Reactogon/Translator/Auxiliary.hs

   1 module Auxiliary ( breakMap
   2                  )where
   3
   4 import Control.Arrow
   5 import Data.Map (Map)
   6 import qualified Data.Map as M
   7
   8 dupl :: (Arrow a) => a b c -> a (b,b) (c,c)
   9 dupl f = f *** f
  10
  11 breakMap :: (Ord k) => k -> Map k a -> (Map k a, Map k a)
  12 breakMap k m = (smaller, larger')
  13   where (smaller, maybeValue, larger) = M.splitLookup k m
  14         larger' = maybe larger (\v -> M.insert k v larger) maybeValue