WB 2.08.x

<?php

/*

 * This file is part of Twig.

 *

 * (c) 2009 Fabien Potencier

 * (c) 2009 Armin Ronacher

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

/**

 * Lexes a template string.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 */

class Twig_Lexer implements Twig_LexerInterface

{

    protected $tokens;

    protected $code;

    protected $cursor;

    protected $lineno;

    protected $end;

    protected $state;

    protected $states;

    protected $brackets;

    protected $env;

    protected $filename;

    protected $options;

    protected $regexes;

    protected $position;

    protected $positions;

    protected $currentVarBlockLine;

    const STATE_DATA            = 0;

    const STATE_BLOCK           = 1;

    const STATE_VAR             = 2;

    const STATE_STRING          = 3;

    const STATE_INTERPOLATION   = 4;

    const REGEX_NAME            = '/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A';

    const REGEX_NUMBER          = '/[0-9]+(?:\.[0-9]+)?/A';

    const REGEX_STRING          = '/"([^#"\\\\]*(?:\\\\.[^#"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\'/As';

    const REGEX_DQ_STRING_DELIM = '/"/A';

    const REGEX_DQ_STRING_PART  = '/[^#"\\\\]*(?:(?:\\\\.|#(?!\{))[^#"\\\\]*)*/As';

    const PUNCTUATION           = '()[]{}?:.,|';

    public function __construct(Twig_Environment $env, array $options = array())

    {

        $this->env = $env;

        $this->options = array_merge(array(

            'tag_comment'     => array('{#', '#}'),

            'tag_block'       => array('{%', '%}'),

            'tag_variable'    => array('{{', '}}'),

            'whitespace_trim' => '-',

            'interpolation'   => array('#{', '}'),

        ), $options);

        $this->regexes = array(

            'lex_var'             => '/\s*'.preg_quote($this->options['whitespace_trim'].$this->options['tag_variable'][1], '/').'\s*|\s*'.preg_quote($this->options['tag_variable'][1], '/').'/A',

            'lex_block'           => '/\s*(?:'.preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '/').'\s*|\s*'.preg_quote($this->options['tag_block'][1], '/').')\n?/A',

            'lex_raw_data'        => '/('.preg_quote($this->options['tag_block'][0].$this->options['whitespace_trim'], '/').'|'.preg_quote($this->options['tag_block'][0], '/').')\s*(?:end%s)\s*(?:'.preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '/').'\s*|\s*'.preg_quote($this->options['tag_block'][1], '/').')/s',

            'operator'            => $this->getOperatorRegex(),

            'lex_comment'         => '/(?:'.preg_quote($this->options['whitespace_trim'], '/').preg_quote($this->options['tag_comment'][1], '/').'\s*|'.preg_quote($this->options['tag_comment'][1], '/').')\n?/s',

            'lex_block_raw'       => '/\s*(raw|verbatim)\s*(?:'.preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '/').'\s*|\s*'.preg_quote($this->options['tag_block'][1], '/').')/As',

            'lex_block_line'      => '/\s*line\s+(\d+)\s*'.preg_quote($this->options['tag_block'][1], '/').'/As',

            'lex_tokens_start'    => '/('.preg_quote($this->options['tag_variable'][0], '/').'|'.preg_quote($this->options['tag_block'][0], '/').'|'.preg_quote($this->options['tag_comment'][0], '/').')('.preg_quote($this->options['whitespace_trim'], '/').')?/s',

            'interpolation_start' => '/'.preg_quote($this->options['interpolation'][0], '/').'\s*/A',

            'interpolation_end'   => '/\s*'.preg_quote($this->options['interpolation'][1], '/').'/A',

        );

    }

    /**

     * Tokenizes a source code.

     *

     * @param string $code     The source code

     * @param string $filename A unique identifier for the source code

     *

     * @return Twig_TokenStream A token stream instance

     */

    public function tokenize($code, $filename = null)

    {

        if (function_exists('mb_internal_encoding') && ((int) ini_get('mbstring.func_overload')) & 2) {

            $mbEncoding = mb_internal_encoding();

            mb_internal_encoding('ASCII');

        }

        $this->code = str_replace(array("\r\n", "\r"), "\n", $code);

        $this->filename = $filename;

        $this->cursor = 0;

        $this->lineno = 1;

        $this->end = strlen($this->code);

        $this->tokens = array();

        $this->state = self::STATE_DATA;

        $this->states = array();

        $this->brackets = array();

        $this->position = -1;

        // find all token starts in one go

        preg_match_all($this->regexes['lex_tokens_start'], $this->code, $matches, PREG_OFFSET_CAPTURE);

        $this->positions = $matches;

        while ($this->cursor < $this->end) {

            // dispatch to the lexing functions depending

            // on the current state

            switch ($this->state) {

                case self::STATE_DATA:

                    $this->lexData();

                    break;

                case self::STATE_BLOCK:

                    $this->lexBlock();

                    break;

                case self::STATE_VAR:

                    $this->lexVar();

                    break;

                case self::STATE_STRING:

                    $this->lexString();

                    break;

                case self::STATE_INTERPOLATION:

