From 6b14071f5ff200186877fb0597b3f7e4f8617907 Mon Sep 17 00:00:00 2001
From: slava <slava@factorcode.org>
Date: Sat, 21 Oct 2006 20:51:38 +0000
Subject: [PATCH] Column virtual sequence

---
 library/collections/virtual-sequences.factor | 19 +++++++++++++++++++
 library/test/collections/sequences.factor    |  7 +++++++
 2 files changed, 26 insertions(+)

diff --git a/library/collections/virtual-sequences.factor b/library/collections/virtual-sequences.factor
index 99c2dadff0..20f54a1b38 100644
--- a/library/collections/virtual-sequences.factor
+++ b/library/collections/virtual-sequences.factor
@@ -65,3 +65,22 @@ M: slice set-nth-unsafe slice@ set-nth-unsafe ;
 M: slice like slice-seq like ;
 
 M: slice thaw slice-seq thaw ;
+
+TUPLE: column col seq ;
+
+: column@ ( m section -- n seq )
+    dup column-col -rot column-seq nth ;
+
+M: column length column-seq length ;
+
+M: column nth column@ nth ;
+
+M: column nth-unsafe column@ nth-unsafe ;
+
+M: column set-nth column@ set-nth ;
+
+M: column set-nth-unsafe column@ set-nth-unsafe ;
+
+M: column like column-seq like ;
+
+M: column thaw column-seq thaw ;
diff --git a/library/test/collections/sequences.factor b/library/test/collections/sequences.factor
index 07d5b4be91..6e8ec7ccf4 100644
--- a/library/test/collections/sequences.factor
+++ b/library/test/collections/sequences.factor
@@ -216,3 +216,10 @@ unit-test
 
 [ V{ 1 2 3 } ]
 [ 3 V{ 1 3 2 } clone [ push-new ] keep ] unit-test
+
+! Columns
+{ { 1 2 3 } { 4 5 6 } { 7 8 9 } } [ clone ] map "seq" set
+
+[ { 1 4 7 } ] [ 0 "seq" get <column> >array ] unit-test
+[ ] [ 1 "seq" get <column> [ sq ] inject ] unit-test
+[ { 4 25 64 } ] [ 1 "seq" get <column> >array ] unit-test