{- |

Module : $Header$

Copyright : (c) Christian Maeder and Uni Bremen 2003

Licence : similar to LGPL, see HetCATS/LICENCE.txt or LIZENZ.txt

Maintainer : maeder@tzi.de

Stability : provisional

Portability : portable

supply the functions needed by Graph.hs

-}

module Common.Lib.SimpleMap (FiniteMap,

emptyFM,addToFM,

updFM, -- applies function to stored entry

splitFM, -- combines delFrom & lookup

delFromFM,

isEmptyFM,sizeFM,lookupFM,elemFM,

minFM,maxFM,

fmToList

) where

import qualified Common.Lib.Map as Map

type FiniteMap = Map.Map

----------------------------------------------------------------------

-- MAIN FUNCTIONS

----------------------------------------------------------------------

emptyFM :: Ord a => FiniteMap a b

emptyFM = Map.empty

addToFM :: Ord a => FiniteMap a b -> a -> b -> FiniteMap a b

addToFM m a b = Map.insert a b m

updFM :: Ord a => FiniteMap a b -> a -> (b -> b) -> FiniteMap a b

updFM m k f = Map.update (Just . f) k m

delFromFM :: Ord a => FiniteMap a b -> a -> FiniteMap a b

delFromFM = flip Map.delete

isEmptyFM :: Ord a => FiniteMap a b -> Bool

isEmptyFM = Map.isEmpty

sizeFM :: Ord a => FiniteMap a b -> Int

sizeFM = Map.size

lookupFM :: Ord a => FiniteMap a b -> a -> Maybe b

lookupFM = flip Map.lookup

minFM :: Ord a => FiniteMap a b -> Maybe (a,b)

minFM m = if Map.isEmpty m then Nothing

else Just $ Map.findMin m

maxFM :: Ord a => FiniteMap a b -> Maybe (a,b)

maxFM m = if Map.isEmpty m then Nothing

else Just $ Map.findMax m

elemFM :: Ord a => FiniteMap a b -> a -> Bool

elemFM = flip Map.member

splitFM :: Ord a => FiniteMap a b -> a -> Maybe (FiniteMap a b, (a, b))

splitFM m a = case Map.lookup a m of

Nothing -> Nothing

Just b -> Just (Map.delete a m, (a, b))

fmToList :: Ord a => FiniteMap a b -> [(a,b)]

fmToList = Map.toList