-- Generic utility functions
module Util where

import Data.Array

{-# SPECIALIZE lookupA :: Array (Int, Int) e -> e -> (Int, Int) -> e #-}

-- Index an array, but use a default value if the index is out of bounds.
lookupA :: (Ix i) => Array i e -> e -> i -> e
lookupA a def i =
  if inRange (bounds a) i
    then a ! i
    else def