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| author | simonmar@microsoft.com <unknown> | 2007-06-28 08:11:05 +0000 |
|---|---|---|
| committer | simonmar@microsoft.com <unknown> | 2007-06-28 08:11:05 +0000 |
| commit | 52dead8037b16f86a60b4af234d1cf86dba9cee2 (patch) | |
| tree | 21a3ba888db710b520ff37a599a5a060f9ecf53c /compiler | |
| parent | 1723d79af0638a1e96e2ae9e41208f7b86872bbc (diff) | |
| download | haskell-52dead8037b16f86a60b4af234d1cf86dba9cee2.tar.gz | |
Fix typechecking bug with implicit parameters (Trac #1445)
tcSplitFunTy_maybe wasn't dealing with types like
(?x::Bool) => Int
Here, tcSplitFunTy_maybe should fail (as it would if there
was a for-all), because the type is a quantified type.
See Trac #1445, and test tc230.
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/typecheck/TcType.lhs | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/compiler/typecheck/TcType.lhs b/compiler/typecheck/TcType.lhs index 59286304da..01796c385d 100644 --- a/compiler/typecheck/TcType.lhs +++ b/compiler/typecheck/TcType.lhs @@ -715,9 +715,16 @@ tcSplitFunTys ty = case tcSplitFunTy_maybe ty of (args,res') = tcSplitFunTys res tcSplitFunTy_maybe :: Type -> Maybe (Type, Type) -tcSplitFunTy_maybe ty | Just ty' <- tcView ty = tcSplitFunTy_maybe ty' -tcSplitFunTy_maybe (FunTy arg res) = Just (arg, res) -tcSplitFunTy_maybe other = Nothing +tcSplitFunTy_maybe ty | Just ty' <- tcView ty = tcSplitFunTy_maybe ty' +tcSplitFunTy_maybe (FunTy arg res) | not (isPredTy arg) = Just (arg, res) +tcSplitFunTy_maybe other = Nothing + -- Note the (not (isPredTy arg)) guard + -- Consider (?x::Int) => Bool + -- We don't want to treat this as a function type! + -- A concrete example is test tc230: + -- f :: () -> (?p :: ()) => () -> () + -- + -- g = f () () tcSplitFunTysN :: TcRhoType |