1 files changed, 42 insertions, 0 deletions
diff --git a/src/primes.ml b/src/primes.ml
new file mode 100644
index 0000000..0911f31
--- /dev/null
+++ b/src/primes.ml
@@ -0,0 +1,42 @@
+module Primes (K : Kahn.S) = struct
+  module K = K
+  module Lib = Kahn.Lib(K)
+  open K
+  open Lib
+
+  let integers nmax (qo : int out_port) : unit process =
+    let rec loop n =
+      if n > nmax then
+        put (-1) qo
+      else
+        (put n qo) >>= (fun () -> loop (n+1))
+    in
+    loop 2
+
+  let filter n (qi : int in_port) (qo : int out_port) : unit process =
+    let rec loop () =
+      (get qi) >>= (fun v ->
+        if v <> -1 then
+          (if v mod n = 0 then return () else put v qo) >>= loop
+        else
+          put v qo)
+    in loop()
+
+  let rec primes (qi : int in_port) : unit process =
+    (get qi) >>= (fun v ->
+      if v <> -1 then begin
+        Format.printf "%d@." v;
+        (delay new_channel ()) >>=
+        (fun (qi2, qo2) -> doco [ filter v qi qo2 ; primes qi2 ])
+      end else return ())
+
+  let main : unit process =
+    (delay new_channel ()) >>=
+    (fun (q_in, q_out) -> doco [ integers 5000 q_out ; primes q_in ])
+
+end
+
+module P = Primes(Kahn.Seq)
+
+let () = P.K.run P.main
+