[project @ 2000-10-25 07:09:52 by simonpj]

[ghc-hetmet.git] / ghc / compiler / basicTypes / NameSet.lhs

diff --git a/ghc/compiler/basicTypes/NameSet.lhs b/ghc/compiler/basicTypes/NameSet.lhs
index e09bfac..ad313f7 100644 (file)
--- a/ghc/compiler/basicTypes/NameSet.lhs
+++ b/ghc/compiler/basicTypes/NameSet.lhs
@@ -9,7 +9,11 @@ module NameSet (
        NameSet,
        emptyNameSet, unitNameSet, mkNameSet, unionNameSets, unionManyNameSets,
        minusNameSet, elemNameSet, nameSetToList, addOneToNameSet, addListToNameSet, 
-       delFromNameSet, delListFromNameSet, isEmptyNameSet, foldNameSet, filterNameSet
+       delFromNameSet, delListFromNameSet, isEmptyNameSet, foldNameSet, filterNameSet,
+       
+       -- Free variables
+       FreeVars, isEmptyFVs, emptyFVs, plusFVs, plusFV, 
+       mkFVs, addOneFV, unitFV, delFV, delFVs
     ) where
 
 #include "HsVersions.h"
@@ -62,3 +66,34 @@ delListFromNameSet set ns = foldl delFromNameSet set ns
 \end{code}
 
 
+%************************************************************************
+%*                                                                     *
+\subsection{Free variables}
+%*                                                                     *
+%************************************************************************
+
+These synonyms are useful when we are thinking of free variables
+
+\begin{code}
+type FreeVars  = NameSet
+
+plusFV   :: FreeVars -> FreeVars -> FreeVars
+addOneFV :: FreeVars -> Name -> FreeVars
+unitFV   :: Name -> FreeVars
+emptyFVs :: FreeVars
+plusFVs  :: [FreeVars] -> FreeVars
+mkFVs   :: [Name] -> FreeVars
+delFV    :: Name -> FreeVars -> FreeVars
+delFVs   :: [Name] -> FreeVars -> FreeVars
+
+isEmptyFVs  = isEmptyNameSet
+emptyFVs    = emptyNameSet
+plusFVs     = unionManyNameSets
+plusFV      = unionNameSets
+mkFVs      = mkNameSet
+addOneFV    = addOneToNameSet
+unitFV      = unitNameSet
+delFV n s   = delFromNameSet s n
+delFVs ns s = delListFromNameSet s ns
+\end{code}
+