vendor/twig/twig/src/Lexer.php line 431

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  1. <?php
  3. /*
  4.  * This file is part of Twig.
  5.  *
  6.  * (c) Fabien Potencier
  7.  * (c) Armin Ronacher
  8.  *
  9.  * For the full copyright and license information, please view the LICENSE
  10.  * file that was distributed with this source code.
  11.  */
  13. namespace Twig;
  15. use Twig\Error\SyntaxError;
  16. use Twig\ExpressionParser\ExpressionParsers;
  18. /**
  19.  * @author Fabien Potencier <fabien@symfony.com>
  20.  */
  21. class Lexer
  22. {
  23.     private $isInitialized = false;
  25.     private $tokens;
  26.     private $code;
  27.     private $cursor;
  28.     private $lineno;
  29.     private $end;
  30.     private $state;
  31.     private $states;
  32.     private $brackets;
  33.     private $env;
  34.     private $source;
  35.     private $options;
  36.     private $regexes;
  37.     private $position;
  38.     private $positions;
  39.     private $currentVarBlockLine;
  40.     private array $openingBrackets = ['{', '(', '['];
  41.     private array $closingBrackets = ['}', ')', ']'];
  43.     public const STATE_DATA = 0;
  44.     public const STATE_BLOCK = 1;
  45.     public const STATE_VAR = 2;
  46.     public const STATE_STRING = 3;
  47.     public const STATE_INTERPOLATION = 4;
  49.     public const REGEX_NAME = '/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A';
  50.     public const REGEX_STRING = '/"([^#"\\\\]*(?:\\\\.[^#"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\'/As';
  52.     public const REGEX_NUMBER = '/(?(DEFINE)
  53.         (?<LNUM>[0-9]+(_[0-9]+)*)               # Integers (with underscores)   123_456
  54.         (?<FRAC>\.(?&LNUM))                     # Fractional part               .456
  55.         (?<EXPONENT>[eE][+-]?(?&LNUM))          # Exponent part                 E+10
  56.         (?<DNUM>(?&LNUM)(?:(?&FRAC))?)          # Decimal number                123_456.456
  57.     )(?:(?&DNUM)(?:(?&EXPONENT))?)              #                               123_456.456E+10
  58.     /Ax';
  60.     public const REGEX_DQ_STRING_DELIM = '/"/A';
  61.     public const REGEX_DQ_STRING_PART = '/[^#"\\\\]*(?:(?:\\\\.|#(?!\{))[^#"\\\\]*)*/As';
  62.     public const REGEX_INLINE_COMMENT = '/#[^\n]*/A';
  63.     public const PUNCTUATION = '()[]{}?:.,|';
  65.     private const SPECIAL_CHARS = [
  66.         'f' => "\f",
  67.         'n' => "\n",
  68.         'r' => "\r",
  69.         't' => "\t",
  70.         'v' => "\v",
  71.     ];
  73.     public function __construct(Environment $env, array $options = [])
  74.     {
  75.         $this->env = $env;
  77.         $this->options = array_merge([
  78.             'tag_comment' => ['{#', '#}'],
  79.             'tag_block' => ['{%', '%}'],
  80.             'tag_variable' => ['{{', '}}'],
  81.             'whitespace_trim' => '-',
  82.             'whitespace_line_trim' => '~',
  83.             'whitespace_line_chars' => ' \t\0\x0B',
  84.             'interpolation' => ['#{', '}'],
  85.         ], $options);
  86.     }
  88.     private function initialize(): void
  89.     {
  90.         if ($this->isInitialized) {
  91.             return;
  92.         }
  94.         // when PHP 7.3 is the min version, we will be able to remove the '#' part in preg_quote as it's part of the default
  95.         $this->regexes = [
  96.             // }}
  97.             'lex_var' => '{
  98.                 \s*
  99.                 (?:'.
  100.                     preg_quote($this->options['whitespace_trim'].$this->options['tag_variable'][1], '#').'\s*'. // -}}\s*
  101.                     '|'.
  102.                     preg_quote($this->options['whitespace_line_trim'].$this->options['tag_variable'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~}}[ \t\0\x0B]*
  103.                     '|'.
