X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FsimplCore%2FSimplEnv.lhs;h=c9fb4fbb8ba23d5d9471a535c0498c71fe0609e1;hb=59264221c24a17e7c8ecde3e289882b9620bd5a8;hp=f9e048430b81c598661ea8c093fbfecc423f3e2c;hpb=7a327c1297615a9498e7117a0017b09ff2458d53;p=ghc-hetmet.git

diff --git a/compiler/simplCore/SimplEnv.lhs b/compiler/simplCore/SimplEnv.lhs
index f9e0484..c9fb4fb 100644
--- a/compiler/simplCore/SimplEnv.lhs
+++ b/compiler/simplCore/SimplEnv.lhs
@@ -21,7 +21,7 @@ module SimplEnv (
 	setEnclosingCC, getEnclosingCC,
 
 	-- Environments
-	SimplEnv(..), 	-- Temp not abstract
+	SimplEnv(..), pprSimplEnv,	-- Temp not abstract
 	mkSimplEnv, extendIdSubst, SimplEnv.extendTvSubst, 
 	zapSubstEnv, setSubstEnv, 
 	getInScope, setInScope, setInScopeSet, modifyInScope, addNewInScopeIds,
@@ -129,7 +129,14 @@ data SimplEnv
 
     }
 
+pprSimplEnv :: SimplEnv -> SDoc
+-- Used for debugging; selective
+pprSimplEnv env
+  = vcat [ptext SLIT("TvSubst:") <+> ppr (seTvSubst env),
+ 	  ptext SLIT("IdSubst:") <+> ppr (seIdSubst env) ]
+
 type SimplIdSubst = IdEnv SimplSR	-- IdId |--> OutExpr
+	-- See Note [Extending the Subst] in CoreSubst
 
 data SimplSR
   = DoneEx OutExpr		-- Completed term
@@ -137,15 +144,16 @@ data SimplSR
   | ContEx TvSubstEnv	 	-- A suspended substitution
 	   SimplIdSubst
 	   InExpr 	 
+
 instance Outputable SimplSR where
   ppr (DoneEx e) = ptext SLIT("DoneEx") <+> ppr e
   ppr (DoneId v) = ptext SLIT("DoneId") <+> ppr v
   ppr (ContEx tv id e) = vcat [ptext SLIT("ContEx") <+> ppr e {-,
 				ppr (filter_env tv), ppr (filter_env id) -}]
-	where
-	  fvs = exprFreeVars e
-	  filter_env env = filterVarEnv_Directly keep env
-	  keep uniq _ = uniq `elemUFM_Directly` fvs
+	-- where
+	-- fvs = exprFreeVars e
+	-- filter_env env = filterVarEnv_Directly keep env
+	-- keep uniq _ = uniq `elemUFM_Directly` fvs
 \end{code}
 
 
@@ -531,6 +539,8 @@ substIdBndr :: SimplEnv -> Id 	-- Substitition and Id to transform
 --	* The substitution extended with a DoneId if unique changed
 --	  In this case, the var in the DoneId is the same as the
 --	  var returned
+--
+-- Exactly like CoreSubst.substIdBndr, except that the type of id_subst differs
 
 substIdBndr env@(SimplEnv { seInScope = in_scope, seIdSubst = id_subst})
 	    old_id
@@ -549,6 +559,7 @@ substIdBndr env@(SimplEnv { seInScope = in_scope, seIdSubst = id_subst})
 
 	-- Extend the substitution if the unique has changed
 	-- See the notes with substTyVarBndr for the delSubstEnv
+	-- Also see Note [Extending the Subst] in CoreSubst
     new_subst | new_id /= old_id
 	      = extendVarEnv id_subst old_id (DoneId new_id)
 	      | otherwise