X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FhsSyn%2FHsUtils.lhs;h=d30cd1bdc381ef5171edf5bb400f209412c42797;hb=e86da1bb671f77ec08d400a2a6569b6ee7a805ef;hp=6efddcd0696cf91049be4df461666547dba2ad90;hpb=5822cb8d13aa3c05d2b46b4510c13d94b902eb21;p=ghc-hetmet.git

diff --git a/compiler/hsSyn/HsUtils.lhs b/compiler/hsSyn/HsUtils.lhs
index 6efddcd..d30cd1b 100644
--- a/compiler/hsSyn/HsUtils.lhs
+++ b/compiler/hsSyn/HsUtils.lhs
@@ -13,6 +13,13 @@ which deal with the intantiated versions are located elsewhere:
    Id			typecheck/TcHsSyn	
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
 module HsUtils where
 
 #include "HsVersions.h"
@@ -25,6 +32,7 @@ import HsLit
 
 import RdrName
 import Var
+import Coercion
 import Type
 import DataCon
 import Name
@@ -80,7 +88,15 @@ mkLHsWrap co_fn (L loc e) = L loc (mkHsWrap co_fn e)
 
 mkHsWrap :: HsWrapper -> HsExpr id -> HsExpr id
 mkHsWrap co_fn e | isIdHsWrapper co_fn = e
-		 | otherwise	      = HsWrap co_fn e
+		 | otherwise	       = HsWrap co_fn e
+
+mkHsWrapCoI :: CoercionI -> HsExpr id -> HsExpr id
+mkHsWrapCoI IdCo     e = e
+mkHsWrapCoI (ACo co) e = mkHsWrap (WpCo co) e
+
+coiToHsWrapper :: CoercionI -> HsWrapper
+coiToHsWrapper IdCo     = idHsWrapper
+coiToHsWrapper (ACo co) = WpCo co
 
 mkHsLam :: [LPat id] -> LHsExpr id -> LHsExpr id
 mkHsLam pats body = mkHsPar (L (getLoc body) (HsLam matches))
@@ -120,7 +136,7 @@ mkHsFractional f       = HsFractional f  noSyntaxExpr
 mkHsIsString   s       = HsIsString   s  noSyntaxExpr
 mkHsDo ctxt stmts body = HsDo ctxt stmts body placeHolderType
 
-mkNPat lit neg     = NPat lit neg noSyntaxExpr placeHolderType
+mkNPat lit neg     = NPat lit neg noSyntaxExpr
 mkNPlusKPat id lit = NPlusKPat id lit noSyntaxExpr noSyntaxExpr
 
 mkExprStmt expr	    = ExprStmt expr noSyntaxExpr placeHolderType
@@ -282,18 +298,18 @@ where
 it should return [x, y, f, a, b] (remember, order important).
 
 \begin{code}
-collectLocalBinders :: HsLocalBinds name -> [Located name]
+collectLocalBinders :: HsLocalBindsLR idL idR -> [Located idL]
 collectLocalBinders (HsValBinds val_binds) = collectHsValBinders val_binds
 collectLocalBinders (HsIPBinds _)   = []
 collectLocalBinders EmptyLocalBinds = []
 
-collectHsValBinders :: HsValBinds name -> [Located name]
+collectHsValBinders :: HsValBindsLR idL idR -> [Located idL]
 collectHsValBinders (ValBindsIn binds sigs)  = collectHsBindLocatedBinders binds
 collectHsValBinders (ValBindsOut binds sigs) = foldr collect_one [] binds
   where
    collect_one (_,binds) acc = foldrBag (collectAcc . unLoc) acc binds
 
-collectAcc :: HsBind name -> [Located name] -> [Located name]
+collectAcc :: HsBindLR idL idR -> [Located idL] -> [Located idL]
 collectAcc (PatBind { pat_lhs = p }) acc = collectLocatedPatBinders p ++ acc
 collectAcc (FunBind { fun_id = f })  acc    = f : acc
 collectAcc (VarBind { var_id = f })  acc    = noLoc f : acc
@@ -304,10 +320,10 @@ collectAcc (AbsBinds { abs_exports = dbinds, abs_binds = binds }) acc
 	-- The only time we collect binders from a typechecked 
 	-- binding (hence see AbsBinds) is in zonking in TcHsSyn
 
