ExpressionParser.php

<?php


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

use Twig\Attribute\FirstClassTwigCallableReady;
use Twig\Error\SyntaxError;
use Twig\Node\EmptyNode;
use Twig\Node\Expression\AbstractExpression;
use Twig\Node\Expression\ArrayExpression;
use Twig\Node\Expression\ArrowFunctionExpression;
use Twig\Node\Expression\Binary\AbstractBinary;
use Twig\Node\Expression\Binary\ConcatBinary;
use Twig\Node\Expression\ConditionalExpression;
use Twig\Node\Expression\ConstantExpression;
use Twig\Node\Expression\GetAttrExpression;
use Twig\Node\Expression\MacroReferenceExpression;
use Twig\Node\Expression\NameExpression;
use Twig\Node\Expression\TestExpression;
use Twig\Node\Expression\Unary\AbstractUnary;
use Twig\Node\Expression\Unary\NegUnary;
use Twig\Node\Expression\Unary\NotUnary;
use Twig\Node\Expression\Unary\PosUnary;
use Twig\Node\Expression\Unary\SpreadUnary;
use Twig\Node\Expression\Variable\AssignContextVariable;
use Twig\Node\Expression\Variable\ContextVariable;
use Twig\Node\Expression\Variable\LocalVariable;
use Twig\Node\Expression\Variable\TemplateVariable;
use Twig\Node\Node;
use Twig\Node\Nodes;

/**
 * Parses expressions.
 *
 * This parser implements a "Precedence climbing" algorithm.
 *
 * @see https://www.engr.mun.ca/~theo/Misc/exp_parsing.htm
 * @see https://en.wikipedia.org/wiki/Operator-precedence_parser
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class ExpressionParser {
    public const OPERATOR_LEFT = 1;
    public const OPERATOR_RIGHT = 2;
    
    /** @var array<string, array{precedence: int, precedence_change?: OperatorPrecedenceChange, class: class-string<AbstractUnary>}> */
    private $unaryOperators;
    
    /** @var array<string, array{precedence: int, precedence_change?: OperatorPrecedenceChange, class: class-string<AbstractBinary>, associativity: self::OPERATOR_*}> */
    private $binaryOperators;
    private $readyNodes = [];
    private array $precedenceChanges = [];
    private bool $deprecationCheck = true;
    public function __construct(Parser $parser, Environment $env) {
        $this->unaryOperators = $env->getUnaryOperators();
        $this->binaryOperators = $env->getBinaryOperators();
        $ops = [];
        foreach ($this->unaryOperators as $n => $c) {
            $ops[] = $c + [
                'name' => $n,
                'type' => 'unary',
            ];
        }
        foreach ($this->binaryOperators as $n => $c) {
            $ops[] = $c + [
                'name' => $n,
                'type' => 'binary',
            ];
        }
        foreach ($ops as $config) {
            if (!isset($config['precedence_change'])) {
                continue;
            }
            $name = $config['type'] . '_' . $config['name'];
            $min = min($config['precedence_change']->getNewPrecedence(), $config['precedence']);
            $max = max($config['precedence_change']->getNewPrecedence(), $config['precedence']);
            foreach ($ops as $c) {
                if ($c['precedence'] > $min && $c['precedence'] < $max) {
                    $this->precedenceChanges[$c['type'] . '_' . $c['name']][] = $name;
                }
            }
        }
    }
    public function parseExpression($precedence = 0) {
        if (func_num_args() > 1) {
            trigger_deprecation('twig/twig', '3.15', 'Passing a second argument ($allowArrow) to "%s()" is deprecated.', __METHOD__);
        }
        if ($arrow = $this->parseArrow()) {
            return $arrow;
        }
        $expr = $this->getPrimary();
        $token = $this->parser
            ->getCurrentToken();
        while ($this->isBinary($token) && $this->binaryOperators[$token->getValue()]['precedence'] >= $precedence) {
            $op = $this->binaryOperators[$token->getValue()];
            $this->parser
                ->getStream()
                ->next();
            if ('is not' === $token->getValue()) {
                $expr = $this->parseNotTestExpression($expr);
            }
            elseif ('is' === $token->getValue()) {
                $expr = $this->parseTestExpression($expr);
            }
            elseif (isset($op['callable'])) {
                $expr = $op['callable']($this->parser, $expr);
            }
            else {
                $previous = $this->setDeprecationCheck(true);
                try {
                    $expr1 = $this->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
                } finally {
                    $this->setDeprecationCheck($previous);
                }
                $class = $op['class'];
                $expr = new $class($expr, $expr1, $token->getLine());
            }
            $expr->setAttribute('operator', 'binary_' . $token->getValue());
            $this->triggerPrecedenceDeprecations($expr);
            $token = $this->parser
                ->getCurrentToken();
        }
        if (0 === $precedence) {
