X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FcoreSyn%2FCoreSubst.lhs;h=1c81d8859a4fc433980423ccdf9da349fa6266d8;hb=8a2809c29de9f23eba7ca682b48390033a9d40f6;hp=6a2255cf8726fced0948731f492ce452d9d59dd5;hpb=cac2aca1e1874e936f3ef15ca2a81a32c7863750;p=ghc-hetmet.git

diff --git a/compiler/coreSyn/CoreSubst.lhs b/compiler/coreSyn/CoreSubst.lhs
index 6a2255c..1c81d88 100644
--- a/compiler/coreSyn/CoreSubst.lhs
+++ b/compiler/coreSyn/CoreSubst.lhs
@@ -45,6 +45,8 @@ import Outputable
 import PprCore		()		-- Instances
 import Util
 import FastTypes
+
+import Data.List
 \end{code}
 
 
@@ -307,6 +309,7 @@ substRecBndrs subst bndrs
 substIdBndr :: Subst		-- Substitution to use for the IdInfo
 	    -> Subst -> Id 	-- Substitition and Id to transform
 	    -> (Subst, Id)	-- Transformed pair
+				-- NB: unfolding may be zapped
 
 substIdBndr rec_subst subst@(Subst in_scope env tvs) old_id
   = (Subst (in_scope `extendInScopeSet` new_id) new_env tvs, new_id)
@@ -324,6 +327,7 @@ substIdBndr rec_subst subst@(Subst in_scope env tvs) old_id
 	-- rec_subst, when dealing with a mutually-recursive group
     new_id = maybeModifyIdInfo mb_new_info id2
     mb_new_info = substIdInfo rec_subst (idInfo id2)
+	-- NB: unfolding info may be zapped
 
 	-- Extend the substitution if the unique has changed
 	-- See the notes with substTyVarBndr for the delVarEnv