X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FdeSugar%2FDsUtils.lhs;h=9d787add263e25e9e29d67c6391bdeb66e244b5f;hb=334a6323edaec65fc22c5d872a7050a5266ec470;hp=6d2b2c6584135a37ffc769e43d094fcf671c0003;hpb=17b297d97d327620ed6bfab942f8992b2446f1bf;p=ghc-hetmet.git

diff --git a/compiler/deSugar/DsUtils.lhs b/compiler/deSugar/DsUtils.lhs
index 6d2b2c6..9d787ad 100644
--- a/compiler/deSugar/DsUtils.lhs
+++ b/compiler/deSugar/DsUtils.lhs
@@ -8,11 +8,11 @@ Utilities for desugaring
 This module exports some utility functions of no great interest.
 
 \begin{code}
-{-# OPTIONS_GHC -w #-}
+{-# 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/WorkingConventions#Warnings
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
 module DsUtils (
@@ -25,7 +25,7 @@ module DsUtils (
 	cantFailMatchResult, alwaysFailMatchResult,
 	extractMatchResult, combineMatchResults, 
 	adjustMatchResult,  adjustMatchResultDs,
-	mkCoLetMatchResult, mkGuardedMatchResult, 
+	mkCoLetMatchResult, mkViewMatchResult, mkGuardedMatchResult, 
 	matchCanFail, mkEvalMatchResult,
 	mkCoPrimCaseMatchResult, mkCoAlgCaseMatchResult,
 	wrapBind, wrapBinds,
@@ -319,6 +319,12 @@ seqVar var body = Case (Var var) var (exprType body)
 mkCoLetMatchResult :: CoreBind -> MatchResult -> MatchResult
 mkCoLetMatchResult bind = adjustMatchResult (mkDsLet bind)
 
+-- (mkViewMatchResult var' viewExpr var mr) makes the expression
+-- let var' = viewExpr var in mr
+mkViewMatchResult :: Id -> CoreExpr -> Id -> MatchResult -> MatchResult
+mkViewMatchResult var' viewExpr var = 
+    adjustMatchResult (mkDsLet (NonRec var' (mkDsApp viewExpr (Var var))))
+
 mkEvalMatchResult :: Id -> Type -> MatchResult -> MatchResult
 mkEvalMatchResult var ty
   = adjustMatchResult (\e -> Case (Var var) var ty [(DEFAULT, [], e)])