            return $this->parseConditionalExpression($expr);
        }
        return $expr;
    }
    private function triggerPrecedenceDeprecations(AbstractExpression $expr) : void {
        // Check that the all nodes that are between the 2 precedences have explicit parentheses
        if (!$expr->hasAttribute('operator') || !isset($this->precedenceChanges[$expr->getAttribute('operator')])) {
            return;
        }
        if (str_starts_with($unaryOp = $expr->getAttribute('operator'), 'unary')) {
            if ($expr->hasExplicitParentheses()) {
                return;
            }
            $target = explode('_', $unaryOp)[1];
            $change = $this->unaryOperators[$target]['precedence_change'];
            
            /** @var AbstractExpression $node */
            $node = $expr->getNode('node');
            foreach ($this->precedenceChanges as $operatorName => $changes) {
                if (!in_array($unaryOp, $changes)) {
                    continue;
                }
                if ($node->hasAttribute('operator') && $operatorName === $node->getAttribute('operator')) {
                    trigger_deprecation($change->getPackage(), $change->getVersion(), \sprintf('Add explicit parentheses around the "%s" unary operator to avoid behavior change in the next major version as its precedence will change in "%s" at line %d.', $target, $this->parser
                        ->getStream()
                        ->getSourceContext()
                        ->getName(), $node->getTemplateLine()));
                }
            }
        }
        else {
            foreach ($this->precedenceChanges[$expr->getAttribute('operator')] as $operatorName) {
                foreach ($expr as $node) {
                    
                    /** @var AbstractExpression $node */
                    if ($node->hasAttribute('operator') && $operatorName === $node->getAttribute('operator') && !$node->hasExplicitParentheses()) {
                        $op = explode('_', $operatorName)[1];
                        $change = $this->binaryOperators[$op]['precedence_change'];
                        trigger_deprecation($change->getPackage(), $change->getVersion(), \sprintf('Add explicit parentheses around the "%s" binary operator to avoid behavior change in the next major version as its precedence will change in "%s" at line %d.', $op, $this->parser
                            ->getStream()
                            ->getSourceContext()
                            ->getName(), $node->getTemplateLine()));
                    }
                }
            }
        }
    }
    
    /**
     * @return ArrowFunctionExpression|null
     */
    private function parseArrow() {
        $stream = $this->parser
            ->getStream();
        // short array syntax (one argument, no parentheses)?
        if ($stream->look(1)
            ->test(Token::ARROW_TYPE)) {
            $line = $stream->getCurrent()
                ->getLine();
            $token = $stream->expect(Token::NAME_TYPE);
            $names = [
                new AssignContextVariable($token->getValue(), $token->getLine()),
            ];
            $stream->expect(Token::ARROW_TYPE);
            return new ArrowFunctionExpression($this->parseExpression(), new Nodes($names), $line);
        }
        // first, determine if we are parsing an arrow function by finding => (long form)
        $i = 0;
        if (!$stream->look($i)
            ->test(Token::PUNCTUATION_TYPE, '(')) {
            return null;
        }
        ++$i;
        while (true) {
            // variable name
            ++$i;
            if (!$stream->look($i)
                ->test(Token::PUNCTUATION_TYPE, ',')) {
                break;
            }
            ++$i;
        }
        if (!$stream->look($i)
            ->test(Token::PUNCTUATION_TYPE, ')')) {
            return null;
        }
        ++$i;
        if (!$stream->look($i)
            ->test(Token::ARROW_TYPE)) {
            return null;
        }
        // yes, let's parse it properly
        $token = $stream->expect(Token::PUNCTUATION_TYPE, '(');
        $line = $token->getLine();
        $names = [];
        while (true) {
            $token = $stream->expect(Token::NAME_TYPE);
            $names[] = new AssignContextVariable($token->getValue(), $token->getLine());
            if (!$stream->nextIf(Token::PUNCTUATION_TYPE, ',')) {
                break;
            }
        }
        $stream->expect(Token::PUNCTUATION_TYPE, ')');
        $stream->expect(Token::ARROW_TYPE);
        return new ArrowFunctionExpression($this->parseExpression(), new Nodes($names), $line);
    }
    private function getPrimary() : AbstractExpression {
        $token = $this->parser
            ->getCurrentToken();
        if ($this->isUnary($token)) {
            $operator = $this->unaryOperators[$token->getValue()];
            $this->parser
                ->getStream()
                ->next();
