import Var
import Type
import DataCon
-import OccName
import Name
import BasicTypes
import SrcLoc
mkHsPar :: LHsExpr id -> LHsExpr id
mkHsPar e = L (getLoc e) (HsPar e)
--- gaw 2004
mkSimpleMatch :: [LPat id] -> LHsExpr id -> LMatch id
mkSimpleMatch pats rhs
= L loc $
- Match pats Nothing (GRHSs (unguardedRHS rhs) emptyLocalBinds)
+ Match pats Nothing (unguardedGRHSs rhs)
where
loc = case pats of
[] -> getLoc rhs
(pat:_) -> combineSrcSpans (getLoc pat) (getLoc rhs)
+unguardedGRHSs :: LHsExpr id -> GRHSs id
+unguardedGRHSs rhs = GRHSs (unguardedRHS rhs) emptyLocalBinds
+
unguardedRHS :: LHsExpr id -> [LGRHS id]
unguardedRHS rhs@(L loc _) = [L loc (GRHS [] rhs)]
go (TuplePat pats _ _) = foldr collectl bndrs pats
go (ConPatIn c ps) = foldr collectl bndrs (hsConArgs ps)
- go (ConPatOut { pat_dicts = ds,
- pat_binds = bs, pat_args = ps })
- = map noLoc ds
- ++ collectHsBindLocatedBinders bs
- ++ foldr collectl bndrs (hsConArgs ps)
+ go (ConPatOut {pat_args=ps}) = foldr collectl bndrs (hsConArgs ps)
+ -- See Note [Dictionary binders in ConPatOut]
go (LitPat _) = bndrs
go (NPat _ _ _ _) = bndrs
go (NPlusKPat n _ _ _) = n : bndrs
-
+
go (SigPatIn pat _) = collectl pat bndrs
go (SigPatOut pat _) = collectl pat bndrs
go (TypePat ty) = bndrs
go (CoPat _ pat ty) = collectl (noLoc pat) bndrs
\end{code}
+Note [Dictionary binders in ConPatOut]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Do *not* gather (a) dictionary and (b) dictionary bindings as binders
+of a ConPatOut pattern. For most calls it doesn't matter, because
+it's pre-typechecker and there are no ConPatOuts. But it does matter
+more in the desugarer; for example, DsUtils.mkSelectorBinds uses
+collectPatBinders. In a lazy pattern, for example f ~(C x y) = ...,
+we want to generate bindings for x,y but not for dictionaries bound by
+C. (The type checker ensures they would not be used.)
+
\begin{code}
collectSigTysFromPats :: [InPat name] -> [LHsType name]
collectSigTysFromPats pats = foldr collect_lpat [] pats