                    $this->lexInterpolation();

                    break;

            }

        }

        $this->pushToken(Twig_Token::EOF_TYPE);

        if (!empty($this->brackets)) {

            list($expect, $lineno) = array_pop($this->brackets);

            throw new Twig_Error_Syntax(sprintf('Unclosed "%s"', $expect), $lineno, $this->filename);

        }

        if (isset($mbEncoding)) {

            mb_internal_encoding($mbEncoding);

        }

        return new Twig_TokenStream($this->tokens, $this->filename);

    }

    protected function lexData()

    {

        // if no matches are left we return the rest of the template as simple text token

        if ($this->position == count($this->positions[0]) - 1) {

            $this->pushToken(Twig_Token::TEXT_TYPE, substr($this->code, $this->cursor));

            $this->cursor = $this->end;

            return;

        }

        // Find the first token after the current cursor

        $position = $this->positions[0][++$this->position];

        while ($position[1] < $this->cursor) {

            if ($this->position == count($this->positions[0]) - 1) {

                return;

            }

            $position = $this->positions[0][++$this->position];

        }

        // push the template text first

        $text = $textContent = substr($this->code, $this->cursor, $position[1] - $this->cursor);

        if (isset($this->positions[2][$this->position][0])) {

            $text = rtrim($text);

        }

        $this->pushToken(Twig_Token::TEXT_TYPE, $text);

        $this->moveCursor($textContent.$position[0]);

        switch ($this->positions[1][$this->position][0]) {

            case $this->options['tag_comment'][0]:

                $this->lexComment();

                break;

            case $this->options['tag_block'][0]:

                // raw data?

                if (preg_match($this->regexes['lex_block_raw'], $this->code, $match, null, $this->cursor)) {

                    $this->moveCursor($match[0]);

                    $this->lexRawData($match[1]);

                // {% line \d+ %}

                } elseif (preg_match($this->regexes['lex_block_line'], $this->code, $match, null, $this->cursor)) {

                    $this->moveCursor($match[0]);

                    $this->lineno = (int) $match[1];

                } else {

                    $this->pushToken(Twig_Token::BLOCK_START_TYPE);

                    $this->pushState(self::STATE_BLOCK);

                    $this->currentVarBlockLine = $this->lineno;

                }

                break;

            case $this->options['tag_variable'][0]:

                $this->pushToken(Twig_Token::VAR_START_TYPE);

                $this->pushState(self::STATE_VAR);

                $this->currentVarBlockLine = $this->lineno;

                break;

        }

    }

    protected function lexBlock()

    {

        if (empty($this->brackets) && preg_match($this->regexes['lex_block'], $this->code, $match, null, $this->cursor)) {

            $this->pushToken(Twig_Token::BLOCK_END_TYPE);

            $this->moveCursor($match[0]);

            $this->popState();

        } else {

            $this->lexExpression();

        }

    }

    protected function lexVar()

    {

        if (empty($this->brackets) && preg_match($this->regexes['lex_var'], $this->code, $match, null, $this->cursor)) {

            $this->pushToken(Twig_Token::VAR_END_TYPE);

            $this->moveCursor($match[0]);

            $this->popState();

        } else {

            $this->lexExpression();

        }

    }

    protected function lexExpression()

    {

        // whitespace

        if (preg_match('/\s+/A', $this->code, $match, null, $this->cursor)) {

            $this->moveCursor($match[0]);

            if ($this->cursor >= $this->end) {

                throw new Twig_Error_Syntax(sprintf('Unclosed "%s"', $this->state === self::STATE_BLOCK ? 'block' : 'variable'), $this->currentVarBlockLine, $this->filename);

            }

        }

        // operators

        if (preg_match($this->regexes['operator'], $this->code, $match, null, $this->cursor)) {

            $this->pushToken(Twig_Token::OPERATOR_TYPE, $match[0]);

            $this->moveCursor($match[0]);

        }

        // names

        elseif (preg_match(self::REGEX_NAME, $this->code, $match, null, $this->cursor)) {

            $this->pushToken(Twig_Token::NAME_TYPE, $match[0]);

            $this->moveCursor($match[0]);

        }

        // numbers

        elseif (preg_match(self::REGEX_NUMBER, $this->code, $match, null, $this->cursor)) {

            $number = (float) $match[0];  // floats

            if (ctype_digit($match[0]) && $number <= PHP_INT_MAX) {

                $number = (int) $match[0]; // integers lower than the maximum

            }

            $this->pushToken(Twig_Token::NUMBER_TYPE, $number);

            $this->moveCursor($match[0]);

        }

        // punctuation

        elseif (false !== strpos(self::PUNCTUATION, $this->code[$this->cursor])) {

            // opening bracket

            if (false !== strpos('([{', $this->code[$this->cursor])) {

                $this->brackets[] = array($this->code[$this->cursor], $this->lineno);

            }

            // closing bracket

            elseif (false !== strpos(')]}', $this->code[$this->cursor])) {

                if (empty($this->brackets)) {

                    throw new Twig_Error_Syntax(sprintf('Unexpected "%s"', $this->code[$this->cursor]), $this->lineno, $this->filename);