            $expr = $this->parseExpression($operator['precedence']);
            $class = $operator['class'];
            $expr = new $class($expr, $token->getLine());
            $expr->setAttribute('operator', 'unary_' . $token->getValue());
            if ($this->deprecationCheck) {
                $this->triggerPrecedenceDeprecations($expr);
            }
            return $this->parsePostfixExpression($expr);
        }
        elseif ($token->test(Token::PUNCTUATION_TYPE, '(')) {
            $this->parser
                ->getStream()
                ->next();
            $previous = $this->setDeprecationCheck(false);
            try {
                $expr = $this->parseExpression()
                    ->setExplicitParentheses();
            } finally {
                $this->setDeprecationCheck($previous);
            }
            $this->parser
                ->getStream()
                ->expect(Token::PUNCTUATION_TYPE, ')', 'An opened parenthesis is not properly closed');
            return $this->parsePostfixExpression($expr);
        }
        return $this->parsePrimaryExpression();
    }
    private function parseConditionalExpression($expr) : AbstractExpression {
        while ($this->parser
            ->getStream()
            ->nextIf(Token::PUNCTUATION_TYPE, '?')) {
            if (!$this->parser
                ->getStream()
                ->nextIf(Token::PUNCTUATION_TYPE, ':')) {
                $expr2 = $this->parseExpression();
                if ($this->parser
                    ->getStream()
                    ->nextIf(Token::PUNCTUATION_TYPE, ':')) {
                    // Ternary operator (expr ? expr2 : expr3)
                    $expr3 = $this->parseExpression();
                }
                else {
                    // Ternary without else (expr ? expr2)
                    $expr3 = new ConstantExpression('', $this->parser
                        ->getCurrentToken()
                        ->getLine());
                }
            }
            else {
                // Ternary without then (expr ?: expr3)
                $expr2 = $expr;
                $expr3 = $this->parseExpression();
            }
            $expr = new ConditionalExpression($expr, $expr2, $expr3, $this->parser
                ->getCurrentToken()
                ->getLine());
        }
        return $expr;
    }
    private function isUnary(Token $token) : bool {
        return $token->test(Token::OPERATOR_TYPE) && isset($this->unaryOperators[$token->getValue()]);
    }
    private function isBinary(Token $token) : bool {
        return $token->test(Token::OPERATOR_TYPE) && isset($this->binaryOperators[$token->getValue()]);
    }
    public function parsePrimaryExpression() {
        $token = $this->parser
            ->getCurrentToken();
        switch ($token->getType()) {
            case Token::NAME_TYPE:
                $this->parser
                    ->getStream()
                    ->next();
                switch ($token->getValue()) {
                    case 'true':
                    case 'TRUE':
                        $node = new ConstantExpression(true, $token->getLine());
                        break;
                    case 'false':
                    case 'FALSE':
                        $node = new ConstantExpression(false, $token->getLine());
                        break;
                    case 'none':
                    case 'NONE':
                    case 'null':
                    case 'NULL':
                        $node = new ConstantExpression(null, $token->getLine());
                        break;
                    default:
                        if ('(' === $this->parser
                            ->getCurrentToken()
                            ->getValue()) {
                            $node = $this->getFunctionNode($token->getValue(), $token->getLine());
                        }
                        else {
                            $node = new ContextVariable($token->getValue(), $token->getLine());
                        }
                }
                break;
            case Token::NUMBER_TYPE:
                $this->parser
                    ->getStream()
                    ->next();
                $node = new ConstantExpression($token->getValue(), $token->getLine());
                break;
            case Token::STRING_TYPE:
            case Token::INTERPOLATION_START_TYPE:
                $node = $this->parseStringExpression();
                break;
            case Token::PUNCTUATION_TYPE:
                $node = match ($token->getValue()) {    '[' => $this->parseSequenceExpression(),
                    '{' => $this->parseMappingExpression(),
                    default => throw new SyntaxError(\sprintf('Unexpected token "%s" of value "%s".', Token::typeToEnglish($token->getType()), $token->getValue()), $token->getLine(), $this->parser
