added the merge filter

CHANGELOG

@@ -16,6 +16,7 @@ Backward incompatibilities:
 
 Changes:
 
+ * added the merge filter
  * removed 'is_escaper' option for filters (a left over from the previous version) -- you must use 'is_safe' now instead
  * fixed usage of operators as method names (like is, in, and not)
  * changed the order of execution for node visitors

lib/Twig/Extension/Core.php

@@ -65,6 +65,7 @@ class Twig_Extension_Core extends Twig_Extension
             'sort'    => new Twig_Filter_Function('twig_sort_filter'),
             'range'   => new Twig_Filter_Function('twig_range_filter'),
             'cycle'   => new Twig_Filter_Function('twig_cycle_filter'),
+            'merge'   => new Twig_Filter_Function('twig_array_merge'),
 
             // iteration and runtime
             'default' => new Twig_Filter_Function('twig_default_filter'),
@@ -187,6 +188,15 @@ function twig_urlencode_filter($url, $raw = false)
     return urlencode($url);
 }
 
+function twig_array_merge($arr1, $arr2)
+{
+    if (!is_array($arr1) || !is_array($arr2)) {
+        throw new Twig_Error_Runtime('The merge filter only work with arrays or hashes.');
+    }
+
+    return array_merge($arr1, $arr2);
+}
+
 function twig_join_filter($value, $glue = '')
 {
     return implode($glue, (array) $value);

test/Twig/Tests/Fixtures/filters/merge.test

@@ -0,0 +1,14 @@
+--TEST--
+"merge" filter
+--TEMPLATE--
+{{ items|merge({'bar': 'foo'})|join }}
+{{ items|merge({'bar': 'foo'})|keys|join }}
+{{ {'bar': 'foo'}|merge(items)|join }}
+{{ {'bar': 'foo'}|merge(items)|keys|join }}
+--DATA--
+return array('items' => array('foo' => 'bar'))
+--EXPECT--
+barfoo
+foobar
+foobar
+barfoo