Map.hs

-- Author:     Andy Stewart <lazycat.manatee@gmail.com>
-- Maintainer: Andy Stewart <lazycat.manatee@gmail.com>
-- 
-- Copyright (C) 2010 Andy Stewart, all rights reserved.
-- 
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- any later version.
-- 
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
-- 
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

module Manatee.Toolkit.General.Map where

import Data.Map (Map)

import qualified Data.Map as M

-- | Find min match one.
findMinMatch :: Ord k => Map k a -> (k -> a -> Bool) -> Maybe (k, a)
findMinMatch map fun = match
    where filterMap = M.filterWithKey fun map
          match     = if M.null filterMap
                         then Nothing
                         else Just $ M.findMin filterMap