{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ViewPatterns, MultiParamTypeClasses , FlexibleInstances, FlexibleContexts #-}
{-# LANGUAGE TupleSections #-}
{-# OPTIONS_GHC -Wno-unused-top-binds #-}
module GHC.Util.HsExpr (
noSyntaxExpr'
, isTag', isDol', isDot', isSection', isRecConstr', isRecUpdate', isVar', isPar', isApp', isAnyApp', isLexeme', isReturn'
, dotApp'
, simplifyExp', niceLambda', niceDotApp'
, Brackets'(..)
, rebracket1', appsBracket', transformAppsM', fromApps', apps', universeApps', universeParentExp'
, varToStr', strToVar'
, paren', fromChar'
, replaceBranches'
) where
import HsSyn
import BasicTypes
import SrcLoc
import FastString
import RdrName
import OccName
import Bag(bagToList)
import TysWiredIn
import TcEvidence
import Name
import GHC.Util.Brackets
import GHC.Util.View
import GHC.Util.FreeVars
import GHC.Util.W
import GHC.Util.Pat
import Control.Applicative
import Control.Monad.Trans.State
import Data.Data
import Data.Generics.Uniplate.Data
import Data.List.Extra
import Refact.Types hiding (Match)
import qualified Refact.Types as R (SrcSpan)
noSyntaxExpr' :: SyntaxExpr GhcPs
noSyntaxExpr' =
SyntaxExpr
(HsLit noExt
(HsString NoSourceText (fsLit "noSyntaxExpr")))
[] WpHole
dotApp' :: LHsExpr GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs
dotApp' x y = noLoc $ OpApp noExt x (noLoc $ HsVar noExt (noLoc $ mkVarUnqual (fsLit "."))) y
paren' :: LHsExpr GhcPs -> LHsExpr GhcPs
paren' x
| isAtom' x = x
| otherwise = addParen' x
isTag' :: LHsExpr GhcPs -> String -> Bool
isTag' (LL _ (HsVar _ (L _ s))) tag = occNameString (rdrNameOcc s) == tag
isTag' _ _ = False
isVar',isReturn',isLexeme',isDotApp',isRecUpdate',isRecConstr',isDol',isDot' :: LHsExpr GhcPs -> Bool
isPar' (LL _ HsPar{}) = True; isPar' _ = False
isVar' (LL _ HsVar{}) = True; isVar' _ = False
isDot' x = isTag' x "."
isDol' x = isTag' x "$"
isReturn' x = isTag' x "return" || isTag' x "pure"
isRecConstr' (LL _ RecordCon{}) = True; isRecConstr' _ = False
isRecUpdate' (LL _ RecordUpd{}) = True; isRecUpdate' _ = False
isDotApp' (LL _ (OpApp _ _ op _)) = isDot' op; isDotApp' _ = False
isLexeme' (LL _ HsVar{}) = True;isLexeme' (LL _ HsOverLit{}) = True;isLexeme' (LL _ HsLit{}) = True;isLexeme' _ = False
universeParentExp' :: Data a => a -> [(Maybe (Int, LHsExpr GhcPs), LHsExpr GhcPs)]
universeParentExp' xs = concat [(Nothing, x) : f x | x <- childrenBi xs]
where f p = concat [(Just (i,p), c) : f c | (i,c) <- zip [0..] $ children p]
apps' :: [LHsExpr GhcPs] -> LHsExpr GhcPs
apps' = foldl1' mkApp where mkApp x y = noLoc (HsApp noExt x y)
fromApps' :: LHsExpr GhcPs -> [LHsExpr GhcPs]
fromApps' (LL _ (HsApp _ x y)) = fromApps' x ++ [y]
fromApps' x = [x]
childrenApps' :: LHsExpr GhcPs -> [LHsExpr GhcPs]
childrenApps' (LL _ (HsApp _ x y)) = childrenApps' x ++ [y]
childrenApps' x = children x
