Language/LOL/Symantic/Trans/Common.hs

   1 {-# LANGUAGE MultiParamTypeClasses #-}
   2 module Language.LOL.Symantic.Trans.Common where
   3
   4 -- |
   5 -- * 'trans_lift' is generally not /surjective/
   6 -- * 'trans_apply' is not /injective/
   7 -- * 'trans_apply' . 'trans_lift' == 'id'
   8 -- * 'trans_lift' . 'trans_apply' /= 'id'
   9 class Trans trans repr where
  10         trans_lift  :: repr a -> trans repr a
  11         trans_apply :: trans repr a -> repr a
  12
  13         trans_map1 :: (repr a -> repr b) -> (trans repr a -> trans repr b)
  14         trans_map1 f = trans_lift . f . trans_apply
  15
  16         trans_map2
  17          :: (repr a -> repr b -> repr c)
  18          -> (trans repr a -> trans repr b -> trans repr c)
  19         trans_map2 f e1 e2 = trans_lift (f (trans_apply e1) (trans_apply e2))