From 9387c8e9a23fd7569ff7f53cd142e7824cbe5e55 Mon Sep 17 00:00:00 2001
From: John Benediktsson <mrjbq7@gmail.com>
Date: Tue, 24 Sep 2013 15:07:47 -0700
Subject: [PATCH] combinators.extras: adding throttle.

---
 extra/combinators/extras/extras.factor | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/extra/combinators/extras/extras.factor b/extra/combinators/extras/extras.factor
index 8c6c281c18..4bb67a5835 100644
--- a/extra/combinators/extras/extras.factor
+++ b/extra/combinators/extras/extras.factor
@@ -2,7 +2,7 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: arrays combinators combinators.smart fry generalizations
 kernel macros math quotations sequences
-sequences.generalizations ;
+sequences.generalizations sequences.private system ;
 IN: combinators.extras
 
 : once ( quot -- ) call ; inline
@@ -42,3 +42,9 @@ MACRO: cleave-array ( quots -- )
 MACRO: smart-plox ( true -- )
     [ inputs [ 1 - [ and ] n*quot ] keep ] keep swap
     '[ _ _ [ _ ndrop f ] smart-if ] ;
+
+: throttle ( quot millis -- quot' )
+    1,000,000 * '[
+        _ nano-count { 0 } 2dup first-unsafe _ + >=
+        [ 0 swap set-nth-unsafe call ] [ 3drop ] if
+    ] ; inline