generate_operators_precedence.php

<?php

/*
 * This file is part of Twig.
 *
 * (c) Fabien Potencier
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

use Twig\Environment;
use Twig\ExpressionParser\ExpressionParserDescriptionInterface;
use Twig\ExpressionParser\ExpressionParserType;
use Twig\ExpressionParser\InfixAssociativity;
use Twig\ExpressionParser\InfixExpressionParserInterface;
use Twig\Loader\ArrayLoader;

require_once dirname(__DIR__).'/vendor/autoload.php';

$output = fopen(dirname(__DIR__).'/doc/operators_precedence.rst', 'w');

$twig = new Environment(new ArrayLoader([]));
$descriptionLength = 11;
$expressionParsers = [];
$seen = new SplObjectStorage();
foreach ($twig->getExpressionParsers() as $expressionParser) {
    if (!$seen->offsetExists($expressionParser)) {
        $expressionParsers[] = $expressionParser;
        $seen->offsetSet($expressionParser, true);
        $descriptionLength = max($descriptionLength, $expressionParser instanceof ExpressionParserDescriptionInterface ? strlen($expressionParser->getDescription()) : '');
    }
}

fwrite($output, "\n+------------+------------------+---------+---------------+".str_repeat('-', $descriptionLength + 2)."+\n");
fwrite($output, '| Precedence | Operator         | Type    | Associativity | Description'.str_repeat(' ', $descriptionLength - 11)." |\n");
fwrite($output, '+============+==================+=========+===============+'.str_repeat('=', $descriptionLength + 2).'+');

usort($expressionParsers, static fn ($a, $b) => $b->getPrecedence() <=> $a->getPrecedence());

$previous = null;
foreach ($expressionParsers as $expressionParser) {
    if (null !== $previous) {
        fwrite($output, "\n+------------+------------------+---------+---------------+".str_repeat('-', $descriptionLength + 2).'+');
    }
    $precedence = $expressionParser->getPrecedence();
    $previousPrecedence = $previous ? $previous->getPrecedence() : \PHP_INT_MAX;
    $associativity = $expressionParser instanceof InfixExpressionParserInterface ? (InfixAssociativity::Left === $expressionParser->getAssociativity() ? 'Left' : 'Right') : 'n/a';
    $previousAssociativity = $previous ? ($previous instanceof InfixExpressionParserInterface ? (InfixAssociativity::Left === $previous->getAssociativity() ? 'Left' : 'Right') : 'n/a') : 'n/a';
    if ($previousPrecedence !== $precedence) {
        $previous = null;
    }
    $operatorName = '``'.$expressionParser->getName().'``';
    if ($expressionParser->getAliases()) {
        $operatorName .= ', ``'.implode('``, ``', $expressionParser->getAliases()).'``';
    }
    fwrite($output, rtrim(sprintf("\n| %-10s | %-16s | %-7s | %-13s | %-{$descriptionLength}s |\n",
        (!$previous || $previousPrecedence !== $precedence ? $precedence : '').($expressionParser->getPrecedenceChange() ? ' => '.$expressionParser->getPrecedenceChange()->getNewPrecedence() : ''),
        $operatorName,
        !$previous || ExpressionParserType::getType($previous) !== ExpressionParserType::getType($expressionParser) ? ExpressionParserType::getType($expressionParser)->value : '',
        !$previous || $previousAssociativity !== $associativity ? $associativity : '',
        $expressionParser instanceof ExpressionParserDescriptionInterface ? $expressionParser->getDescription() : '',
    )));
    $previous = $expressionParser;
}
fwrite($output, "\n+------------+------------------+---------+---------------+".str_repeat('-', $descriptionLength + 2)."+\n");
fwrite($output, "\nWhen a precedence will change in the next major version, the new precedence is indicated by the arrow ``=>``.\n");

fclose($output);