Matthias Andreas Benkard | 12a5735 | 2021-12-28 18:02:04 +0100 | [diff] [blame^] | 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 | |
| 12 | namespace Twig\Node\Expression; |
| 13 | |
| 14 | use Twig\Compiler; |
| 15 | use Twig\Node\Expression\Binary\AndBinary; |
| 16 | use Twig\Node\Expression\Test\DefinedTest; |
| 17 | use Twig\Node\Expression\Test\NullTest; |
| 18 | use Twig\Node\Expression\Unary\NotUnary; |
| 19 | use Twig\Node\Node; |
| 20 | |
| 21 | class NullCoalesceExpression extends ConditionalExpression |
| 22 | { |
| 23 | public function __construct(Node $left, Node $right, int $lineno) |
| 24 | { |
| 25 | $test = new DefinedTest(clone $left, 'defined', new Node(), $left->getTemplateLine()); |
| 26 | // for "block()", we don't need the null test as the return value is always a string |
| 27 | if (!$left instanceof BlockReferenceExpression) { |
| 28 | $test = new AndBinary( |
| 29 | $test, |
| 30 | new NotUnary(new NullTest($left, 'null', new Node(), $left->getTemplateLine()), $left->getTemplateLine()), |
| 31 | $left->getTemplateLine() |
| 32 | ); |
| 33 | } |
| 34 | |
| 35 | parent::__construct($test, $left, $right, $lineno); |
| 36 | } |
| 37 | |
| 38 | public function compile(Compiler $compiler): void |
| 39 | { |
| 40 | /* |
| 41 | * This optimizes only one case. PHP 7 also supports more complex expressions |
| 42 | * that can return null. So, for instance, if log is defined, log("foo") ?? "..." works, |
| 43 | * but log($a["foo"]) ?? "..." does not if $a["foo"] is not defined. More advanced |
| 44 | * cases might be implemented as an optimizer node visitor, but has not been done |
| 45 | * as benefits are probably not worth the added complexity. |
| 46 | */ |
| 47 | if ($this->getNode('expr2') instanceof NameExpression) { |
| 48 | $this->getNode('expr2')->setAttribute('always_defined', true); |
| 49 | $compiler |
| 50 | ->raw('((') |
| 51 | ->subcompile($this->getNode('expr2')) |
| 52 | ->raw(') ?? (') |
| 53 | ->subcompile($this->getNode('expr3')) |
| 54 | ->raw('))') |
| 55 | ; |
| 56 | } else { |
| 57 | parent::compile($compiler); |
| 58 | } |
| 59 | } |
| 60 | } |