  104.                     preg_quote($this->options['tag_variable'][1], '#'). // }}
  105.                 ')
  106.             }Ax',
  108.             // %}
  109.             'lex_block' => '{
  110.                 \s*
  111.                 (?:'.
  112.                     preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '#').'\s*\n?'. // -%}\s*\n?
  113.                     '|'.
  114.                     preg_quote($this->options['whitespace_line_trim'].$this->options['tag_block'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~%}[ \t\0\x0B]*
  115.                     '|'.
  116.                     preg_quote($this->options['tag_block'][1], '#').'\n?'. // %}\n?
  117.                 ')
  118.             }Ax',
  120.             // {% endverbatim %}
  121.             'lex_raw_data' => '{'.
  122.                 preg_quote($this->options['tag_block'][0], '#'). // {%
  123.                 '('.
  124.                     $this->options['whitespace_trim']. // -
  125.                     '|'.
  126.                     $this->options['whitespace_line_trim']. // ~
  127.                 ')?\s*endverbatim\s*'.
  128.                 '(?:'.
  129.                     preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '#').'\s*'. // -%}
  130.                     '|'.
  131.                     preg_quote($this->options['whitespace_line_trim'].$this->options['tag_block'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~%}[ \t\0\x0B]*
  132.                     '|'.
  133.                     preg_quote($this->options['tag_block'][1], '#'). // %}
  134.                 ')
  135.             }sx',
  137.             'operator' => $this->getOperatorRegex(),
  139.             // #}
  140.             'lex_comment' => '{
  141.                 (?:'.
  142.                     preg_quote($this->options['whitespace_trim'].$this->options['tag_comment'][1], '#').'\s*\n?'. // -#}\s*\n?
  143.                     '|'.
  144.                     preg_quote($this->options['whitespace_line_trim'].$this->options['tag_comment'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~#}[ \t\0\x0B]*
  145.                     '|'.
  146.                     preg_quote($this->options['tag_comment'][1], '#').'\n?'. // #}\n?
  147.                 ')
  148.             }sx',
  150.             // verbatim %}
  151.             'lex_block_raw' => '{
  152.                 \s*verbatim\s*
  153.                 (?:'.
  154.                     preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '#').'\s*'. // -%}\s*
  155.                     '|'.
  156.                     preg_quote($this->options['whitespace_line_trim'].$this->options['tag_block'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~%}[ \t\0\x0B]*
  157.                     '|'.
  158.                     preg_quote($this->options['tag_block'][1], '#'). // %}
  159.                 ')
  160.             }Asx',
  162.             'lex_block_line' => '{\s*line\s+(\d+)\s*'.preg_quote($this->options['tag_block'][1], '#').'}As',
  164.             // {{ or {% or {#
  165.             'lex_tokens_start' => '{
  166.                 ('.
  167.                     preg_quote($this->options['tag_variable'][0], '#'). // {{
  168.                     '|'.
  169.                     preg_quote($this->options['tag_block'][0], '#'). // {%
  170.                     '|'.
  171.                     preg_quote($this->options['tag_comment'][0], '#'). // {#
  172.                 ')('.
  173.                     preg_quote($this->options['whitespace_trim'], '#'). // -
  174.                     '|'.
  175.                     preg_quote($this->options['whitespace_line_trim'], '#'). // ~
  176.                 ')?
