From 33d96f76234630980a9985c8e76d42c7e544b071 Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Thu, 6 Aug 2015 03:20:10 -0500
Subject: [PATCH] combinators.smart: Add smart combinator that outputs a seq
 and (length-n) more elements.

---
 basis/combinators/smart/smart-tests.factor | 4 ++++
 basis/combinators/smart/smart.factor       | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/basis/combinators/smart/smart-tests.factor b/basis/combinators/smart/smart-tests.factor
index 33523a0154..ffd1e06f62 100644
--- a/basis/combinators/smart/smart-tests.factor
+++ b/basis/combinators/smart/smart-tests.factor
@@ -123,3 +123,7 @@ IN: combinators.smart.tests
         { [ + ] [ + ] }
     } smart-2map-reduce
 ] unit-test
+
+{ { 1 2 3 4 } 5 6 } [ [ 1 2 3 4 5 6 ] 2 output>array-n ] unit-test
+{ { } 5 6 } [ [ 5 6 ] 2 output>array-n ] unit-test
+{ { 1 2 } 3 4 5 6 } [ [ 1 2 3 4 5 6 ] 4 output>array-n ] unit-test
diff --git a/basis/combinators/smart/smart.factor b/basis/combinators/smart/smart.factor
index a620fd4cce..04bb94fde0 100644
--- a/basis/combinators/smart/smart.factor
+++ b/basis/combinators/smart/smart.factor
@@ -67,6 +67,13 @@ M: object infer-known* drop f ;
 : output>array ( quot -- array )
     { } output>sequence ; inline
 
+MACRO: output>sequence-n ( quot exemplar n -- quot )
+    3dup nip [ outputs ] dip - -rot
+    '[ @ [ _ _ nsequence ] _ ndip ] ;
+
+MACRO: output>array-n ( quot n -- array )
+    '[ _ { } _ output>sequence-n ] ;
+
 : cleave>array ( obj quots -- array )
     '[ _ cleave ] output>array ; inline