                        ->getStream()
                        ->getSourceContext()),
                
                };
                break;
            case Token::OPERATOR_TYPE:
                if (preg_match(Lexer::REGEX_NAME, $token->getValue(), $matches) && $matches[0] == $token->getValue()) {
                    // in this context, string operators are variable names
                    $this->parser
                        ->getStream()
                        ->next();
                    $node = new ContextVariable($token->getValue(), $token->getLine());
                    break;
                }
                if ('=' === $token->getValue() && ('==' === $this->parser
                    ->getStream()
                    ->look(-1)
                    ->getValue() || '!=' === $this->parser
                    ->getStream()
                    ->look(-1)
                    ->getValue())) {
                    throw new SyntaxError(\sprintf('Unexpected operator of value "%s". Did you try to use "===" or "!==" for strict comparison? Use "is same as(value)" instead.', $token->getValue()), $token->getLine(), $this->parser
                        ->getStream()
                        ->getSourceContext());
                }
            // no break
            default:
                throw new SyntaxError(\sprintf('Unexpected token "%s" of value "%s".', Token::typeToEnglish($token->getType()), $token->getValue()), $token->getLine(), $this->parser
                    ->getStream()
                    ->getSourceContext());
        }
        return $this->parsePostfixExpression($node);
    }
    public function parseStringExpression() {
        $stream = $this->parser
            ->getStream();
        $nodes = [];
        // a string cannot be followed by another string in a single expression
        $nextCanBeString = true;
        while (true) {
            if ($nextCanBeString && ($token = $stream->nextIf(Token::STRING_TYPE))) {
                $nodes[] = new ConstantExpression($token->getValue(), $token->getLine());
                $nextCanBeString = false;
            }
            elseif ($stream->nextIf(Token::INTERPOLATION_START_TYPE)) {
                $nodes[] = $this->parseExpression();
                $stream->expect(Token::INTERPOLATION_END_TYPE);
                $nextCanBeString = true;
            }
            else {
                break;
            }
        }
        $expr = array_shift($nodes);
        foreach ($nodes as $node) {
            $expr = new ConcatBinary($expr, $node, $node->getTemplateLine());
        }
        return $expr;
    }
    
    /**
     * @deprecated since Twig 3.11, use parseSequenceExpression() instead
     */
    public function parseArrayExpression() {
        trigger_deprecation('twig/twig', '3.11', 'Calling "%s()" is deprecated, use "parseSequenceExpression()" instead.', __METHOD__);
        return $this->parseSequenceExpression();
    }
    public function parseSequenceExpression() {
        $stream = $this->parser
            ->getStream();
        $stream->expect(Token::PUNCTUATION_TYPE, '[', 'A sequence element was expected');
        $node = new ArrayExpression([], $stream->getCurrent()
            ->getLine());
        $first = true;
        while (!$stream->test(Token::PUNCTUATION_TYPE, ']')) {
            if (!$first) {
                $stream->expect(Token::PUNCTUATION_TYPE, ',', 'A sequence element must be followed by a comma');
                // trailing ,?
                if ($stream->test(Token::PUNCTUATION_TYPE, ']')) {
                    break;
                }
            }
            $first = false;
            if ($stream->nextIf(Token::SPREAD_TYPE)) {
                $expr = $this->parseExpression();
                $expr->setAttribute('spread', true);
                $node->addElement($expr);
            }
            else {
                $node->addElement($this->parseExpression());
            }
        }
        $stream->expect(Token::PUNCTUATION_TYPE, ']', 'An opened sequence is not properly closed');
        return $node;
    }
    
    /**
     * @deprecated since Twig 3.11, use parseMappingExpression() instead
     */
    public function parseHashExpression() {
        trigger_deprecation('twig/twig', '3.11', 'Calling "%s()" is deprecated, use "parseMappingExpression()" instead.', __METHOD__);
        return $this->parseMappingExpression();
    }
    public function parseMappingExpression() {
        $stream = $this->parser
            ->getStream();
        $stream->expect(Token::PUNCTUATION_TYPE, '{', 'A mapping element was expected');
        $node = new ArrayExpression([], $stream->getCurrent()
            ->getLine());
        $first = true;
        while (!$stream->test(Token::PUNCTUATION_TYPE, '}')) {
            if (!$first) {
                $stream->expect(Token::PUNCTUATION_TYPE, ',', 'A mapping value must be followed by a comma');
                // trailing ,?
