X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FUnify.lhs;h=2f2cfb892734c4c31b990705989bd2916492f72f;hb=5289f5d85610f71625a439747a09384876655eb5;hp=de5ac49c2dae762788fda1596c76415eadaa3748;hpb=91ab6902b7f1e553be96b2301e9ae6a979b5fc48;p=ghc-hetmet.git

diff --git a/compiler/types/Unify.lhs b/compiler/types/Unify.lhs
index de5ac49..2f2cfb8 100644
--- a/compiler/types/Unify.lhs
+++ b/compiler/types/Unify.lhs
@@ -380,7 +380,7 @@ dataConCannotMatch tys con
 \begin{code}
 tcUnifyTys :: (TyVar -> BindFlag)
 	   -> [Type] -> [Type]
-	   -> Maybe TvSubst	-- A regular one-shot substitution
+	   -> Maybe TvSubst	-- A regular one-shot (idempotent) substitution
 -- The two types may have common type variables, and indeed do so in the
 -- second call to tcUnifyTys in FunDeps.checkClsFD
 --