From: simonpj@microsoft.com <unknown>
Date: Tue, 22 Apr 2008 11:52:38 +0000 (+0000)
Subject: Minor bug in SpecConstr
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=207151a384d187c29baa5bf3ec2405c27d58c1df;p=ghc-hetmet.git

Minor bug in SpecConstr

In SpecConstr.isValue, we recorded a ConVal for a big-lambda,
which seems wrong. I came across this when implementing System IF.
The code now reads:

  isValue env (Lam b e)
    | isTyVar b = case isValue env e of
  		    Just _  -> Just LambdaVal	-- NB!
  		    Nothing -> Nothing
    | otherwise = Just LambdaVal
---

diff --git a/compiler/specialise/SpecConstr.lhs b/compiler/specialise/SpecConstr.lhs
index c9b5998..1897e1a 100644
--- a/compiler/specialise/SpecConstr.lhs
+++ b/compiler/specialise/SpecConstr.lhs
@@ -1320,7 +1320,9 @@ isValue env (Var v)
 	-- as well, for let-bound constructors!
 
 isValue env (Lam b e)
-  | isTyVar b = isValue env e
+  | isTyVar b = case isValue env e of
+		  Just _  -> Just LambdaVal
+		  Nothing -> Nothing
   | otherwise = Just LambdaVal
 
 isValue _env expr	-- Maybe it's a constructor application