                if ($stream->test(Token::PUNCTUATION_TYPE, '}')) {
                    break;
                }
            }
            $first = false;
            if ($stream->nextIf(Token::SPREAD_TYPE)) {
                $value = $this->parseExpression();
                $value->setAttribute('spread', true);
                $node->addElement($value);
                continue;
            }
            // a mapping key can be:
            //
            //  * a number -- 12
            //  * a string -- 'a'
            //  * a name, which is equivalent to a string -- a
            //  * an expression, which must be enclosed in parentheses -- (1 + 2)
            if ($token = $stream->nextIf(Token::NAME_TYPE)) {
                $key = new ConstantExpression($token->getValue(), $token->getLine());
                // {a} is a shortcut for {a:a}
                if ($stream->test(Token::PUNCTUATION_TYPE, [
                    ',',
                    '}',
                ])) {
                    $value = new ContextVariable($key->getAttribute('value'), $key->getTemplateLine());
                    $node->addElement($value, $key);
                    continue;
                }
            }
            elseif (($token = $stream->nextIf(Token::STRING_TYPE)) || ($token = $stream->nextIf(Token::NUMBER_TYPE))) {
                $key = new ConstantExpression($token->getValue(), $token->getLine());
            }
            elseif ($stream->test(Token::PUNCTUATION_TYPE, '(')) {
                $key = $this->parseExpression();
            }
            else {
                $current = $stream->getCurrent();
                throw new SyntaxError(\sprintf('A mapping key must be a quoted string, a number, a name, or an expression enclosed in parentheses (unexpected token "%s" of value "%s".', Token::typeToEnglish($current->getType()), $current->getValue()), $current->getLine(), $stream->getSourceContext());
            }
            $stream->expect(Token::PUNCTUATION_TYPE, ':', 'A mapping key must be followed by a colon (:)');
            $value = $this->parseExpression();
            $node->addElement($value, $key);
        }
        $stream->expect(Token::PUNCTUATION_TYPE, '}', 'An opened mapping is not properly closed');
        return $node;
    }
    public function parsePostfixExpression($node) {
        while (true) {
            $token = $this->parser
                ->getCurrentToken();
            if (Token::PUNCTUATION_TYPE == $token->getType()) {
                if ('.' == $token->getValue() || '[' == $token->getValue()) {
                    $node = $this->parseSubscriptExpression($node);
                }
                elseif ('|' == $token->getValue()) {
                    $node = $this->parseFilterExpression($node);
                }
                else {
                    break;
                }
            }
            else {
                break;
            }
        }
        return $node;
    }
    public function getFunctionNode($name, $line) {
        if (null !== ($alias = $this->parser
            ->getImportedSymbol('function', $name))) {
            return new MacroReferenceExpression($alias['node']->getNode('var'), $alias['name'], $this->createArguments($line), $line);
        }
        $args = $this->parseOnlyArguments();
        $function = $this->getFunction($name, $line);
        if ($function->getParserCallable()) {
            $fakeNode = new EmptyNode($line);
            $fakeNode->setSourceContext($this->parser
                ->getStream()
                ->getSourceContext());
            return $function->getParserCallable()($this->parser, $fakeNode, $args, $line);
        }
        if (!isset($this->readyNodes[$class = $function->getNodeClass()])) {
            $this->readyNodes[$class] = (bool) (new \ReflectionClass($class))->getConstructor()
                ->getAttributes(FirstClassTwigCallableReady::class);
        }
        if (!($ready = $this->readyNodes[$class])) {
            trigger_deprecation('twig/twig', '3.12', 'Twig node "%s" is not marked as ready for passing a "TwigFunction" in the constructor instead of its name; please update your code and then add #[FirstClassTwigCallableReady] attribute to the constructor.', $class);
        }
        return new $class($ready ? $function : $function->getName(), $args, $line);
    }
    public function parseSubscriptExpression($node) {
        if ('.' === $this->parser
            ->getStream()
            ->next()
            ->getValue()) {
            return $this->parseSubscriptExpressionDot($node);
        }
        return $this->parseSubscriptExpressionArray($node);
    }
    public function parseFilterExpression($node) {
        $this->parser
            ->getStream()
            ->next();
        return $this->parseFilterExpressionRaw($node);
    }
    public function parseFilterExpressionRaw($node) {
        if (\func_num_args() > 1) {
            trigger_deprecation('twig/twig', '3.12', 'Passing a second argument to "%s()" is deprecated.', __METHOD__);
        }
        while (true) {
            $token = $this->parser
                ->getStream()
                ->expect(Token::NAME_TYPE);
            if (!$this->parser
                ->getStream()
                ->test(Token::PUNCTUATION_TYPE, '(')) {
                $arguments = new EmptyNode();
            }
            else {
                $arguments = $this->parseOnlyArguments();
            }
            $filter = $this->getFilter($token->getValue(), $token->getLine());
            $ready = true;
            if (!isset($this->readyNodes[$class = $filter->getNodeClass()])) {
                $this->readyNodes[$class] = (bool) (new \ReflectionClass($class))->getConstructor()
                    ->getAttributes(FirstClassTwigCallableReady::class);
            }
            if (!($ready = $this->readyNodes[$class])) {
                trigger_deprecation('twig/twig', '3.12', 'Twig node "%s" is not marked as ready for passing a "TwigFilter" in the constructor instead of its name; please update your code and then add #[FirstClassTwigCallableReady] attribute to the constructor.', $class);
            }
            $node = new $class($node, $ready ? $filter : new ConstantExpression($filter->getName(), $token->getLine()), $arguments, $token->getLine());
            if (!$this->parser
                ->getStream()
                ->test(Token::PUNCTUATION_TYPE, '|')) {
                break;
            }
            $this->parser
                ->getStream()
                ->next();
        }
        return $node;
    }
    
    /**
     * Parses arguments.
