Util.hs

   1 -- This file is part of Intricacy
   2 -- Copyright (C) 2013 Martin Bays <mbays@sdf.org>
   3 --
   4 -- This program is free software: you can redistribute it and/or modify
   5 -- it under the terms of version 3 of the GNU General Public License as
   6 -- published by the Free Software Foundation, or any later version.
   7 --
   8 -- You should have received a copy of the GNU General Public License
   9 -- along with this program.  If not, see http://www.gnu.org/licenses/.
  10
  11 module Util where
  12 import qualified Data.Vector as Vector
  13 import Data.Vector (Vector)
  14 import Control.Monad
  15 import Control.Monad.Trans.Maybe
  16
  17 enumVec :: Vector a -> [(Int,a)]
  18 enumVec = Vector.toList . Vector.indexed
  19
  20 liftMaybe :: Monad m => Maybe a -> MaybeT m a
  21 liftMaybe = MaybeT . return
  22
  23 -- nice tip from one joeyh:
  24 whenM,unlessM,(>>?),(>>!) :: Monad m => m Bool -> m () -> m ()
  25 whenM c a = c >>= flip when a
  26 unlessM c a = c >>= flip unless a
  27 (>>?) = whenM
  28 (>>!) = unlessM
  29 -- same precedence as ($), allowing e.g. foo bar >>! error $ "failed " ++ meep
  30 infixr 0 >>?
  31 infixr 0 >>!
  32
  33 -- |fi: just a straight abbreviation for fromIntegral
  34 fi :: (Integral a, Num b) => a -> b
  35 fi = fromIntegral