4 * This file is part of Twig.
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
11 class Twig_Node_Expression_NullCoalesce extends Twig_Node_Expression_Conditional
13 public function __construct(Twig_NodeInterface $left, Twig_NodeInterface $right, $lineno)
15 $test = new Twig_Node_Expression_Binary_And(
16 new Twig_Node_Expression_Test_Defined(clone $left, 'defined', new Twig_Node(), $left->getTemplateLine()),
17 new Twig_Node_Expression_Unary_Not(new Twig_Node_Expression_Test_Null($left, 'null', new Twig_Node(), $left->getTemplateLine()), $left->getTemplateLine()),
18 $left->getTemplateLine()
21 parent::__construct($test, $left, $right, $lineno);
24 public function compile(Twig_Compiler $compiler)
27 * This optimizes only one case. PHP 7 also supports more complex expressions
28 * that can return null. So, for instance, if log is defined, log("foo") ?? "..." works,
29 * but log($a["foo"]) ?? "..." does not if $a["foo"] is not defined. More advanced
30 * cases might be implemented as an optimizer node visitor, but has not been done
31 * as benefits are probably not worth the added complexity.
33 if (PHP_VERSION_ID >= 70000 && $this->getNode('expr2') instanceof Twig_Node_Expression_Name) {
34 $this->getNode('expr2')->setAttribute('always_defined', true);
37 ->subcompile($this->getNode('expr2'))
39 ->subcompile($this->getNode('expr3'))
43 parent::compile($compiler);