     *
     * @return Node
     *
     * @throws SyntaxError
     */
    public function parseArguments() {
        $namedArguments = false;
        $definition = false;
        if (func_num_args() > 1) {
            $definition = func_get_arg(1);
        }
        if (func_num_args() > 0) {
            trigger_deprecation('twig/twig', '3.15', 'Passing arguments to "%s()" is deprecated.', __METHOD__);
            $namedArguments = func_get_arg(0);
        }
        $args = [];
        $stream = $this->parser
            ->getStream();
        $stream->expect(Token::PUNCTUATION_TYPE, '(', 'A list of arguments must begin with an opening parenthesis');
        $hasSpread = false;
        while (!$stream->test(Token::PUNCTUATION_TYPE, ')')) {
            if ($args) {
                $stream->expect(Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
                // if the comma above was a trailing comma, early exit the argument parse loop
                if ($stream->test(Token::PUNCTUATION_TYPE, ')')) {
                    break;
                }
            }
            if ($definition) {
                $token = $stream->expect(Token::NAME_TYPE, null, 'An argument must be a name');
                $value = new ContextVariable($token->getValue(), $this->parser
                    ->getCurrentToken()
                    ->getLine());
            }
            else {
                if ($stream->nextIf(Token::SPREAD_TYPE)) {
                    $hasSpread = true;
                    $value = new SpreadUnary($this->parseExpression(), $stream->getCurrent()
                        ->getLine());
                }
                elseif ($hasSpread) {
                    throw new SyntaxError('Normal arguments must be placed before argument unpacking.', $stream->getCurrent()
                        ->getLine(), $stream->getSourceContext());
                }
                else {
                    $value = $this->parseExpression();
                }
            }
            $name = null;
            if ($namedArguments && (($token = $stream->nextIf(Token::OPERATOR_TYPE, '=')) || !$definition && ($token = $stream->nextIf(Token::PUNCTUATION_TYPE, ':')))) {
                if (!$value instanceof NameExpression) {
                    throw new SyntaxError(\sprintf('A parameter name must be a string, "%s" given.', \get_class($value)), $token->getLine(), $stream->getSourceContext());
                }
                $name = $value->getAttribute('name');
                if ($definition) {
                    $value = $this->getPrimary();
                    if (!$this->checkConstantExpression($value)) {
                        throw new SyntaxError('A default value for an argument must be a constant (a boolean, a string, a number, a sequence, or a mapping).', $token->getLine(), $stream->getSourceContext());
                    }
                }
                else {
                    $value = $this->parseExpression();
                }
            }
            if ($definition) {
                if (null === $name) {
                    $name = $value->getAttribute('name');
                    $value = new ConstantExpression(null, $this->parser
                        ->getCurrentToken()
                        ->getLine());
                    $value->setAttribute('is_implicit', true);
                }
                $args[$name] = $value;
            }
            else {
                if (null === $name) {
                    $args[] = $value;
                }
                else {
                    $args[$name] = $value;
                }
            }
        }
        $stream->expect(Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');
        return new Nodes($args);
    }
    public function parseAssignmentExpression() {
        $stream = $this->parser
            ->getStream();
        $targets = [];
        while (true) {
            $token = $this->parser
                ->getCurrentToken();
            if ($stream->test(Token::OPERATOR_TYPE) && preg_match(Lexer::REGEX_NAME, $token->getValue())) {
                // in this context, string operators are variable names
                $this->parser
                    ->getStream()
                    ->next();
            }
            else {
                $stream->expect(Token::NAME_TYPE, null, 'Only variables can be assigned to');
            }
            $targets[] = new AssignContextVariable($token->getValue(), $token->getLine());
            if (!$stream->nextIf(Token::PUNCTUATION_TYPE, ',')) {
                break;
            }
        }
        return new Nodes($targets);
    }
    public function parseMultitargetExpression() {
        $targets = [];
        while (true) {
            $targets[] = $this->parseExpression();
            if (!$this->parser
                ->getStream()
                ->nextIf(Token::PUNCTUATION_TYPE, ',')) {
                break;
            }
        }
        return new Nodes($targets);
    }
    private function parseNotTestExpression(Node $node) : NotUnary {
        return new NotUnary($this->parseTestExpression($node), $this->parser
            ->getCurrentToken()
            ->getLine());
    }
    private function parseTestExpression(Node $node) : TestExpression {
        $stream = $this->parser
            ->getStream();
        $test = $this->getTest($node->getTemplateLine());
