Lazily evaluate blocks pragmas.

The specific example in the docs page about what does not work, is exactly what we need
to make this useful.

Fixes #264

src/Mustache/Compiler.php

@@ -233,9 +233,10 @@ class Mustache_Compiler
     }
 
     const BLOCK_VAR = '
-        $value = $this->resolveValue($context->findInBlock(%s), $context, $indent);
+        $blockFunction = $context->findInBlock(%s);
-        if ($value && !is_array($value) && !is_object($value)) {
+        if (is_callable($blockFunction)) {
-            $buffer .= $value;
+            $boundFunction = $blockFunction->bindTo($this, $this);
+            $boundFunction($context, $buffer);
         } else {
             %s
         }
@@ -258,13 +259,15 @@ class Mustache_Compiler
     {
         $id = var_export($id, true);
 
-        return sprintf($this->prepare(self::BLOCK_VAR, $level), $id, $this->walk($nodes, 2));
+        return sprintf($this->prepare(self::BLOCK_VAR, $level), $id, $this->walk($nodes));
     }
 
     const BLOCK_ARG = '
         // %s block_arg
-        $value = $this->section%s($context, \'\', true);
+        $blockFunction = function(& $context, & $buffer, $indent=\'\') {
-        $newContext[%s] = %s$value;
+            %s
+        };
+        $newContext[%s] = $blockFunction;
     ';
 
     /**
@@ -282,10 +285,10 @@ class Mustache_Compiler
      */
     private function blockArg($nodes, $id, $start, $end, $otag, $ctag, $level)
     {
-        $key = $this->section($nodes, $id, array(), $start, $end, $otag, $ctag, $level, true);
         $id = var_export($id, true);
+        $code = $this->walk($nodes, 1);
 
-        return sprintf($this->prepare(self::BLOCK_ARG, $level), $id, $key, $id, $this->flushIndent());
+        return sprintf($this->prepare(self::BLOCK_ARG, 1), $id, $code, $id);
     }
 
     const SECTION_CALL = '

test/Mustache/Test/Functional/InheritanceTest.php

@@ -433,6 +433,40 @@ class Mustache_Test_Functional_InheritanceTest extends PHPUnit_Framework_TestCas
         $this->assertEquals('default content', $tpl->render($data));
     }
 
+    public function testInheritanceWithLazyEvaluation()
+    {
+        $partials = array(
+            'parent' => '{{#items}}{{$value}}ignored{{/value}}{{/items}}',
+        );
+
+        $this->mustache->setPartials($partials);
+
+        $tpl = $this->mustache->loadTemplate(
+            '{{<parent}}{{$value}}<{{ . }}>{{/value}}{{/parent}}'
+        );
+
+        $data = array('items' => array(1, 2, 3));
+
+        $this->assertEquals('<1><2><3>', $tpl->render($data));
+    }
+
+    public function testInheritanceWithLazyEvaluationWhitespaceIgnored()
+    {
+        $partials = array(
+            'parent' => '{{#items}}{{$value}}\n\nignored\n\n{{/value}}{{/items}}',
+        );
+
+        $this->mustache->setPartials($partials);
+
+        $tpl = $this->mustache->loadTemplate(
+            '{{<parent}}\n\n\n{{$value}}<{{ . }}>{{/value}}\n\n{{/parent}}'
+        );
+
+        $data = array('items' => array(1, 2, 3));
+
+        $this->assertEquals('<1><2><3>', $tpl->render($data));
+    }
+
     /**
      * @dataProvider getIllegalInheritanceExamples
      * @expectedException Mustache_Exception_SyntaxException