  177.             }sx',
  178.             'interpolation_start' => '{'.preg_quote($this->options['interpolation'][0], '#').'\s*}A',
  179.             'interpolation_end' => '{\s*'.preg_quote($this->options['interpolation'][1], '#').'}A',
  180.         ];
  182.         $this->isInitialized = true;
  183.     }
  185.     public function tokenize(Source $source): TokenStream
  186.     {
  187.         $this->initialize();
  189.         $this->source = $source;
  190.         $this->code = str_replace(["\r\n", "\r"], "\n", $source->getCode());
  191.         $this->cursor = 0;
  192.         $this->lineno = 1;
  193.         $this->end = \strlen($this->code);
  194.         $this->tokens = [];
  195.         $this->state = self::STATE_DATA;
  196.         $this->states = [];
  197.         $this->brackets = [];
  198.         $this->position = -1;
  200.         // find all token starts in one go
  201.         preg_match_all($this->regexes['lex_tokens_start'], $this->code, $matches, \PREG_OFFSET_CAPTURE);
  202.         $this->positions = $matches;
  204.         while ($this->cursor < $this->end) {
  205.             // dispatch to the lexing functions depending
  206.             // on the current state
  207.             switch ($this->state) {
  208.                 case self::STATE_DATA:
  209.                     $this->lexData();
  210.                     break;
  212.                 case self::STATE_BLOCK:
  213.                     $this->lexBlock();
  214.                     break;
  216.                 case self::STATE_VAR:
  217.                     $this->lexVar();
  218.                     break;
  220.                 case self::STATE_STRING:
  221.                     $this->lexString();
  222.                     break;
  224.                 case self::STATE_INTERPOLATION:
  225.                     $this->lexInterpolation();
  226.                     break;
  227.             }
  228.         }
  230.         $this->pushToken(Token::EOF_TYPE);
  232.         if ($this->brackets) {
  233.             [$expect, $lineno] = array_pop($this->brackets);
  234.             throw new SyntaxError(\sprintf('Unclosed "%s".', $expect), $lineno, $this->source);
  235.         }
  237.         return new TokenStream($this->tokens, $this->source);
  238.     }
  240.     private function lexData(): void
  241.     {
  242.         // if no matches are left we return the rest of the template as simple text token
  243.         if ($this->position == \count($this->positions[0]) - 1) {
  244.             $this->pushToken(Token::TEXT_TYPE, substr($this->code, $this->cursor));
  245.             $this->cursor = $this->end;
  247.             return;
  248.         }
  250.         // Find the first token after the current cursor
  251.         $position = $this->positions[0][++$this->position];
  252.         while ($position[1] < $this->cursor) {
  253.             if ($this->position == \count($this->positions[0]) - 1) {
  254.                 return;
  255.             }
  256.             $position = $this->positions[0][++$this->position];
  257.         }
  259.         // push the template text first
  260.         $text = $textContent = substr($this->code, $this->cursor, $position[1] - $this->cursor);
  262.         // trim?
  263.         if (isset($this->positions[2][$this->position][0])) {
  264.             if ($this->options['whitespace_trim'] === $this->positions[2][$this->position][0]) {
  265.                 // whitespace_trim detected ({%-, {{- or {#-)
  266.                 $text = rtrim($text);
  267.             } elseif ($this->options['whitespace_line_trim'] === $this->positions[2][$this->position][0]) {
  268.                 // whitespace_line_trim detected ({%~, {{~ or {#~)
  269.                 // don't trim \r and \n
  270.                 $text = rtrim($text, " \t\0\x0B");
  271.             }
  272.         }
  273.         $this->pushToken(Token::TEXT_TYPE, $text);
  274.         $this->moveCursor($textContent.$position[0]);
  276.         switch ($this->positions[1][$this->position][0]) {
  277.             case $this->options['tag_comment'][0]:
  278.                 $this->lexComment();
  279.                 break;
  281.             case $this->options['tag_block'][0]:
  282.                 // raw data?
  283.                 if (preg_match($this->regexes['lex_block_raw'], $this->code, $match, 0, $this->cursor)) {
  284.                     $this->moveCursor($match[0]);
  285.                     $this->lexRawData();
  286.                 // {% line \d+ %}
  287.                 } elseif (preg_match($this->regexes['lex_block_line'], $this->code, $match, 0, $this->cursor)) {