-collectHsBindBinders :: LHsBinds name -> [name]
+collectHsBindBinders :: LHsBindsLR idL idR -> [idL]
 collectHsBindBinders binds = map unLoc (collectHsBindLocatedBinders binds)
 
-collectHsBindLocatedBinders :: LHsBinds name -> [Located name]
+collectHsBindLocatedBinders :: LHsBindsLR idL idR -> [Located idL]
 collectHsBindLocatedBinders binds = foldrBag (collectAcc . unLoc) [] binds
 \end{code}
 
@@ -319,16 +335,16 @@ collectHsBindLocatedBinders binds = foldrBag (collectAcc . unLoc) [] binds
 %************************************************************************
 
 \begin{code}
-collectLStmtsBinders :: OutputableBndr id => [LStmt id] -> [Located id]
+collectLStmtsBinders :: [LStmtLR idL idR] -> [Located idL]
 collectLStmtsBinders = concatMap collectLStmtBinders
 
-collectStmtsBinders :: OutputableBndr id => [Stmt id] -> [Located id]
+collectStmtsBinders :: [StmtLR idL idR] -> [Located idL]
 collectStmtsBinders = concatMap collectStmtBinders
 
-collectLStmtBinders :: OutputableBndr id => LStmt id -> [Located id]
+collectLStmtBinders :: LStmtLR idL idR -> [Located idL]
 collectLStmtBinders = collectStmtBinders . unLoc
 
-collectStmtBinders :: OutputableBndr id => Stmt id -> [Located id]
+collectStmtBinders :: StmtLR idL idR -> [Located idL]
   -- Id Binders for a Stmt... [but what about pattern-sig type vars]?
 collectStmtBinders (BindStmt pat _ _ _) = collectLocatedPatBinders pat
 collectStmtBinders (LetStmt binds)      = collectLocalBinders binds
@@ -336,7 +352,6 @@ collectStmtBinders (ExprStmt _ _ _)     = []
 collectStmtBinders (ParStmt xs)         = collectLStmtsBinders
                                         $ concatMap fst xs
 collectStmtBinders (RecStmt ss _ _ _ _) = collectLStmtsBinders ss
-collectStmtBinders s                    = pprPanic "collectStmtBinders" (ppr s)
 \end{code}
 
 
@@ -377,6 +392,7 @@ collectl (L l pat) bndrs
     go (LazyPat pat)     	  = collectl pat bndrs
     go (BangPat pat)     	  = collectl pat bndrs
     go (AsPat a pat)     	  = a : collectl pat bndrs
+    go (ViewPat exp pat _)     = collectl pat bndrs
     go (ParPat  pat)     	  = collectl pat bndrs
 				  
     go (ListPat pats _)    	  = foldr collectl bndrs pats
@@ -387,7 +403,7 @@ collectl (L l pat) bndrs
     go (ConPatOut {pat_args=ps})  = foldr collectl bndrs (hsConPatArgs ps)
 	-- See Note [Dictionary binders in ConPatOut]
     go (LitPat _)	      	  = bndrs
-    go (NPat _ _ _ _)		  = bndrs
+    go (NPat _ _ _)		  = bndrs
     go (NPlusKPat n _ _ _)        = n : bndrs
  				  
     go (SigPatIn pat _)	 	  = collectl pat bndrs
@@ -406,6 +422,22 @@ 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.)
 
+Desugaring of arrow case expressions needs these bindings (see DsArrows
+and arrowcase1), but SPJ (Jan 2007) says it's safer for it to use its
+own pat-binder-collector:
+
+Here's the problem.  Consider
+
+data T a where
+   C :: Num a => a -> Int -> T a
+
+f ~(C (n+1) m) = (n,m)
+
+Here, the pattern (C (n+1)) binds a hidden dictionary (d::Num a),
+and *also* uses that dictionary to match the (n+1) pattern.  Yet, the
+variables bound by the lazy pattern are n,m, *not* the dictionary d.
+So in mkSelectorBinds in DsUtils, we want just m,n as the variables bound.
+
 \begin{code}
 collectSigTysFromPats :: [InPat name] -> [LHsType name]
 collectSigTysFromPats pats = foldr collect_lpat [] pats