universeApps' :: LHsExpr GhcPs -> [LHsExpr GhcPs]
universeApps' x = x : concatMap universeApps' (childrenApps' x)
descendApps' :: (LHsExpr GhcPs -> LHsExpr GhcPs) -> LHsExpr GhcPs -> LHsExpr GhcPs
descendApps' f (LL l (HsApp _ x y)) = LL l $ HsApp noExt (descendApps' f x) (f y)
descendApps' f x = descend f x
descendAppsM' :: Monad m => (LHsExpr GhcPs -> m (LHsExpr GhcPs)) -> LHsExpr GhcPs -> m (LHsExpr GhcPs)
descendAppsM' f (LL l (HsApp _ x y)) = liftA2 (\x y -> LL l $ HsApp noExt x y) (descendAppsM' f x) (f y)
descendAppsM' f x = descendM f x
transformApps' :: (LHsExpr GhcPs -> LHsExpr GhcPs) -> LHsExpr GhcPs -> LHsExpr GhcPs
transformApps' f = f . descendApps' (transformApps' f)
transformAppsM' :: Monad m => (LHsExpr GhcPs -> m (LHsExpr GhcPs)) -> LHsExpr GhcPs -> m (LHsExpr GhcPs)
transformAppsM' f x = f =<< descendAppsM' (transformAppsM' f) x
descendIndex' :: Data a => (Int -> a -> a) -> a -> a
descendIndex' f x = flip evalState 0 $ flip descendM x $ \y -> do
i <- get
modify (+1)
return $ f i y
descendBracket' :: (LHsExpr GhcPs -> (Bool, LHsExpr GhcPs)) -> LHsExpr GhcPs -> LHsExpr GhcPs
descendBracket' op x = descendIndex' g x
where
g i y = if a then f i b else b
where (a, b) = op y
f i y@(LL _ e) | needBracket' i x y = addParen' y
f _ y = y
rebracket1' :: LHsExpr GhcPs -> LHsExpr GhcPs
rebracket1' = descendBracket' (True, )
appsBracket' :: [LHsExpr GhcPs] -> LHsExpr GhcPs
appsBracket' = foldl1 mkApp
where mkApp x y = rebracket1' (noLoc $ HsApp noExt x y)
varToStr' :: LHsExpr GhcPs -> String
varToStr' (LL _ (HsVar _ (L _ n)))
| n == consDataCon_RDR = ":"
| n == nameRdrName nilDataConName = "[]"
| n == nameRdrName (getName (tupleDataCon Boxed 0)) = "()"
| otherwise = occNameString (rdrNameOcc n)
varToStr' _ = ""
strToVar' :: String -> LHsExpr GhcPs
strToVar' x = noLoc $ HsVar noExt (noLoc $ mkRdrUnqual (mkVarOcc x))
simplifyExp' :: LHsExpr GhcPs -> LHsExpr GhcPs
simplifyExp' (LL l (OpApp _ x op y)) | isDol' op = LL l (HsApp noExt x (noLoc (HsPar noExt y)))
simplifyExp' e@(LL _ (HsLet _ (LL _ (HsValBinds _ (ValBinds _ binds []))) z)) =
case bagToList binds of
[LL _ (FunBind _ _(MG _ (LL _ [LL _ (Match _(FunRhs (LL _ x) _ _) [] (GRHSs _[LL _ (GRHS _ [] y)] (LL _ (EmptyLocalBinds _))))]) _) _ _)]
| occNameString (rdrNameOcc x) `notElem` vars' y && length [() | Unqual a <- universeBi z, a == rdrNameOcc x] <= 1 ->
transform f z
where f (view' -> Var_' x') | occNameString (rdrNameOcc x) == x' = paren' y
f x = x
_ -> e
simplifyExp' e = e
niceDotApp' :: LHsExpr GhcPs -> LHsExpr GhcPs -> LHsExpr GhcPs
niceDotApp' (LL _ (HsVar _ (L _ r))) b | occNameString (rdrNameOcc r) == "$" = b
niceDotApp' a b = dotApp' a b
niceLambda' :: [String] -> LHsExpr GhcPs -> LHsExpr GhcPs
niceLambda' ss e = fst (niceLambdaR' ss e)
allowRightSection x = x `notElem` ["-","#"]
allowLeftSection x = x /= "#"
niceLambdaR' :: [String]
