_ = String -> SDoc
forall a. String -> a
panic String
"GHC.Tc.Gen.Expr: mixedSelectors emptylists"


missingStrictFields :: ConLike -> [FieldLabelString] -> SDoc
missingStrictFields :: ConLike -> [FastString] -> SDoc
missingStrictFields ConLike
con [FastString]
fields
  = SDoc
header SDoc -> SDoc -> SDoc
<> SDoc
rest
  where
    rest :: SDoc
rest | [FastString] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [FastString]
fields = SDoc
Outputable.empty  -- Happens for non-record constructors
                                           -- with strict fields
         | Bool
otherwise   = SDoc
colon SDoc -> SDoc -> SDoc
<+> (FastString -> SDoc) -> [FastString] -> SDoc
forall a. (a -> SDoc) -> [a] -> SDoc
pprWithCommas FastString -> SDoc
forall a. Outputable a => a -> SDoc
ppr [FastString]
fields

    header :: SDoc
header = String -> SDoc
text String
"Constructor" SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (ConLike -> SDoc
forall a. Outputable a => a -> SDoc
ppr ConLike
con) SDoc -> SDoc -> SDoc
<+>
             String -> SDoc
text String
"does not have the required strict field(s)"

missingFields :: ConLike -> [FieldLabelString] -> SDoc
missingFields :: ConLike -> [FastString] -> SDoc
missingFields ConLike
con [FastString]
fields
  = SDoc
header SDoc -> SDoc -> SDoc
<> SDoc
rest
  where
    rest :: SDoc
rest | [FastString] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [FastString]
fields = SDoc
Outputable.empty
         | Bool
otherwise = SDoc
colon SDoc -> SDoc -> SDoc
<+> (FastString -> SDoc) -> [FastString] -> SDoc
forall a. (a -> SDoc) -> [a] -> SDoc
pprWithCommas FastString -> SDoc
forall a. Outputable a => a -> SDoc
ppr [FastString]
fields
    header :: SDoc
header = String -> SDoc
text String
"Fields of" SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (ConLike -> SDoc
forall a. Outputable a => a -> SDoc
ppr ConLike
con) SDoc -> SDoc -> SDoc
<+>
             String -> SDoc
text String
"not initialised"

-- callCtxt fun args = text "In the call" <+> parens (ppr (foldl' mkHsApp fun args))

noPossibleParents :: [LHsRecUpdField GhcRn] -> SDoc
noPossibleParents :: [LHsRecUpdField GhcRn] -> SDoc
noPossibleParents [LHsRecUpdField GhcRn]
rbinds
  = SDoc -> Int -> SDoc -> SDoc
hang (String -> SDoc
text String
"No type has all these fields:")
       Int
2 ([GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)] -> SDoc
forall a. Outputable a => [a] -> SDoc
pprQuotedList [GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)]
fields)
  where
    fields :: [GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)]
fields = (Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
 -> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn))
-> [Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
-> [GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)]
forall a b. (a -> b) -> [a] -> [b]
map (HsRecField'
  (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)
forall id arg. HsRecField' id arg -> Located id
hsRecFieldLbl (HsRecField'
   (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
 -> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn))
-> (Located
      (HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
    -> HsRecField'
         (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> Located
     (HsRecField'
        (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> GenLocated SrcSpan (AmbiguousFieldOcc GhcRn)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Located
  (HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))
-> HsRecField'
     (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn))
forall l e. GenLocated l e -> e
unLoc) [Located
   (HsRecField'
      (AmbiguousFieldOcc GhcRn) (GenLocated SrcSpan (HsExpr GhcRn)))]
[LHsRecUpdField GhcRn]
rbinds

badOverloadedUpdate :: SDoc
badOverloadedUpdate :: SDoc
badOverloadedUpdate = String -> SDoc
text String
"Record update is ambiguous, and requires a type signature"

{-
************************************************************************
*                                                                      *
\subsection{Static Pointers}
*                                                                      *
************************************************************************
-}

-- | A data type to describe why a variable is not closed.
data NotClosedReason = NotLetBoundReason
                     | NotTypeClosed VarSet
                     | NotClosed Name NotClosedReason