  288.                     $this->moveCursor($match[0]);
  289.                     $this->lineno = (int) $match[1];
  290.                 } else {
  291.                     $this->pushToken(Token::BLOCK_START_TYPE);
  292.                     $this->pushState(self::STATE_BLOCK);
  293.                     $this->currentVarBlockLine = $this->lineno;
  294.                 }
  295.                 break;
  297.             case $this->options['tag_variable'][0]:
  298.                 $this->pushToken(Token::VAR_START_TYPE);
  299.                 $this->pushState(self::STATE_VAR);
  300.                 $this->currentVarBlockLine = $this->lineno;
  301.                 break;
  302.         }
  303.     }
  305.     private function lexBlock(): void
  306.     {
  307.         if (!$this->brackets && preg_match($this->regexes['lex_block'], $this->code, $match, 0, $this->cursor)) {
  308.             $this->pushToken(Token::BLOCK_END_TYPE);
  309.             $this->moveCursor($match[0]);
  310.             $this->popState();
  311.         } else {
  312.             $this->lexExpression();
  313.         }
  314.     }
  316.     private function lexVar(): void
  317.     {
  318.         if (!$this->brackets && preg_match($this->regexes['lex_var'], $this->code, $match, 0, $this->cursor)) {
  319.             $this->pushToken(Token::VAR_END_TYPE);
  320.             $this->moveCursor($match[0]);
  321.             $this->popState();
  322.         } else {
  323.             $this->lexExpression();
  324.         }
  325.     }
  327.     private function lexExpression(): void
  328.     {
  329.         // whitespace
  330.         if (preg_match('/\s+/A', $this->code, $match, 0, $this->cursor)) {
  331.             $this->moveCursor($match[0]);
  333.             if ($this->cursor >= $this->end) {
  334.                 throw new SyntaxError(\sprintf('Unclosed "%s".', self::STATE_BLOCK === $this->state ? 'block' : 'variable'), $this->currentVarBlockLine, $this->source);
  335.             }
  336.         }
  338.         // operators
  339.         if (preg_match($this->regexes['operator'], $this->code, $match, 0, $this->cursor)) {
  340.             $operator = preg_replace('/\s+/', ' ', $match[0]);
  341.             if (\in_array($operator, $this->openingBrackets, true)) {
  342.                 $this->checkBrackets($operator);
  343.             }
  344.             $this->pushToken(Token::OPERATOR_TYPE, $operator);
  345.             $this->moveCursor($match[0]);
  346.         }
  347.         // names
  348.         elseif (preg_match(self::REGEX_NAME, $this->code, $match, 0, $this->cursor)) {
  349.             $this->pushToken(Token::NAME_TYPE, $match[0]);
  350.             $this->moveCursor($match[0]);
  351.         }
  352.         // numbers
  353.         elseif (preg_match(self::REGEX_NUMBER, $this->code, $match, 0, $this->cursor)) {
  354.             $this->pushToken(Token::NUMBER_TYPE, 0 + str_replace('_', '', $match[0]));
  355.             $this->moveCursor($match[0]);
  356.         }
  357.         // punctuation
  358.         elseif (str_contains(self::PUNCTUATION, $this->code[$this->cursor])) {
  359.             $this->checkBrackets($this->code[$this->cursor]);
  360.             $this->pushToken(Token::PUNCTUATION_TYPE, $this->code[$this->cursor]);
  361.             ++$this->cursor;
  362.         }
  363.         // strings
  364.         elseif (preg_match(self::REGEX_STRING, $this->code, $match, 0, $this->cursor)) {
  365.             $this->pushToken(Token::STRING_TYPE, $this->stripcslashes(substr($match[0], 1, -1), substr($match[0], 0, 1)));
  366.             $this->moveCursor($match[0]);
  367.         }
  368.         // opening double quoted string
  369.         elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, 0, $this->cursor)) {
  370.             $this->brackets[] = ['"', $this->lineno];
  371.             $this->pushState(self::STATE_STRING);
  372.             $this->moveCursor($match[0]);
  373.         }
  374.         // inline comment
  375.         elseif (preg_match(self::REGEX_INLINE_COMMENT, $this->code, $match, 0, $this->cursor)) {
  376.             $this->moveCursor($match[0]);
  377.         }
  378.         // unlexable
  379.         else {
  380.             throw new SyntaxError(\sprintf('Unexpected character "%s".', $this->code[$this->cursor]), $this->lineno, $this->source);
  381.         }
  382.     }
  384.     private function stripcslashes(string $str, string $quoteType): string
  385.     {
  386.         $result = '';
