Give stateless a type signature.

[matthijs/master-project/cλash.git] / Adders.hs

diff --git a/Adders.hs b/Adders.hs
index b09b98fdc4b43823fc13325f9887a7ea7f6cf260..ce261668e48eb7a9afd5a8e05ddb4bd31f65edf0 100644 (file)
--- a/Adders.hs
+++ b/Adders.hs
@@ -7,6 +7,7 @@ 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))
@@ -31,6 +32,13 @@ 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
+
 -- Combinatoric stateless no-carry adder
 -- A -> B -> S
 no_carry_adder :: (Bit, Bit) -> Bit