[project @ 2002-02-15 09:32:47 by simonpj]

Comments only

diff --git a/ghc/compiler/typecheck/TcSimplify.lhs b/ghc/compiler/typecheck/TcSimplify.lhs
index 5ef2132..d0993ba 100644 (file)
--- a/ghc/compiler/typecheck/TcSimplify.lhs
+++ b/ghc/compiler/typecheck/TcSimplify.lhs
@@ -670,9 +670,14 @@ tcSimplifyCheck
 
 -- tcSimplifyCheck is used when checking expression type signatures,
 -- class decls, instance decls etc.
--- Note that we psss isFree (not isFreeAndInheritable) to tcSimplCheck
+--
+-- NB: we psss isFree (not isFreeAndInheritable) to tcSimplCheck
 -- It's important that we can float out non-inheritable predicates
 -- Example:            (?x :: Int) is ok!
+--
+-- NB: tcSimplifyCheck does not consult the
+--     global type variables in the environment; so you don't
+--     need to worry about setting them before calling tcSimplifyCheck
 tcSimplifyCheck doc qtvs givens wanted_lie
   = tcSimplCheck doc get_qtvs
                 givens wanted_lie      `thenTc` \ (qtvs', frees, binds) ->