basicTypes/NameEnv.hs

    {-
    (c) The University of Glasgow 2006
    (c) The GRASP/AQUA Project, Glasgow University, 1992-1998

    \section[NameEnv]{@NameEnv@: name environments}
    -}

    {-# LANGUAGE CPP #-}
    module NameEnv (
            -- * Var, Id and TyVar environments (maps)
            NameEnv,

            -- ** Manipulating these environments
            mkNameEnv,
            emptyNameEnv, isEmptyNameEnv,
            unitNameEnv, nameEnvElts,
            extendNameEnv_C, extendNameEnv_Acc, extendNameEnv,
            extendNameEnvList, extendNameEnvList_C,
            filterNameEnv, anyNameEnv,
            plusNameEnv, plusNameEnv_C, alterNameEnv,
            lookupNameEnv, lookupNameEnv_NF, delFromNameEnv, delListFromNameEnv,
            elemNameEnv, mapNameEnv, disjointNameEnv,

            DNameEnv,

            emptyDNameEnv,
            lookupDNameEnv,
            mapDNameEnv,
            alterDNameEnv,
            -- ** Dependency analysis
            depAnal
        ) where

    #include "HsVersions.h"

    import Digraph
    import Name
    import UniqFM
    import UniqDFM
    import Maybes

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Name environment}
    *                                                                      *
    ************************************************************************
    -}

    {-
    Note [depAnal determinism]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~
    depAnal is deterministic provided it gets the nodes in a deterministic order.
    The order of lists that get_defs and get_uses return doesn't matter, as these
    are only used to construct the edges, and stronglyConnCompFromEdgedVertices is
    deterministic even when the edges are not in deterministic order as explained
    in Note [Deterministic SCC] in Digraph.
    -}

    depAnal :: (node -> [Name])      -- Defs
            -> (node -> [Name])      -- Uses
            -> [node]
            -> [SCC node]
    -- Peform dependency analysis on a group of definitions,
    -- where each definition may define more than one Name
    --
    -- The get_defs and get_uses functions are called only once per node
    depAnal get_defs get_uses nodes
      = stronglyConnCompFromEdgedVerticesUniq (map mk_node keyed_nodes)
      where
        keyed_nodes = nodes `zip` [(1::Int)..]
        mk_node (node, key) = (node, key, mapMaybe (lookupNameEnv key_map) (get_uses node))

        key_map :: NameEnv Int   -- Maps a Name to the key of the decl that defines it
        key_map = mkNameEnv [(name,key) | (node, key) <- keyed_nodes, name <- get_defs node]

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Name environment}
    *                                                                      *
    ************************************************************************
    -}

    -- | Name Environment
    type NameEnv a = UniqFM a       -- Domain is Name

    emptyNameEnv       :: NameEnv a
    isEmptyNameEnv     :: NameEnv a -> Bool
    mkNameEnv          :: [(Name,a)] -> NameEnv a
    nameEnvElts        :: NameEnv a -> [a]
    alterNameEnv       :: (Maybe a-> Maybe a) -> NameEnv a -> Name -> NameEnv a
    extendNameEnv_C    :: (a->a->a) -> NameEnv a -> Name -> a -> NameEnv a
    extendNameEnv_Acc  :: (a->b->b) -> (a->b) -> NameEnv b -> Name -> a -> NameEnv b
    extendNameEnv      :: NameEnv a -> Name -> a -> NameEnv a
    plusNameEnv        :: NameEnv a -> NameEnv a -> NameEnv a
    plusNameEnv_C      :: (a->a->a) -> NameEnv a -> NameEnv a -> NameEnv a
    extendNameEnvList  :: NameEnv a -> [(Name,a)] -> NameEnv a
    extendNameEnvList_C :: (a->a->a) -> NameEnv a -> [(Name,a)] -> NameEnv a
    delFromNameEnv     :: NameEnv a -> Name -> NameEnv a
    delListFromNameEnv :: NameEnv a -> [Name] -> NameEnv a
    elemNameEnv        :: Name -> NameEnv a -> Bool
    unitNameEnv        :: Name -> a -> NameEnv a
    lookupNameEnv      :: NameEnv a -> Name -> Maybe a
    lookupNameEnv_NF   :: NameEnv a -> Name -> a
    filterNameEnv      :: (elt -> Bool) -> NameEnv elt -> NameEnv elt
    anyNameEnv         :: (elt -> Bool) -> NameEnv elt -> Bool
    mapNameEnv         :: (elt1 -> elt2) -> NameEnv elt1 -> NameEnv elt2
    disjointNameEnv    :: NameEnv a -> NameEnv a -> Bool

    nameEnvElts x         = eltsUFM x
    emptyNameEnv          = emptyUFM
    isEmptyNameEnv        = isNullUFM
    unitNameEnv x y       = unitUFM x y
    extendNameEnv x y z   = addToUFM x y z
    extendNameEnvList x l = addListToUFM x l
    lookupNameEnv x y     = lookupUFM x y
    alterNameEnv          = alterUFM
    mkNameEnv     l       = listToUFM l
    elemNameEnv x y          = elemUFM x y
    plusNameEnv x y          = plusUFM x y
    plusNameEnv_C f x y      = plusUFM_C f x y
    extendNameEnv_C f x y z  = addToUFM_C f x y z
    mapNameEnv f x           = mapUFM f x
    extendNameEnv_Acc x y z a b  = addToUFM_Acc x y z a b
    extendNameEnvList_C x y z = addListToUFM_C x y z
    delFromNameEnv x y      = delFromUFM x y
    delListFromNameEnv x y  = delListFromUFM x y
    filterNameEnv x y       = filterUFM x y
    anyNameEnv f x          = foldUFM ((||) . f) False x
    disjointNameEnv x y     = isNullUFM (intersectUFM x y)

    lookupNameEnv_NF env n = expectJust "lookupNameEnv_NF" (lookupNameEnv env n)

    -- | Deterministic Name Environment
    --
    -- See Note [Deterministic UniqFM] in UniqDFM for explanation why we need
    -- DNameEnv.
    type DNameEnv a = UniqDFM a

    emptyDNameEnv :: DNameEnv a
    emptyDNameEnv = emptyUDFM

    lookupDNameEnv :: DNameEnv a -> Name -> Maybe a
    lookupDNameEnv = lookupUDFM

    mapDNameEnv :: (a -> b) -> DNameEnv a -> DNameEnv b
    mapDNameEnv = mapUDFM

    alterDNameEnv :: (Maybe a -> Maybe a) -> DNameEnv a -> Name -> DNameEnv a
    alterDNameEnv = alterUDFM