-----------------------------------------------------------------------------
-- 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 '='.
: '|' 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))))