-> LHsExpr GhcPs
-> (LHsExpr GhcPs, R.SrcSpan
-> [Refactoring R.SrcSpan])
niceLambdaR' xs (LL _ (HsPar _ x)) = niceLambdaR' xs x
niceLambdaR' [x] (view' -> App2' op@(LL _ (HsVar _ (L _ tag))) l r)
| isLexeme' r, view' l == Var_' x, x `notElem` vars' r, allowRightSection (occNameString $ rdrNameOcc tag) =
let e = rebracket1' $ addParen' (noLoc $ SectionR noExt op r)
in (e, const [])
niceLambdaR' [x] y
| Just (z, subts) <- factor y, x `notElem` vars' z = (z, const [])
where
factor :: LHsExpr GhcPs -> Maybe (LHsExpr GhcPs, [LHsExpr GhcPs])
factor y@(LL _ (HsApp _ ini lst)) | view' lst == Var_' x = Just (ini, [ini])
factor y@(LL _ (HsApp _ ini lst)) | Just (z, ss) <- factor lst
= let r = niceDotApp' ini z
in if eqLoc' r z then Just (r, ss) else Just (r, ini : ss)
factor (LL _ (OpApp _ y op (factor -> Just (z, ss))))| isDol' op
= let r = niceDotApp' y z
in if eqLoc' r z then Just (r, ss) else Just (r, y : ss)
factor (LL _ (HsPar _ y@(LL _ HsApp{}))) = factor y
factor _ = Nothing
niceLambdaR' [x,y] (LL _ (OpApp _ (view' -> Var_' x1) op@(LL _ HsVar {}) (view' -> Var_' y1)))
| x == x1, y == y1, vars' op `disjoint` [x, y] = (op, const [])
niceLambdaR' [x, y] (view' -> App2' op (view' -> Var_' y1) (view' -> Var_' x1))
| x == x1, y == y1, vars' op `disjoint` [x, y] = (noLoc $ HsApp noExt (strToVar' "flip") op, const [])
niceLambdaR' ss e =
let grhs = noLoc $ GRHS noExt [] e :: LGRHS GhcPs (LHsExpr GhcPs)
grhss = GRHSs {grhssExt = noExt, grhssGRHSs=[grhs], grhssLocalBinds=noLoc $ EmptyLocalBinds noExt}
match = noLoc $ Match {m_ext=noExt, m_ctxt=LambdaExpr, m_pats=map strToPat' ss, m_grhss=grhss} :: LMatch GhcPs (LHsExpr GhcPs)
matchGroup = MG {mg_ext=noExt, mg_origin=Generated, mg_alts=noLoc [match]}
in (noLoc $ HsLam noExt matchGroup, const [])
fromChar' :: LHsExpr GhcPs -> Maybe Char
fromChar' (LL _ (HsLit _ (HsChar _ x))) = Just x
fromChar' _ = Nothing
replaceBranches' :: LHsExpr GhcPs -> ([LHsExpr GhcPs], [LHsExpr GhcPs] -> LHsExpr GhcPs)
replaceBranches' (LL l (HsIf _ _ a b c)) = ([b, c], \[b, c] -> cL l (HsIf noExt Nothing a b c))
replaceBranches' (LL s (HsCase _ a (MG _ (L l bs) FromSource))) =
(concatMap f bs, \xs -> cL s (HsCase noExt a (MG noExt (cL l (g bs xs)) Generated)))
where
f :: LMatch GhcPs (LHsExpr GhcPs) -> [LHsExpr GhcPs]
f (LL _ (Match _ CaseAlt _ (GRHSs _ xs _))) = [x | (LL _ (GRHS _ _ x)) <- xs]
f _ = undefined
g :: [LMatch GhcPs (LHsExpr GhcPs)] -> [LHsExpr GhcPs] -> [LMatch GhcPs (LHsExpr GhcPs)]
g (LL s1 (Match _ CaseAlt a (GRHSs _ ns b)) : rest) xs =
cL s1 (Match noExt CaseAlt a (GRHSs noExt [cL a (GRHS noExt gs x) | (LL a (GRHS _ gs _), x) <- zip ns as] b)) : g rest bs
where (as, bs) = splitAt (length ns) xs
g [] [] = []
g _ _ = error "GHC.Util.HsExpr.replaceBranches': internal invariant failed, lists are of differing lengths"
replaceBranches' x = ([], \[] -> x)