diff options
Diffstat (limited to 'compiler/parser/Parser.y.pp')
| -rw-r--r-- | compiler/parser/Parser.y.pp | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/compiler/parser/Parser.y.pp b/compiler/parser/Parser.y.pp index 21f8782f6f..62132277d9 100644 --- a/compiler/parser/Parser.y.pp +++ b/compiler/parser/Parser.y.pp @@ -55,7 +55,7 @@ import FastString import Maybes ( orElse ) import Outputable -import Control.Monad ( unless ) +import Control.Monad ( unless, liftM ) import GHC.Exts import Data.Char import Control.Monad ( mplus ) @@ -275,6 +275,7 @@ incorrect. '::' { L _ ITdcolon } '=' { L _ ITequal } '\\' { L _ ITlam } + 'lcase' { L _ ITlcase } '|' { L _ ITvbar } '<-' { L _ ITlarrow } '->' { L _ ITrarrow } @@ -1388,9 +1389,13 @@ exp10 :: { LHsExpr RdrName } (unguardedGRHSs $6) ]) } | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 } + | '\\' 'lcase' altslist + { LL $ HsLamCase placeHolderType (mkMatchGroup (unLoc $3)) } | 'if' exp optSemi 'then' exp optSemi 'else' exp {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >> return (LL $ mkHsIf $2 $5 $8) } + | 'if' gdpats {% hintMultiWayIf (getLoc $1) >> + return (LL $ HsMultiIf placeHolderType (reverse $ unLoc $2)) } | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) } | '-' fexp { LL $ NegApp $2 noSyntaxExpr } @@ -2138,4 +2143,11 @@ fileSrcSpan = do l <- getSrcLoc; let loc = mkSrcLoc (srcLocFile l) 1 1; return (mkSrcSpan loc loc) + +-- Hint about the MultiWayIf extension +hintMultiWayIf :: SrcSpan -> P () +hintMultiWayIf span = do + mwiEnabled <- liftM ((Opt_MultiWayIf `xopt`) . dflags) getPState + unless mwiEnabled $ parseErrorSDoc span $ + text "Multi-way if-expressions need -XMultiWayIf turned on" } |