        $arguments = null;
        if ($stream->test(Token::PUNCTUATION_TYPE, '(')) {
            $arguments = $this->parseOnlyArguments();
        }
        elseif ($test->hasOneMandatoryArgument()) {
            $arguments = new Nodes([
                0 => $this->getPrimary(),
            ]);
        }
        if ('defined' === $test->getName() && $node instanceof NameExpression && null !== ($alias = $this->parser
            ->getImportedSymbol('function', $node->getAttribute('name')))) {
            $node = new MacroReferenceExpression($alias['node']->getNode('var'), $alias['name'], new ArrayExpression([], $node->getTemplateLine()), $node->getTemplateLine());
        }
        $ready = $test instanceof TwigTest;
        if (!isset($this->readyNodes[$class = $test->getNodeClass()])) {
            $this->readyNodes[$class] = (bool) (new \ReflectionClass($class))->getConstructor()
                ->getAttributes(FirstClassTwigCallableReady::class);
        }
        if (!($ready = $this->readyNodes[$class])) {
            trigger_deprecation('twig/twig', '3.12', 'Twig node "%s" is not marked as ready for passing a "TwigTest" in the constructor instead of its name; please update your code and then add #[FirstClassTwigCallableReady] attribute to the constructor.', $class);
        }
        return new $class($node, $ready ? $test : $test->getName(), $arguments, $this->parser
            ->getCurrentToken()
            ->getLine());
    }
    private function getTest(int $line) : TwigTest {
        $stream = $this->parser
            ->getStream();
        $name = $stream->expect(Token::NAME_TYPE)
            ->getValue();
        if ($stream->test(Token::NAME_TYPE)) {
            // try 2-words tests
            $name = $name . ' ' . $this->parser
                ->getCurrentToken()
                ->getValue();
            if ($test = $this->env
                ->getTest($name)) {
                $stream->next();
            }
        }
        else {
            $test = $this->env
                ->getTest($name);
        }
        if (!$test) {
            if ($this->parser
                ->shouldIgnoreUnknownTwigCallables()) {
                return new TwigTest($name, fn() => '');
            }
            $e = new SyntaxError(\sprintf('Unknown "%s" test.', $name), $line, $stream->getSourceContext());
            $e->addSuggestions($name, array_keys($this->env
                ->getTests()));
            throw $e;
        }
        if ($test->isDeprecated()) {
            $stream = $this->parser
                ->getStream();
            $src = $stream->getSourceContext();
            $test->triggerDeprecation($src->getPath() ?: $src->getName(), $stream->getCurrent()
                ->getLine());
        }
        return $test;
    }
    private function getFunction(string $name, int $line) : TwigFunction {
        if (!($function = $this->env
            ->getFunction($name))) {
            if ($this->parser
                ->shouldIgnoreUnknownTwigCallables()) {
                return new TwigFunction($name, fn() => '');
            }
            $e = new SyntaxError(\sprintf('Unknown "%s" function.', $name), $line, $this->parser
                ->getStream()
                ->getSourceContext());
            $e->addSuggestions($name, array_keys($this->env
                ->getFunctions()));
            throw $e;
        }
        if ($function->isDeprecated()) {
            $src = $this->parser
                ->getStream()
                ->getSourceContext();
            $function->triggerDeprecation($src->getPath() ?: $src->getName(), $line);
        }
        return $function;
    }
    private function getFilter(string $name, int $line) : TwigFilter {
        if (!($filter = $this->env
            ->getFilter($name))) {
            if ($this->parser
                ->shouldIgnoreUnknownTwigCallables()) {
                return new TwigFilter($name, fn() => '');
            }
            $e = new SyntaxError(\sprintf('Unknown "%s" filter.', $name), $line, $this->parser
                ->getStream()
                ->getSourceContext());
            $e->addSuggestions($name, array_keys($this->env
                ->getFilters()));
            throw $e;
        }
        if ($filter->isDeprecated()) {
            $src = $this->parser
                ->getStream()
                ->getSourceContext();
            $filter->triggerDeprecation($src->getPath() ?: $src->getName(), $line);
        }
        return $filter;
    }
    // checks that the node only contains "constant" elements
    // to be removed in 4.0
    private function checkConstantExpression(Node $node) : bool {
        if (!($node instanceof ConstantExpression || $node instanceof ArrayExpression || $node instanceof NegUnary || $node instanceof PosUnary)) {
            return false;
        }
        foreach ($node as $n) {
            if (!$this->checkConstantExpression($n)) {
                return false;
            }
        }
        return true;
    }
    private function setDeprecationCheck(bool $deprecationCheck) : bool {
        $current = $this->deprecationCheck;
        $this->deprecationCheck = $deprecationCheck;
        return $current;
    }
    private function createArguments(int $line) : ArrayExpression {
        $arguments = new ArrayExpression([], $line);
        foreach ($this->parseOnlyArguments() as $k => $n) {
