checkValSig (L l (HsVar v)) ty
| isUnqual v && not (isDataOcc (rdrNameOcc v))
= return (TypeSig (L l v) ty)
-checkValSig lhs@(L l _) _
- | looks_like_foreign lhs
- = parseError l "Invalid type signature; perhaps you meant to use -XForeignFunctionInterface?"
- | otherwise
- = parseError l "Invalid type signature: should be of form <variable> :: <type>"
+checkValSig lhs@(L l _) ty
+ = parseErrorSDoc l ((text "Invalid type signature:" <+>
+ ppr lhs <+> text "::" <+> ppr ty)
+ $$ text hint)
where
+ hint = if looks_like_foreign lhs
+ then "Perhaps you meant to use -XForeignFunctionInterface?"
+ else "Should be of form <variable> :: <type>"
-- A common error is to forget the ForeignFunctionInterface flag
-- so check for that, and suggest. cf Trac #3805
-- Sadly 'foreign import' still barfs 'parse error' because 'import' is a keyword