cli/Hcompta/Expr/Ord.hs

   1 {-# LANGUAGE NoImplicitPrelude #-}
   2 {-# OPTIONS_GHC -fno-warn-tabs #-}
   3
   4 module Hcompta.Expr.Ord where
   5
   6 import Data.Bool
   7 import Data.Ord (Ord(..))
   8
   9 import Hcompta.Expr.Bool
  10 import Hcompta.Expr.Eq
  11 import Hcompta.Expr.Dup
  12
  13 -- * Class 'Expr_Ord'
  14
  15 class
  16  ( Expr_Bool repr
  17  , Expr_Eq repr
  18  ) => Expr_Ord repr where
  19         lt :: Ord a => repr a -> repr a -> repr Bool
  20
  21         le :: Ord a => repr a -> repr a -> repr Bool
  22         le x y = (x `lt` y) `or` (x `eq` y)
  23
  24         ge :: Ord a => repr a -> repr a -> repr Bool
  25         ge x y = neg (x `lt` y)
  26
  27         gt :: Ord a => repr a -> repr a -> repr Bool
  28         gt x y = neg (x `le` y)
  29
  30 instance -- Expr_Ord Dup
  31  ( Expr_Ord r1
  32  , Expr_Ord r2
  33  ) => Expr_Ord (Dup r1 r2) where
  34         lt (x1 `Dup` x2) (y1 `Dup` y2) = lt x1 y1 `Dup` lt x2 y2
  35         le (x1 `Dup` x2) (y1 `Dup` y2) = le x1 y1 `Dup` le x2 y2
  36         ge (x1 `Dup` x2) (y1 `Dup` y2) = ge x1 y1 `Dup` ge x2 y2
  37         gt (x1 `Dup` x2) (y1 `Dup` y2) = gt x1 y1 `Dup` gt x2 y2