X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=Adders.hs;h=ac93a3366db359f3fc368467fe7280320aece926;hb=0082f01a853476cdcec0e73bacf8c0d4508dbec0;hp=f35021c96fec00580168dc54c2ef4a2f7fe715a9;hpb=ed6bb401ef9c3726084f9477e01228466d34e29c;p=matthijs%2Fmaster-project%2Fc%CE%BBash.git

diff --git a/Adders.hs b/Adders.hs
index f35021c..ac93a33 100644
--- a/Adders.hs
+++ b/Adders.hs
@@ -1,8 +1,14 @@
 module Adders where
 import Bits
+import qualified Sim
 import Language.Haskell.Syntax
 
-main = do show_add exp_adder; show_add rec_adder;
+mainIO f = Sim.simulateIO (Sim.stateless f) ()
+
+-- This function is from Sim.hs, but we redefine it here so it can get inlined
+-- by default.
+stateless :: (i -> o) -> (i -> () -> ((), o))
+stateless f = \i s -> (s, f i)
 
 show_add f = do print ("Sum:   " ++ (displaysigs s)); print ("Carry: " ++ (displaysig c))
   where
@@ -26,6 +32,21 @@ invinv a = hwnot (hwnot a)
 dup :: Bit -> (Bit, Bit)
 dup a = (a, a)
 
+-- Not really an adder either, but a simple stateful example (D-flipflop)
+dff :: Bit -> Bit -> (Bit, Bit)
+dff d s = (s', q)
+  where
+    q = s
+    s' = d
+
+type ShifterState = (Bit, Bit, Bit, Bit)
+shifter :: Bit -> ShifterState -> (ShifterState, Bit)
+shifter a s =
+  (s', o)
+  where
+    s' = (a, b, c, d)
+    (b, c, d, o) = s
+
 -- Combinatoric stateless no-carry adder
 -- A -> B -> S
 no_carry_adder :: (Bit, Bit) -> Bit
@@ -46,6 +67,8 @@ full_adder (a, b, cin) = (s, c)
     (s, c2)  = half_adder(s1, cin)
     c        = c1 `hwor` c2
 
+sfull_adder = stateless full_adder
+
 -- Four bit adder
 -- Explicit version
 -- [a] -> [b] -> ([s], cout)