vendor/twig/twig/lib/Twig/Node/Expression/NullCoalesce.php

   1 <?php
   2
   3 /*
   4  * This file is part of Twig.
   5  *
   6  * (c) Fabien Potencier
   7  *
   8  * For the full copyright and license information, please view the LICENSE
   9  * file that was distributed with this source code.
  10  */
  11 class Twig_Node_Expression_NullCoalesce extends Twig_Node_Expression_Conditional
  12 {
  13     public function __construct(Twig_NodeInterface $left, Twig_NodeInterface $right, $lineno)
  14     {
  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             $left->getTemplateLine()
  19         );
  20
  21         parent::__construct($test, $left, $right, $lineno);
  22     }
  23
  24     public function compile(Twig_Compiler $compiler)
  25     {
  26         /*
  27          * This optimizes only one case. PHP 7 also supports more complex expressions
  28          * that can return null. So, for instance, if log is defined, log("foo") ?? "..." works,
  29          * but log($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.
  32          */
  33         if (PHP_VERSION_ID >= 70000 && $this->getNode('expr2') instanceof Twig_Node_Expression_Name) {
  34             $this->getNode('expr2')->setAttribute('always_defined', true);
  35             $compiler
  36                 ->raw('((')
  37                 ->subcompile($this->getNode('expr2'))
  38                 ->raw(') ?? (')
  39                 ->subcompile($this->getNode('expr3'))
  40                 ->raw('))')
  41             ;
  42         } else {
  43             parent::compile($compiler);
  44         }
  45     }
  46 }
  47
  48 class_alias('Twig_Node_Expression_NullCoalesce', 'Twig\Node\Expression\NullCoalesceExpression', false);