added if modifier support to for loop like {% for k in v if k is odd %}

lib/Twig/Node/For.php

@@ -18,9 +18,9 @@
  */
 class Twig_Node_For extends Twig_Node
 {
-    public function __construct(Twig_Node_Expression_AssignName $keyTarget, Twig_Node_Expression_AssignName $valueTarget, Twig_Node_Expression $seq, Twig_NodeInterface $body, Twig_NodeInterface $else = null, $lineno, $tag = null)
+    public function __construct(Twig_Node_Expression_AssignName $keyTarget, Twig_Node_Expression_AssignName $valueTarget, Twig_Node_Expression $seq, Twig_Node_Expression $ifexpr = null, Twig_NodeInterface $body, Twig_NodeInterface $else = null, $lineno, $tag = null)
     {
-        parent::__construct(array('key_target' => $keyTarget, 'value_target' => $valueTarget, 'seq' => $seq, 'body' => $body, 'else' => $else), array('with_loop' => true), $lineno, $tag);
+        parent::__construct(array('key_target' => $keyTarget, 'value_target' => $valueTarget, 'seq' => $seq, 'ifexpr' => $ifexpr, 'body' => $body, 'else' => $else), array('with_loop' => true), $lineno, $tag);
     }
 
     /**
@@ -72,6 +72,15 @@ class Twig_Node_For extends Twig_Node
             ->indent()
         ;
 
+        if (null !== $this->getNode('ifexpr')) {
+            $compiler
+                ->write("if (")
+                ->subcompile($this->getNode('ifexpr'))
+                ->raw(") {\n")
+                ->indent()
+            ;
+        }
+
         $compiler->subcompile($this->getNode('body'));
 
         if (null !== $this->getNode('else')) {
@@ -93,6 +102,13 @@ class Twig_Node_For extends Twig_Node
             ;
         }
 
+        if (null !== $this->getNode('ifexpr')) {
+            $compiler
+                ->outdent()
+                ->write("}\n")
+            ;
+        }
+
         $compiler
             ->outdent()
             ->write("}\n")

lib/Twig/TokenParser/For.php

@@ -25,6 +25,12 @@ class Twig_TokenParser_For extends Twig_TokenParser
         $this->parser->getStream()->expect(Twig_Token::OPERATOR_TYPE, 'in');
         $seq = $this->parser->getExpressionParser()->parseExpression();
 
+        $ifexpr = null;
+        if ($this->parser->getStream()->test(Twig_Token::NAME_TYPE, 'if')) {
+            $this->parser->getStream()->next();
+            $ifexpr = $this->parser->getExpressionParser()->parseExpression();
+        }
+
         $this->parser->getStream()->expect(Twig_Token::BLOCK_END_TYPE);
         $body = $this->parser->subparse(array($this, 'decideForFork'));
         if ($this->parser->getStream()->next()->getValue() == 'else') {
@@ -43,7 +49,7 @@ class Twig_TokenParser_For extends Twig_TokenParser
             $valueTarget = $targets->getNode(0);
         }
 
-        return new Twig_Node_For($keyTarget, $valueTarget, $seq, $body, $else, $lineno, $this->getTag());
+        return new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, $lineno, $this->getTag());
     }
 
     public function decideForFork(Twig_Token $token)

test/Twig/Tests/Node/ForTest.php

@@ -21,19 +21,21 @@ class Twig_Tests_Node_ForTest extends Twig_Tests_Node_TestCase
         $keyTarget = new Twig_Node_Expression_AssignName('key', 0);
         $valueTarget = new Twig_Node_Expression_AssignName('item', 0);
         $seq = new Twig_Node_Expression_Name('items', 0);
+        $ifexpr = new Twig_Node_Expression_Constant(true, 0);
         $body = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
         $else = null;
-        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $body, $else, 0);
+        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, 0);
         $node->setAttribute('with_loop', false);
 
         $this->assertEquals($keyTarget, $node->getNode('key_target'));
         $this->assertEquals($valueTarget, $node->getNode('value_target'));
         $this->assertEquals($seq, $node->getNode('seq'));
+        $this->assertEquals($ifexpr, $node->getNode('ifexpr'));
         $this->assertEquals($body, $node->getNode('body'));
         $this->assertEquals(null, $node->getNode('else'));
 
