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{-
(c) The University of Glasgow 2006
(c) The GRASP/AQUA Project, Glasgow University, 1998
-}
{-# LANGUAGE CPP #-}
module NameSet (
-- * Names set type
NameSet,
-- ** Manipulating these sets
emptyNameSet, unitNameSet, mkNameSet, unionNameSet, unionNameSets,
minusNameSet, elemNameSet, extendNameSet, extendNameSetList,
delFromNameSet, delListFromNameSet, isEmptyNameSet, filterNameSet,
intersectsNameSet, intersectNameSet,
nameSetAny, nameSetAll, nameSetElemsStable,
-- * Free variables
FreeVars,
-- ** Manipulating sets of free variables
isEmptyFVs, emptyFVs, plusFVs, plusFV,
mkFVs, addOneFV, unitFV, delFV, delFVs,
intersectFVs,
-- * Defs and uses
Defs, Uses, DefUse, DefUses,
-- ** Manipulating defs and uses
emptyDUs, usesOnly, mkDUs, plusDU,
findUses, duDefs, duUses, allUses
) where
#include "HsVersions.h"
import GhcPrelude
import Name
import OrdList
import UniqSet
import Data.List (sortBy)
{-
************************************************************************
* *
\subsection[Sets of names}
* *
************************************************************************
-}
type NameSet = UniqSet Name
emptyNameSet :: NameSet
unitNameSet :: Name -> NameSet
extendNameSetList :: NameSet -> [Name] -> NameSet
extendNameSet :: NameSet -> Name -> NameSet
mkNameSet :: [Name] -> NameSet
unionNameSet :: NameSet -> NameSet -> NameSet
unionNameSets :: [NameSet] -> NameSet
minusNameSet :: NameSet -> NameSet -> NameSet
elemNameSet :: Name -> NameSet -> Bool
isEmptyNameSet :: NameSet -> Bool
delFromNameSet :: NameSet -> Name -> NameSet
delListFromNameSet :: NameSet -> [Name] -> NameSet
filterNameSet :: (Name -> Bool) -> NameSet -> NameSet
intersectNameSet :: NameSet -> NameSet -> NameSet
intersectsNameSet :: NameSet -> NameSet -> Bool
-- ^ True if there is a non-empty intersection.
-- @s1 `intersectsNameSet` s2@ doesn't compute @s2@ if @s1@ is empty
isEmptyNameSet = isEmptyUniqSet
emptyNameSet = emptyUniqSet
unitNameSet = unitUniqSet
mkNameSet = mkUniqSet
extendNameSetList = addListToUniqSet
extendNameSet = addOneToUniqSet
unionNameSet = unionUniqSets
unionNameSets = unionManyUniqSets
minusNameSet = minusUniqSet
elemNameSet = elementOfUniqSet
delFromNameSet = delOneFromUniqSet
filterNameSet = filterUniqSet
intersectNameSet = intersectUniqSets
delListFromNameSet set ns = foldl' delFromNameSet set ns
intersectsNameSet s1 s2 = not (isEmptyNameSet (s1 `intersectNameSet` s2))
nameSetAny :: (Name -> Bool) -> NameSet -> Bool
nameSetAny = uniqSetAny
nameSetAll :: (Name -> Bool) -> NameSet -> Bool
nameSetAll = uniqSetAll
-- | Get the elements of a NameSet with some stable ordering.
-- This only works for Names that originate in the source code or have been
-- tidied.
-- See Note [Deterministic UniqFM] to learn about nondeterminism
nameSetElemsStable :: NameSet -> [Name]
nameSetElemsStable ns =
sortBy stableNameCmp $ nonDetEltsUniqSet ns
-- It's OK to use nonDetEltsUniqSet here because we immediately sort
-- with stableNameCmp
{-
************************************************************************
* *
\subsection{Free variables}
* *
************************************************************************
These synonyms are useful when we are thinking of free variables
-}
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
intersectFVs :: FreeVars -> FreeVars -> FreeVars
isEmptyFVs :: NameSet -> Bool
isEmptyFVs = isEmptyNameSet
emptyFVs = emptyNameSet
plusFVs = unionNameSets
plusFV = unionNameSet
mkFVs = mkNameSet
addOneFV = extendNameSet
unitFV = unitNameSet
delFV n s = delFromNameSet s n
delFVs ns s = delListFromNameSet s ns
intersectFVs = intersectNameSet
{-
************************************************************************
* *
Defs and uses
* *
************************************************************************
-}
-- | A set of names that are defined somewhere
type Defs = NameSet
-- | A set of names that are used somewhere
type Uses = NameSet
-- | @(Just ds, us) =>@ The use of any member of the @ds@
-- implies that all the @us@ are used too.
-- Also, @us@ may mention @ds@.
--
-- @Nothing =>@ Nothing is defined in this group, but
-- nevertheless all the uses are essential.
-- Used for instance declarations, for example
type DefUse = (Maybe Defs, Uses)
-- | A number of 'DefUse's in dependency order: earlier 'Defs' scope over later 'Uses'
-- In a single (def, use) pair, the defs also scope over the uses
type DefUses = OrdList DefUse
emptyDUs :: DefUses
emptyDUs = nilOL
usesOnly :: Uses -> DefUses
usesOnly uses = unitOL (Nothing, uses)
mkDUs :: [(Defs,Uses)] -> DefUses
mkDUs pairs = toOL [(Just defs, uses) | (defs,uses) <- pairs]
plusDU :: DefUses -> DefUses -> DefUses
plusDU = appOL
duDefs :: DefUses -> Defs
duDefs dus = foldr get emptyNameSet dus
where
get (Nothing, _u1) d2 = d2
get (Just d1, _u1) d2 = d1 `unionNameSet` d2
allUses :: DefUses -> Uses
-- ^ Just like 'duUses', but 'Defs' are not eliminated from the 'Uses' returned
allUses dus = foldr get emptyNameSet dus
where
get (_d1, u1) u2 = u1 `unionNameSet` u2
duUses :: DefUses -> Uses
-- ^ Collect all 'Uses', regardless of whether the group is itself used,
-- but remove 'Defs' on the way
duUses dus = foldr get emptyNameSet dus
where
get (Nothing, rhs_uses) uses = rhs_uses `unionNameSet` uses
get (Just defs, rhs_uses) uses = (rhs_uses `unionNameSet` uses)
`minusNameSet` defs
findUses :: DefUses -> Uses -> Uses
-- ^ Given some 'DefUses' and some 'Uses', find all the uses, transitively.
-- The result is a superset of the input 'Uses'; and includes things defined
-- in the input 'DefUses' (but only if they are used)
findUses dus uses
= foldr get uses dus
where
get (Nothing, rhs_uses) uses
= rhs_uses `unionNameSet` uses
get (Just defs, rhs_uses) uses
| defs `intersectsNameSet` uses -- Used
|| nameSetAny (startsWithUnderscore . nameOccName) defs
-- At least one starts with an "_",
-- so treat the group as used
= rhs_uses `unionNameSet` uses
| otherwise -- No def is used
= uses
|