-- | Checks if the given name is closed and emits an error if not.
--
-- See Note [Not-closed error messages].
checkClosedInStaticForm :: Name -> TcM ()
checkClosedInStaticForm :: Name -> TcRn ()
checkClosedInStaticForm Name
name = do
    TcTypeEnv
type_env <- TcM TcTypeEnv
getLclTypeEnv
    case TcTypeEnv -> Name -> Maybe NotClosedReason
checkClosed TcTypeEnv
type_env Name
name of
      Maybe NotClosedReason
Nothing -> () -> TcRn ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
      Just NotClosedReason
reason -> SDoc -> TcRn ()
addErrTc (SDoc -> TcRn ()) -> SDoc -> TcRn ()
forall a b. (a -> b) -> a -> b
$ Name -> NotClosedReason -> SDoc
explain Name
name NotClosedReason
reason
  where
    -- See Note [Checking closedness].
    checkClosed :: TcTypeEnv -> Name -> Maybe NotClosedReason
    checkClosed :: TcTypeEnv -> Name -> Maybe NotClosedReason
checkClosed TcTypeEnv
type_env Name
n = TcTypeEnv -> UniqSet Name -> Name -> Maybe NotClosedReason
checkLoop TcTypeEnv
type_env (Name -> UniqSet Name
unitNameSet Name
n) Name
n

    checkLoop :: TcTypeEnv -> NameSet -> Name -> Maybe NotClosedReason
    checkLoop :: TcTypeEnv -> UniqSet Name -> Name -> Maybe NotClosedReason
checkLoop TcTypeEnv
type_env UniqSet Name
visited Name
n =
      -- The @visited@ set is an accumulating parameter that contains the set of
      -- visited nodes, so we avoid repeating cycles in the traversal.
      case TcTypeEnv -> Name -> Maybe TcTyThing
forall a. NameEnv a -> Name -> Maybe a
lookupNameEnv TcTypeEnv
type_env Name
n of
        Just (ATcId { tct_id :: TcTyThing -> Id
tct_id = Id
tcid, tct_info :: TcTyThing -> IdBindingInfo
tct_info = IdBindingInfo
info }) -> case IdBindingInfo
info of
          IdBindingInfo
ClosedLet   -> Maybe NotClosedReason
forall a. Maybe a
Nothing
          IdBindingInfo
NotLetBound -> NotClosedReason -> Maybe NotClosedReason
forall a. a -> Maybe a
Just NotClosedReason
NotLetBoundReason
          NonClosedLet UniqSet Name
fvs Bool
type_closed -> [NotClosedReason] -> Maybe NotClosedReason
forall a. [a] -> Maybe a
listToMaybe ([NotClosedReason] -> Maybe NotClosedReason)
-> [NotClosedReason] -> Maybe NotClosedReason
forall a b. (a -> b) -> a -> b
$
            -- Look for a non-closed variable in fvs
            [ Name -> NotClosedReason -> NotClosedReason
NotClosed Name
n' NotClosedReason
reason
            | Name
n' <- UniqSet Name -> [Name]
nameSetElemsStable UniqSet Name
fvs
            , Bool -> Bool
not (Name -> UniqSet Name -> Bool
elemNameSet Name
n' UniqSet Name
visited)
            , Just NotClosedReason
reason <- [TcTypeEnv -> UniqSet Name -> Name -> Maybe NotClosedReason
checkLoop TcTypeEnv
type_env (UniqSet Name -> Name -> UniqSet Name
extendNameSet UniqSet Name
visited Name
n') Name
n']
            ] [NotClosedReason] -> [NotClosedReason] -> [NotClosedReason]
forall a. [a] -> [a] -> [a]
++
            if Bool
type_closed then
              []
            else
              -- We consider non-let-bound variables easier to figure out than
              -- non-closed types, so we report non-closed types to the user
              -- only if we cannot spot the former.
              [ VarSet -> NotClosedReason
NotTypeClosed (VarSet -> NotClosedReason) -> VarSet -> NotClosedReason
forall a b. (a -> b) -> a -> b
$ TcSigmaType -> VarSet
tyCoVarsOfType (Id -> TcSigmaType
idType Id
tcid) ]
        -- The binding is closed.
        Maybe TcTyThing
_ -> Maybe NotClosedReason
forall a. Maybe a
Nothing

    -- Converts a reason into a human-readable sentence.
    --
    -- @explain name reason@ starts with
    --
    -- "<name> is used in a static form but it is not closed because it"
    --
    -- and then follows a list of causes. For each id in the path, the text
    --
    -- "uses <id> which"
    --
    -- is appended, yielding something like
    --
    -- "uses <id> which uses <id1> which uses <id2> which"
    --
    -- until the end of the path is reached, which is reported as either
    --
    -- "is not let-bound"
    --
    -- when the final node is not let-bound, or
    --
    -- "has a non-closed type because it contains the type variables:
    -- v1, v2, v3"
    --
    -- when the final node has a non-closed type.
    --
    explain :: Name -> NotClosedReason -> SDoc
    explain :: Name -> NotClosedReason -> SDoc
explain Name
name NotClosedReason
reason =
      SDoc -> SDoc
quotes (Name -> SDoc
forall a. Outputable a => a -> SDoc
ppr Name
name) SDoc -> SDoc -> SDoc
<+> String -> SDoc
text String
"is used in a static form but it is not closed"
                        SDoc -> SDoc -> SDoc
<+> String -> SDoc
text String
"because it"
                        SDoc -> SDoc -> SDoc
$$
                        [SDoc] -> SDoc
sep (NotClosedReason -> [SDoc]
causes NotClosedReason
reason)