  387.         $length = \strlen($str);
  389.         $i = 0;
  390.         while ($i < $length) {
  391.             if (false === $pos = strpos($str, '\\', $i)) {
  392.                 $result .= substr($str, $i);
  393.                 break;
  394.             }
  396.             $result .= substr($str, $i, $pos - $i);
  397.             $i = $pos + 1;
  399.             if ($i >= $length) {
  400.                 $result .= '\\';
  401.                 break;
  402.             }
  404.             $nextChar = $str[$i];
  406.             if (isset(self::SPECIAL_CHARS[$nextChar])) {
  407.                 $result .= self::SPECIAL_CHARS[$nextChar];
  408.             } elseif ('\\' === $nextChar) {
  409.                 $result .= $nextChar;
  410.             } elseif ("'" === $nextChar || '"' === $nextChar) {
  411.                 if ($nextChar !== $quoteType) {
  412.                     trigger_deprecation('twig/twig', '3.12', 'Character "%s" should not be escaped; the "\" character is ignored in Twig 3 but will not be in Twig 4. Please remove the extra "\" character at position %d in "%s" at line %d.', $nextChar, $i + 1, $this->source->getName(), $this->lineno);
  413.                 }
  414.                 $result .= $nextChar;
  415.             } elseif ('#' === $nextChar && $i + 1 < $length && '{' === $str[$i + 1]) {
  416.                 $result .= '#{';
  417.                 ++$i;
  418.             } elseif ('x' === $nextChar && $i + 1 < $length && ctype_xdigit($str[$i + 1])) {
  419.                 $hex = $str[++$i];
  420.                 if ($i + 1 < $length && ctype_xdigit($str[$i + 1])) {
  421.                     $hex .= $str[++$i];
  422.                 }
  423.                 $result .= \chr(hexdec($hex));
  424.             } elseif (ctype_digit($nextChar) && $nextChar < '8') {
  425.                 $octal = $nextChar;
  426.                 while ($i + 1 < $length && ctype_digit($str[$i + 1]) && $str[$i + 1] < '8' && \strlen($octal) < 3) {
  427.                     $octal .= $str[++$i];
  428.                 }
  429.                 $result .= \chr(octdec($octal));
  430.             } else {
  431.                 trigger_deprecation('twig/twig', '3.12', 'Character "%s" should not be escaped; the "\" character is ignored in Twig 3 but will not be in Twig 4. Please remove the extra "\" character at position %d in "%s" at line %d.', $nextChar, $i + 1, $this->source->getName(), $this->lineno);
  432.                 $result .= $nextChar;
  433.             }
  435.             ++$i;
  436.         }
  438.         return $result;
  439.     }
  441.     private function lexRawData(): void
  442.     {
  443.         if (!preg_match($this->regexes['lex_raw_data'], $this->code, $match, \PREG_OFFSET_CAPTURE, $this->cursor)) {
  444.             throw new SyntaxError('Unexpected end of file: Unclosed "verbatim" block.', $this->lineno, $this->source);
  445.         }
  447.         $text = substr($this->code, $this->cursor, $match[0][1] - $this->cursor);
  448.         $this->moveCursor($text.$match[0][0]);
  450.         // trim?
  451.         if (isset($match[1][0])) {
  452.             if ($this->options['whitespace_trim'] === $match[1][0]) {
  453.                 // whitespace_trim detected ({%-, {{- or {#-)
  454.                 $text = rtrim($text);
  455.             } else {
  456.                 // whitespace_line_trim detected ({%~, {{~ or {#~)
  457.                 // don't trim \r and \n
  458.                 $text = rtrim($text, " \t\0\x0B");
  459.             }
  460.         }
  462.         $this->pushToken(Token::TEXT_TYPE, $text);
  463.     }
  465.     private function lexComment(): void
  466.     {
  467.         if (!preg_match($this->regexes['lex_comment'], $this->code, $match, \PREG_OFFSET_CAPTURE, $this->cursor)) {
  468.             throw new SyntaxError('Unclosed comment.', $this->lineno, $this->source);
  469.         }
  471.         $this->moveCursor(substr($this->code, $this->cursor, $match[0][1] - $this->cursor).$match[0][0]);
  472.     }
  474.     private function lexString(): void
  475.     {
  476.         if (preg_match($this->regexes['interpolation_start'], $this->code, $match, 0, $this->cursor)) {
  477.             $this->brackets[] = [$this->options['interpolation'][0], $this->lineno];
  478.             $this->pushToken(Token::INTERPOLATION_START_TYPE);
  479.             $this->moveCursor($match[0]);
  480.             $this->pushState(self::STATE_INTERPOLATION);
  481.         } elseif (preg_match(self::REGEX_DQ_STRING_PART, $this->code, $match, 0, $this->cursor) && '' !== $match[0]) {