                }

                list($expect, $lineno) = array_pop($this->brackets);

                if ($this->code[$this->cursor] != strtr($expect, '([{', ')]}')) {

                    throw new Twig_Error_Syntax(sprintf('Unclosed "%s"', $expect), $lineno, $this->filename);

                }

            }

            $this->pushToken(Twig_Token::PUNCTUATION_TYPE, $this->code[$this->cursor]);

            ++$this->cursor;

        }

        // strings

        elseif (preg_match(self::REGEX_STRING, $this->code, $match, null, $this->cursor)) {

            $this->pushToken(Twig_Token::STRING_TYPE, stripcslashes(substr($match[0], 1, -1)));

            $this->moveCursor($match[0]);

        }

        // opening double quoted string

        elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, null, $this->cursor)) {

            $this->brackets[] = array('"', $this->lineno);

            $this->pushState(self::STATE_STRING);

            $this->moveCursor($match[0]);

        }

        // unlexable

        else {

            throw new Twig_Error_Syntax(sprintf('Unexpected character "%s"', $this->code[$this->cursor]), $this->lineno, $this->filename);

        }

    }

    protected function lexRawData($tag)

    {

        if (!preg_match(str_replace('%s', $tag, $this->regexes['lex_raw_data']), $this->code, $match, PREG_OFFSET_CAPTURE, $this->cursor)) {

            throw new Twig_Error_Syntax(sprintf('Unexpected end of file: Unclosed "%s" block', $tag), $this->lineno, $this->filename);

        }

        $text = substr($this->code, $this->cursor, $match[0][1] - $this->cursor);

        $this->moveCursor($text.$match[0][0]);

        if (false !== strpos($match[1][0], $this->options['whitespace_trim'])) {

            $text = rtrim($text);

        }

        $this->pushToken(Twig_Token::TEXT_TYPE, $text);

    }

    protected function lexComment()

    {

        if (!preg_match($this->regexes['lex_comment'], $this->code, $match, PREG_OFFSET_CAPTURE, $this->cursor)) {

            throw new Twig_Error_Syntax('Unclosed comment', $this->lineno, $this->filename);

        }

        $this->moveCursor(substr($this->code, $this->cursor, $match[0][1] - $this->cursor).$match[0][0]);

    }

    protected function lexString()

    {

        if (preg_match($this->regexes['interpolation_start'], $this->code, $match, null, $this->cursor)) {

            $this->brackets[] = array($this->options['interpolation'][0], $this->lineno);

            $this->pushToken(Twig_Token::INTERPOLATION_START_TYPE);

            $this->moveCursor($match[0]);

            $this->pushState(self::STATE_INTERPOLATION);

        } elseif (preg_match(self::REGEX_DQ_STRING_PART, $this->code, $match, null, $this->cursor) && strlen($match[0]) > 0) {

            $this->pushToken(Twig_Token::STRING_TYPE, stripcslashes($match[0]));

            $this->moveCursor($match[0]);

        } elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, null, $this->cursor)) {

            list($expect, $lineno) = array_pop($this->brackets);

            if ($this->code[$this->cursor] != '"') {

                throw new Twig_Error_Syntax(sprintf('Unclosed "%s"', $expect), $lineno, $this->filename);

            }

            $this->popState();

            ++$this->cursor;

        }

    }

    protected function lexInterpolation()

    {

        $bracket = end($this->brackets);

        if ($this->options['interpolation'][0] === $bracket[0] && preg_match($this->regexes['interpolation_end'], $this->code, $match, null, $this->cursor)) {

            array_pop($this->brackets);

            $this->pushToken(Twig_Token::INTERPOLATION_END_TYPE);

            $this->moveCursor($match[0]);

            $this->popState();

        } else {

            $this->lexExpression();

        }

    }

    protected function pushToken($type, $value = '')

    {

        // do not push empty text tokens

        if (Twig_Token::TEXT_TYPE === $type && '' === $value) {

            return;

        }

        $this->tokens[] = new Twig_Token($type, $value, $this->lineno);

    }

    protected function moveCursor($text)

    {

        $this->cursor += strlen($text);

        $this->lineno += substr_count($text, "\n");

    }

    protected function getOperatorRegex()

    {

        $operators = array_merge(

            array('='),

            array_keys($this->env->getUnaryOperators()),

            array_keys($this->env->getBinaryOperators())

        );

        $operators = array_combine($operators, array_map('strlen', $operators));

        arsort($operators);

        $regex = array();

        foreach ($operators as $operator => $length) {

            // an operator that ends with a character must be followed by

            // a whitespace or a parenthesis

            if (ctype_alpha($operator[$length - 1])) {

                $regex[] = preg_quote($operator, '/').'(?=[\s()])';

            } else {

                $regex[] = preg_quote($operator, '/');

            }

        }

        return '/'.implode('|', $regex).'/A';

    }

    protected function pushState($state)

    {

        $this->states[] = $this->state;

        $this->state = $state;

    }

    protected function popState()

    {

        if (0 === count($this->states)) {

            throw new Exception('Cannot pop state without a previous state');

        }

        $this->state = array_pop($this->states);

    }

}