         $else = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
-        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $body, $else, 0);
+        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, 0);
         $node->setAttribute('with_loop', false);
         $this->assertEquals($else, $node->getNode('else'));
     }
@@ -54,9 +56,10 @@ class Twig_Tests_Node_ForTest extends Twig_Tests_Node_TestCase
         $keyTarget = new Twig_Node_Expression_AssignName('key', 0);
         $valueTarget = new Twig_Node_Expression_AssignName('item', 0);
         $seq = new Twig_Node_Expression_Name('items', 0);
+        $ifexpr = null;
         $body = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
         $else = null;
-        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $body, $else, 0);
+        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, 0);
         $node->setAttribute('with_loop', false);
 
         $tests[] = array($node, <<<EOF
@@ -74,9 +77,10 @@ EOF
         $keyTarget = new Twig_Node_Expression_AssignName('k', 0);
         $valueTarget = new Twig_Node_Expression_AssignName('v', 0);
         $seq = new Twig_Node_Expression_Name('values', 0);
+        $ifexpr = null;
         $body = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
         $else = null;
-        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $body, $else, 0);
+        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, 0);
         $node->setAttribute('with_loop', true);
 
         $tests[] = array($node, <<<EOF
@@ -115,9 +119,54 @@ EOF
         $keyTarget = new Twig_Node_Expression_AssignName('k', 0);
         $valueTarget = new Twig_Node_Expression_AssignName('v', 0);
         $seq = new Twig_Node_Expression_Name('values', 0);
+        $ifexpr = new Twig_Node_Expression_Constant(true, 0);
+        $body = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
+        $else = null;
+        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, 0);
+        $node->setAttribute('with_loop', true);
+
+        $tests[] = array($node, <<<EOF
+\$context['_parent'] = (array) \$context;
+\$context['_seq'] = twig_ensure_traversable((isset(\$context['values']) ? \$context['values'] : null));
+\$context['loop'] = array(
+  'parent' => \$context['_parent'],
+  'index0' => 0,
+  'index'  => 1,
+  'first'  => true,
+);
+if (is_array(\$context['_seq']) || (is_object(\$context['_seq']) && \$context['_seq'] instanceof Countable)) {
+    \$length = count(\$context['_seq']);
+    \$context['loop']['revindex0'] = \$length - 1;
+    \$context['loop']['revindex'] = \$length;
+    \$context['loop']['length'] = \$length;
+    \$context['loop']['last'] = 1 === \$length;
+}
+foreach (\$context['_seq'] as \$context['k'] => \$context['v']) {
+    if (true) {
+        echo (isset(\$context['foo']) ? \$context['foo'] : null);
+        ++\$context['loop']['index0'];
+        ++\$context['loop']['index'];
+        \$context['loop']['first'] = false;
+        if (isset(\$context['loop']['length'])) {
+            --\$context['loop']['revindex0'];
+            --\$context['loop']['revindex'];
+            \$context['loop']['last'] = 0 === \$context['loop']['revindex0'];
+        }
+    }
+}
+\$_parent = \$context['_parent'];
+unset(\$context['_seq'], \$context['_iterated'], \$context['k'], \$context['v'], \$context['_parent'], \$context['loop']);
+\$context = array_merge(\$_parent, array_intersect_key(\$context, \$_parent));
+EOF
+        );
+
+        $keyTarget = new Twig_Node_Expression_AssignName('k', 0);
+        $valueTarget = new Twig_Node_Expression_AssignName('v', 0);
+        $seq = new Twig_Node_Expression_Name('values', 0);
+        $ifexpr = null;
         $body = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
         $else = new Twig_Node_Print(new Twig_Node_Expression_Name('foo', 0), 0);
-        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $body, $else, 0);
+        $node = new Twig_Node_For($keyTarget, $valueTarget, $seq, $ifexpr, $body, $else, 0);
         $node->setAttribute('with_loop', true);
 
         $tests[] = array($node, <<<EOF