            $arguments->addElement($n, new LocalVariable($k, $line));
        }
        return $arguments;
    }
    public function parseOnlyArguments() {
        $args = [];
        $stream = $this->parser
            ->getStream();
        $stream->expect(Token::PUNCTUATION_TYPE, '(', 'A list of arguments must begin with an opening parenthesis');
        $hasSpread = false;
        while (!$stream->test(Token::PUNCTUATION_TYPE, ')')) {
            if ($args) {
                $stream->expect(Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
                // if the comma above was a trailing comma, early exit the argument parse loop
                if ($stream->test(Token::PUNCTUATION_TYPE, ')')) {
                    break;
                }
            }
            if ($stream->nextIf(Token::SPREAD_TYPE)) {
                $hasSpread = true;
                $value = new SpreadUnary($this->parseExpression(), $stream->getCurrent()
                    ->getLine());
            }
            elseif ($hasSpread) {
                throw new SyntaxError('Normal arguments must be placed before argument unpacking.', $stream->getCurrent()
                    ->getLine(), $stream->getSourceContext());
            }
            else {
                $value = $this->parseExpression();
            }
            $name = null;
            if (($token = $stream->nextIf(Token::OPERATOR_TYPE, '=')) || ($token = $stream->nextIf(Token::PUNCTUATION_TYPE, ':'))) {
                if (!$value instanceof NameExpression) {
                    throw new SyntaxError(\sprintf('A parameter name must be a string, "%s" given.', \get_class($value)), $token->getLine(), $stream->getSourceContext());
                }
                $name = $value->getAttribute('name');
                $value = $this->parseExpression();
            }
            if (null === $name) {
                $args[] = $value;
            }
            else {
                $args[$name] = $value;
            }
        }
        $stream->expect(Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');
        return new Nodes($args);
    }
    private function parseSubscriptExpressionDot(Node $node) : AbstractExpression {
        $stream = $this->parser
            ->getStream();
        $token = $stream->getCurrent();
        $lineno = $token->getLine();
        $arguments = new ArrayExpression([], $lineno);
        $type = Template::ANY_CALL;
        if ($stream->nextIf(Token::PUNCTUATION_TYPE, '(')) {
            $attribute = $this->parseExpression();
            $stream->expect(Token::PUNCTUATION_TYPE, ')');
        }
        else {
            $token = $stream->next();
            if (Token::NAME_TYPE == $token->getType() || Token::NUMBER_TYPE == $token->getType() || Token::OPERATOR_TYPE == $token->getType() && preg_match(Lexer::REGEX_NAME, $token->getValue())) {
                $attribute = new ConstantExpression($token->getValue(), $token->getLine());
            }
            else {
                throw new SyntaxError(\sprintf('Expected name or number, got value "%s" of type %s.', $token->getValue(), Token::typeToEnglish($token->getType())), $token->getLine(), $stream->getSourceContext());
            }
        }
        if ($stream->test(Token::PUNCTUATION_TYPE, '(')) {
            $type = Template::METHOD_CALL;
            $arguments = $this->createArguments($token->getLine());
        }
        if ($node instanceof NameExpression && (null !== $this->parser
            ->getImportedSymbol('template', $node->getAttribute('name')) || '_self' === $node->getAttribute('name') && $attribute instanceof ConstantExpression)) {
            return new MacroReferenceExpression(new TemplateVariable($node->getAttribute('name'), $node->getTemplateLine()), 'macro_' . $attribute->getAttribute('value'), $arguments, $node->getTemplateLine());
        }
        return new GetAttrExpression($node, $attribute, $arguments, $type, $lineno);
    }
    private function parseSubscriptExpressionArray(Node $node) : AbstractExpression {
        $stream = $this->parser
            ->getStream();
        $token = $stream->getCurrent();
        $lineno = $token->getLine();
        $arguments = new ArrayExpression([], $lineno);
        // slice?
        $slice = false;
        if ($stream->test(Token::PUNCTUATION_TYPE, ':')) {
            $slice = true;
            $attribute = new ConstantExpression(0, $token->getLine());
        }
        else {
            $attribute = $this->parseExpression();
        }
        if ($stream->nextIf(Token::PUNCTUATION_TYPE, ':')) {
            $slice = true;
        }
        if ($slice) {
            if ($stream->test(Token::PUNCTUATION_TYPE, ']')) {
                $length = new ConstantExpression(null, $token->getLine());
            }
            else {
                $length = $this->parseExpression();
            }
            $filter = $this->getFilter('slice', $token->getLine());
            $arguments = new Nodes([
                $attribute,
                $length,
            ]);
            $filter = new $filter->getNodeClass()($node, $filter, $arguments, $token->getLine());
            $stream->expect(Token::PUNCTUATION_TYPE, ']');
            return $filter;
        }
        $stream->expect(Token::PUNCTUATION_TYPE, ']');
        return new GetAttrExpression($node, $attribute, $arguments, Template::ARRAY_CALL, $lineno);
    }

}