X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FParser.y.pp;h=e7c991b36a3bc6a99b6a96f0ccb7ea62aefc3526;hp=212a79ce3695ad00bcabefff13debcb510592485;hb=c75d5fc876279575226ec22a27ce056851128ade;hpb=b06d623b2e367a572de5daf06d6a0b12c2740471 diff --git a/compiler/parser/Parser.y.pp b/compiler/parser/Parser.y.pp index 212a79c..e7c991b 100644 --- a/compiler/parser/Parser.y.pp +++ b/compiler/parser/Parser.y.pp @@ -1168,7 +1168,9 @@ deriving :: { Located (Maybe [LHsType RdrName]) } ----------------------------------------------------------------------------- -- Value definitions -{- There's an awkward overlap with a type signature. Consider +{- Note [Declaration/signature overlap] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +There's an awkward overlap with a type signature. Consider f :: Int -> Int = ...rhs... Then we can't tell whether it's a type signature or a value definition with a result signature until we see the '='. @@ -1220,10 +1222,9 @@ gdrh :: { LGRHS RdrName } : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 } sigdecl :: { Located (OrdList (LHsDecl RdrName)) } - : infixexp '::' sigtypedoc - {% do s <- checkValSig $1 $3; - return (LL $ unitOL (LL $ SigD s)) } - -- See the above notes for why we need infixexp here + : infixexp '::' sigtypedoc {% do s <- checkValSig $1 $3 + ; return (LL $ unitOL (LL $ SigD s)) } + -- See Note [Declaration/signature overlap] for why we need infixexp here | var ',' sig_vars '::' sigtypedoc { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] } | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1)))) @@ -1416,7 +1417,7 @@ texp :: { LHsExpr RdrName } | qopm infixexp { LL $ SectionR $1 $2 } -- View patterns get parenthesized above - | exp '->' exp { LL $ EViewPat $1 $3 } + | exp '->' texp { LL $ EViewPat $1 $3 } -- Always at least one comma tup_exprs :: { [HsTupArg RdrName] }