-module Adders (main, no_carry_adder) where
+module Adders where
import Bits
import Language.Haskell.Syntax
b = [Low, Low, Low, High]
(s, c) = f (a, b)
--- Combinatoric no-carry adder
+-- Not really an adder, but this is nice minimal hardware description
+wire :: Bit -> Bit
+wire a = a
+
+-- Combinatoric stateless no-carry adder
-- A -> B -> S
no_carry_adder :: (Bit, Bit) -> Bit
no_carry_adder (a, b) = a `hwxor` b
--- Combinatoric (one-bit) full adder
+-- Combinatoric stateless half adder
+-- A -> B -> (S, C)
+half_adder :: (Bit, Bit) -> (Bit, Bit)
+half_adder (a, b) =
+ ( a `hwxor` b, a `hwand` b )
+
+-- Combinatoric stateless full adder
-- (A, B, C) -> (S, C)
full_adder :: (Bit, Bit, Bit) -> (Bit, Bit)
full_adder (a, b, cin) = (s, c)