BitWise.hs

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-- Copyright © 2011 National Institute of Aerospace / Galois, Inc.
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-- | Bitwise operators.

{-# LANGUAGE Safe #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}

module Copilot.Language.Operators.BitWise
  ( Bits ((.&.), complement, (.|.))
  , (.^.)
  , (.<<.)
  , (.>>.)
  ) where

import Copilot.Core (Typed, typeOf)
import qualified Copilot.Core as Core
import Copilot.Language.Stream
import qualified Prelude as P
import Data.Bits

instance (Typed a, Bits a) => Bits (Stream a) where
  (.&.)      = Op2 (Core.BwAnd typeOf)
  complement = Op1 (Core.BwNot typeOf)
  (.|.)      = Op2 (Core.BwOr  typeOf)
  xor        = Op2 (Core.BwXor typeOf)
  shiftL     = P.error "shiftL undefined, for left-shifting use .<<."
  shiftR     = P.error "shiftR undefined, for right-shifting use .>>."
  rotate     = P.error "tbd: rotate"
  bitSize    = P.error "tbd: bitSize"
  isSigned   = P.error "tbd: issigned"

-- Avoid redefinition of the Operators.Boolean xor
(.^.) :: Bits a => a -> a -> a
(.^.) = xor

(.<<.), (.>>.) :: (Bits a, Typed a, Typed b, P.Integral b) 
               => Stream a -> Stream b -> Stream a
(.<<.) = Op2 (Core.BwShiftL typeOf typeOf)
(.>>.) = Op2 (Core.BwShiftR typeOf typeOf)