    causes :: NotClosedReason -> [SDoc]
    causes :: NotClosedReason -> [SDoc]
causes NotClosedReason
NotLetBoundReason = [String -> SDoc
text String
"is not let-bound."]
    causes (NotTypeClosed VarSet
vs) =
      [ String -> SDoc
text String
"has a non-closed type because it contains the"
      , String -> SDoc
text String
"type variables:" SDoc -> SDoc -> SDoc
<+>
        VarSet -> ([Id] -> SDoc) -> SDoc
pprVarSet VarSet
vs ([SDoc] -> SDoc
hsep ([SDoc] -> SDoc) -> ([Id] -> [SDoc]) -> [Id] -> SDoc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. SDoc -> [SDoc] -> [SDoc]
punctuate SDoc
comma ([SDoc] -> [SDoc]) -> ([Id] -> [SDoc]) -> [Id] -> [SDoc]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (Id -> SDoc) -> [Id] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map (SDoc -> SDoc
quotes (SDoc -> SDoc) -> (Id -> SDoc) -> Id -> SDoc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> SDoc
forall a. Outputable a => a -> SDoc
ppr))
      ]
    causes (NotClosed Name
n NotClosedReason
reason) =
      let msg :: SDoc
msg = String -> SDoc
text String
"uses" SDoc -> SDoc -> SDoc
<+> SDoc -> SDoc
quotes (Name -> SDoc
forall a. Outputable a => a -> SDoc
ppr Name
n) SDoc -> SDoc -> SDoc
<+> String -> SDoc
text String
"which"
       in case NotClosedReason
reason of
            NotClosed Name
_ NotClosedReason
_ -> SDoc
msg SDoc -> [SDoc] -> [SDoc]
forall a. a -> [a] -> [a]
: NotClosedReason -> [SDoc]
causes NotClosedReason
reason
            NotClosedReason
_   -> let ([SDoc]
xs0, [SDoc]
xs1) = Int -> [SDoc] -> ([SDoc], [SDoc])
forall a. Int -> [a] -> ([a], [a])
splitAt Int
1 ([SDoc] -> ([SDoc], [SDoc])) -> [SDoc] -> ([SDoc], [SDoc])
forall a b. (a -> b) -> a -> b
$ NotClosedReason -> [SDoc]
causes NotClosedReason
reason
                    in (SDoc -> SDoc) -> [SDoc] -> [SDoc]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (SDoc
msg SDoc -> SDoc -> SDoc
<+>) [SDoc]
xs0 [SDoc] -> [SDoc] -> [SDoc]
forall a. [a] -> [a] -> [a]
++ [SDoc]
xs1

-- Note [Not-closed error messages]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
-- When variables in a static form are not closed, we go through the trouble
-- of explaining why they aren't.
--
-- Thus, the following program
--
-- > {-# LANGUAGE StaticPointers #-}
-- > module M where
-- >
-- > f x = static g
-- >   where
-- >     g = h
-- >     h = x
--
-- produces the error
--
--    'g' is used in a static form but it is not closed because it
--    uses 'h' which uses 'x' which is not let-bound.
--
-- And a program like
--
-- > {-# LANGUAGE StaticPointers #-}
-- > module M where
-- >
-- > import Data.Typeable
-- > import GHC.StaticPtr
-- >
-- > f :: Typeable a => a -> StaticPtr TypeRep
-- > f x = const (static (g undefined)) (h x)
-- >   where
-- >     g = h
-- >     h = typeOf
--
-- produces the error
--
--    'g' is used in a static form but it is not closed because it
--    uses 'h' which has a non-closed type because it contains the
--    type variables: 'a'
--

-- Note [Checking closedness]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~
--
-- @checkClosed@ checks if a binding is closed and returns a reason if it is
-- not.
--
-- The bindings define a graph where the nodes are ids, and there is an edge
-- from @id1@ to @id2@ if the rhs of @id1@ contains @id2@ among its free
-- variables.
--
-- When @n@ is not closed, it has to exist in the graph some node reachable
-- from @n@ that it is not a let-bound variable or that it has a non-closed
-- type. Thus, the "reason" is a path from @n@ to this offending node.
--
-- When @n@ is not closed, we traverse the graph reachable from @n@ to build
-- the reason.
--