[project @ 2005-10-06 10:38:54 by simonmar]

add splitHsFunType

From: Autrijus Tang <autrijus@autrijus.org>

diff --git a/ghc/compiler/hsSyn/HsTypes.lhs b/ghc/compiler/hsSyn/HsTypes.lhs
index 3089050..8ad5940 100644 (file)
--- a/ghc/compiler/hsSyn/HsTypes.lhs
+++ b/ghc/compiler/hsSyn/HsTypes.lhs
@@ -17,7 +17,7 @@ module HsTypes (
        mkExplicitHsForAllTy, mkImplicitHsForAllTy, 
        hsTyVarName, hsTyVarNames, replaceTyVarName,
        hsLTyVarName, hsLTyVarNames, hsLTyVarLocName, hsLTyVarLocNames,
-       splitHsInstDeclTy,
+       splitHsInstDeclTy, splitHsFunType,
        
        -- Type place holder
        PostTcType, placeHolderType,
@@ -235,6 +235,13 @@ splitHsInstDeclTy inst_ty
   where
     split_tau tvs cxt (HsPredTy (HsClassP cls tys)) = (tvs, cxt, cls, tys)
     split_tau tvs cxt (HsParTy (L _ ty))           = split_tau tvs cxt ty
+
+-- Splits HsType into the (init, last) parts
+splitHsFunType :: LHsType name -> ([LHsType name], LHsType name)
+splitHsFunType (L l (HsFunTy x y)) = (x:args, res)
+  where
+  (args, res) = splitHsFunType y
+splitHsFunType other = ([], other)
 \end{code}