From 00a8cf0646cba78bcfb86987f62e38b6e43d22eb Mon Sep 17 00:00:00 2001
From: Rene Rivera <grafikrobot@gmail.com>
Date: Tue, 2 Jul 2002 20:39:20 +0000
Subject: [PATCH] Added list.get-at that returns the value of an item, assumes
 that the item is a node. Added support for n-recursive access to list.at and
 list.get-at to make access to recursive structures easier.

[SVN r14285]
---
 src/util/container.jam | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/util/container.jam b/src/util/container.jam
index d36c1fceb..dad5d271f 100644
--- a/src/util/container.jam
+++ b/src/util/container.jam
@@ -50,9 +50,24 @@ rule list (
         return $(self.value[-1]) ;
     }
     
-    rule at ( index )
+    rule at ( index : * )
     {
-        return $(self.value[$(index)]) ;
+        local r = $(self.value[$(index)]) ;
+        if $(2)
+        {
+            r = [ $(r).at $(2) : $(3) : $(4) : $(5) : $(6) : $(7) : $(8) : $(9) ] ;
+        }
+        return $(r) ;
+    }
+    
+    rule get-at ( index : * )
+    {
+        local r = $(self.value[$(index)]) ;
+        if $(2)
+        {
+            r = [ $(r).at $(2) : $(3) : $(4) : $(5) : $(6) : $(7) : $(8) : $(9) ] ;
+        }
+        return [ $(r).get ] ;
     }
     
     rule push-front ( value )
@@ -147,4 +162,13 @@ local rule __test__ ( )
     assert.false $(l2-alias).empty ;
     $(l2).pop-back ;
     assert.result t : $(l2-alias).back ;
+    
+    local l3 = [ new list ] ;
+    $(l3).push-back [ new list 1 2 3 4 5 ] ;
+    $(l3).push-back [ new list a b c ] ;
+    $(l3).push-back [ new list [ new list x y z ] [ new list 7 8 9 ] ] ;
+    assert.result 1 : $(l3).at 1 : 1 ;
+    assert.result b : $(l3).at 2 : 2 ;
+    assert.result a b c : $(l3).get-at 2 ;
+    assert.result 7 8 9 : $(l3).get-at 3 : 2 ;
 }