Adder.hs

module HarfAdder where
import Data.Bits
import Data.Word
import Control.Applicative

harfAdder True  True   = (False,True)
harfAdder True  False  = (True, False)
harfAdder False True   = (True, False)
harfAdder False False  = (False,False)

fullAdder  = 
     (\ a b c -> let (a',b') = harfAdder a b 
                  in let (a'',b'') = harfAdder a' c in (a'' , b'||b''))

phi :: (Bool,[Bool]) -> (Bool,Bool) -> (Bool,[Bool])
phi (c,xs) (a,b) =  let (s,c') =  fullAdder a b c in (c',s:xs)


plus xs ys = let (c, ss) = g xs ys in c:ss
  where 
        g = (f .) . aux
        f = foldl phi (False,[])
        aux :: [Bool] -> [Bool] -> [(Bool,Bool)]
        aux = zipWith (,)

Haskellでbit加算器
Boolをbitにみたててある