[project @ 2005-04-04 11:55:11 by simonpj]

[ghc-hetmet.git] / ghc / compiler / deSugar / DsGRHSs.lhs

diff --git a/ghc/compiler/deSugar/DsGRHSs.lhs b/ghc/compiler/deSugar/DsGRHSs.lhs
index 664e2eb..4294d31 100644 (file)
--- a/ghc/compiler/deSugar/DsGRHSs.lhs
+++ b/ghc/compiler/deSugar/DsGRHSs.lhs
@@ -12,7 +12,7 @@ import {-# SOURCE #-} DsExpr  ( dsLExpr, dsLet )
 import {-# SOURCE #-} Match   ( matchSinglePat )
 
 import HsSyn           ( Stmt(..), HsExpr(..), GRHSs(..), GRHS(..), 
-                         HsMatchContext(..), Pat(..) )
+                         LHsExpr, HsMatchContext(..), Pat(..) )
 import CoreSyn         ( CoreExpr )
 import Var             ( Id )
 import Type            ( Type )
@@ -64,8 +64,9 @@ dsGRHSs kind pats (GRHSs grhss binds) rhs_ty
     in
     returnDs match_result2
 
-dsGRHS kind pats rhs_ty (L loc (GRHS guard))
-  = matchGuard (map unLoc guard) (DsMatchContext kind pats loc) rhs_ty
+dsGRHS kind pats rhs_ty (L loc (GRHS guards rhs))
+  = matchGuard (map unLoc guards) (DsMatchContext kind pats loc)
+              rhs rhs_ty
 \end{code}
 
 
@@ -78,41 +79,42 @@ dsGRHS kind pats rhs_ty (L loc (GRHS guard))
 \begin{code}
 matchGuard :: [Stmt Id]        -- Guard
            -> DsMatchContext   -- Context
+          -> LHsExpr Id        -- RHS
           -> Type              -- Type of RHS of guard
           -> DsM MatchResult
 
 -- See comments with HsExpr.Stmt re what an ExprStmt means
 -- Here we must be in a guard context (not do-expression, nor list-comp)       
 
-matchGuard [ResultStmt expr] ctx rhs_ty
-  = do { core_expr <- dsLExpr expr
-       ; return (cantFailMatchResult core_expr) }
+matchGuard [] ctx rhs rhs_ty
+  = do { core_rhs <- dsLExpr rhs
+       ; return (cantFailMatchResult core_rhs) }
 
        -- ExprStmts must be guards
        -- Turn an "otherwise" guard is a no-op
-matchGuard (ExprStmt (L _ (HsVar v)) _ : stmts) ctx rhs_ty
+matchGuard (ExprStmt (L _ (HsVar v)) _ _ : stmts) ctx rhs rhs_ty
   |  v `hasKey` otherwiseIdKey
   || v `hasKey` getUnique trueDataConId        
        -- trueDataConId doesn't have the same 
        -- unique as trueDataCon
-  = matchGuard stmts ctx rhs_ty
+  = matchGuard stmts ctx rhs rhs_ty
 
-matchGuard (ExprStmt expr _ : stmts) ctx rhs_ty
-  = matchGuard stmts ctx rhs_ty        `thenDs` \ match_result ->
-    dsLExpr expr               `thenDs` \ pred_expr ->
+matchGuard (ExprStmt expr _ _ : stmts) ctx rhs rhs_ty
+  = matchGuard stmts ctx rhs rhs_ty    `thenDs` \ match_result ->
+    dsLExpr expr                       `thenDs` \ pred_expr ->
     returnDs (mkGuardedMatchResult pred_expr match_result)
 
-matchGuard (LetStmt binds : stmts) ctx rhs_ty
-  = matchGuard stmts ctx rhs_ty        `thenDs` \ match_result ->
+matchGuard (LetStmt binds : stmts) ctx rhs rhs_ty
+  = matchGuard stmts ctx rhs rhs_ty    `thenDs` \ match_result ->
     returnDs (adjustMatchResultDs (dsLet binds) match_result)
        -- NB the dsLet occurs inside the match_result
        -- Reason: dsLet takes the body expression as its argument
        --         so we can't desugar the bindings without the
        --         body expression in hand
 
-matchGuard (BindStmt pat bind_rhs : stmts) ctx rhs_ty
-  = matchGuard stmts ctx rhs_ty        `thenDs` \ match_result ->
-    dsLExpr bind_rhs           `thenDs` \ core_rhs ->
+matchGuard (BindStmt pat bind_rhs _ _ : stmts) ctx rhs rhs_ty
+  = matchGuard stmts ctx rhs rhs_ty    `thenDs` \ match_result ->
+    dsLExpr bind_rhs                   `thenDs` \ core_rhs ->
     matchSinglePat core_rhs ctx pat rhs_ty match_result
 \end{code}