47 lines
1.8 KiB
PHP
47 lines
1.8 KiB
PHP
<?php
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/*
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* This file is part of Twig.
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*
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* (c) Fabien Potencier
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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class Twig_Node_Expression_NullCoalesce extends Twig_Node_Expression_Conditional
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{
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public function __construct(Twig_Node $left, Twig_Node $right, $lineno)
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{
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$test = new Twig_Node_Expression_Binary_And(
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new Twig_Node_Expression_Test_Defined(clone $left, 'defined', new Twig_Node(), $left->getTemplateLine()),
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new Twig_Node_Expression_Unary_Not(new Twig_Node_Expression_Test_Null($left, 'null', new Twig_Node(), $left->getTemplateLine()), $left->getTemplateLine()),
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$left->getTemplateLine()
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);
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parent::__construct($test, $left, $right, $lineno);
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}
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public function compile(Twig_Compiler $compiler)
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{
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/*
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* This optimizes only one case. PHP 7 also supports more complex expressions
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* that can return null. So, for instance, if log is defined, log("foo") ?? "..." works,
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* but log($a["foo"]) ?? "..." does not if $a["foo"] is not defined. More advanced
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* cases might be implemented as an optimizer node visitor, but has not been done
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* as benefits are probably not worth the added complexity.
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*/
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if (PHP_VERSION_ID >= 70000 && $this->getNode('expr2') instanceof Twig_Node_Expression_Name) {
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$this->getNode('expr2')->setAttribute('always_defined', true);
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$compiler
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->raw('((')
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->subcompile($this->getNode('expr2'))
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->raw(') ?? (')
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->subcompile($this->getNode('expr3'))
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->raw('))')
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;
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} else {
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parent::compile($compiler);
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}
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}
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}
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