  482.             $this->pushToken(Token::STRING_TYPE, $this->stripcslashes($match[0], '"'));
  483.             $this->moveCursor($match[0]);
  484.         } elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, 0, $this->cursor)) {
  485.             [$expect, $lineno] = array_pop($this->brackets);
  486.             if ('"' != $this->code[$this->cursor]) {
  487.                 throw new SyntaxError(\sprintf('Unclosed "%s".', $expect), $lineno, $this->source);
  488.             }
  490.             $this->popState();
  491.             ++$this->cursor;
  492.         } else {
  493.             // unlexable
  494.             throw new SyntaxError(\sprintf('Unexpected character "%s".', $this->code[$this->cursor]), $this->lineno, $this->source);
  495.         }
  496.     }
  498.     private function lexInterpolation(): void
  499.     {
  500.         $bracket = end($this->brackets);
  501.         if ($this->options['interpolation'][0] === $bracket[0] && preg_match($this->regexes['interpolation_end'], $this->code, $match, 0, $this->cursor)) {
  502.             array_pop($this->brackets);
  503.             $this->pushToken(Token::INTERPOLATION_END_TYPE);
  504.             $this->moveCursor($match[0]);
  505.             $this->popState();
  506.         } else {
  507.             $this->lexExpression();
  508.         }
  509.     }
  511.     private function pushToken($type, $value = ''): void
  512.     {
  513.         // do not push empty text tokens
  514.         if (Token::TEXT_TYPE === $type && '' === $value) {
  515.             return;
  516.         }
  518.         $this->tokens[] = new Token($type, $value, $this->lineno);
  519.     }
  521.     private function moveCursor($text): void
  522.     {
  523.         $this->cursor += \strlen($text);
  524.         $this->lineno += substr_count($text, "\n");
  525.     }
  527.     private function getOperatorRegex(): string
  528.     {
  529.         $expressionParsers = [];
  530.         foreach ($this->env->getExpressionParsers() as $expressionParser) {
  531.             $expressionParsers = array_merge($expressionParsers, ExpressionParsers::getOperatorTokensFor($expressionParser));
  532.         }
  534.         $expressionParsers = array_combine($expressionParsers, array_map('strlen', $expressionParsers));
  535.         arsort($expressionParsers);
  537.         $regex = [];
  538.         foreach ($expressionParsers as $expressionParser => $length) {
  539.             // an operator that ends with a character must be followed by
  540.             // a whitespace, a parenthesis, an opening map [ or sequence {
  541.             $r = preg_quote($expressionParser, '/');
  542.             if (ctype_alpha($expressionParser[$length - 1])) {
  543.                 $r .= '(?=[\s()\[{])';
  544.             }
  546.             // an operator that begins with a character must not have a dot or pipe before
  547.             if (ctype_alpha($expressionParser[0])) {
  548.                 $r = '(?<![\.\|]\s|.[\.\|])'.$r;
  549.             }
  551.             // an operator with a space can be any amount of whitespaces
  552.             $r = preg_replace('/\s+/', '\s+', $r);
  554.             $regex[] = $r;
  555.         }
  557.         return '/'.implode('|', $regex).'/A';
  558.     }
  560.     private function pushState($state): void
  561.     {
  562.         $this->states[] = $this->state;
  563.         $this->state = $state;
  564.     }
  566.     private function popState(): void
  567.     {
  568.         if (0 === \count($this->states)) {
  569.             throw new \LogicException('Cannot pop state without a previous state.');
  570.         }
  572.         $this->state = array_pop($this->states);
  573.     }
  575.     private function checkBrackets(string $code): void
  576.     {
  577.         // opening bracket
  578.         if (\in_array($code, $this->openingBrackets, true)) {
  579.             $this->brackets[] = [$code, $this->lineno];
  580.         } elseif (\in_array($code, $this->closingBrackets, true)) {
  581.             // closing bracket
  582.             if (!$this->brackets) {
  583.                 throw new SyntaxError(\sprintf('Unexpected "%s".', $code), $this->lineno, $this->source);
  584.             }
  586.             [$expect, $lineno] = array_pop($this->brackets);
  587.             if ($code !== str_replace($this->openingBrackets, $this->closingBrackets, $expect)) {
  588.                 throw new SyntaxError(\sprintf('Unclosed "%s".', $expect), $lineno, $this->source);
  589.             }
  590.         }
  591.     }
  592. }