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<?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\Error\SyntaxError;
/**
* @author Fabien Potencier <[email protected]>
*/
class Lexer
{
private $tokens;
private $code;
private $cursor;
private $lineno;
private $end;
private $state;
private $states;
private $brackets;
private $env;
private $source;
private $options;
private $regexes;
private $position;
private $positions;
private $currentVarBlockLine;
public const STATE_DATA = 0;
public const STATE_BLOCK = 1;
public const STATE_VAR = 2;
public const STATE_STRING = 3;
public const STATE_INTERPOLATION = 4;
public const REGEX_NAME = '/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A';
public const REGEX_NUMBER = '/[0-9]+(?:\.[0-9]+)?([Ee][\+\-][0-9]+)?/A';
public const REGEX_STRING = '/"([^#"\\\\]*(?:\\\\.[^#"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\'/As';
public const REGEX_DQ_STRING_DELIM = '/"/A';
public const REGEX_DQ_STRING_PART = '/[^#"\\\\]*(?:(?:\\\\.|#(?!\{))[^#"\\\\]*)*/As';
public const PUNCTUATION = '()[]{}?:.,|';
public function __construct(Environment $env, array $options = [])
{
$this->env = $env;
$this->options = array_merge([
'tag_comment' => ['{#', '#}'],
'tag_block' => ['{%', '%}'],
'tag_variable' => ['{{', '}}'],
'whitespace_trim' => '-',
'whitespace_line_trim' => '~',
'whitespace_line_chars' => ' \t\0\x0B',
'interpolation' => ['#{', '}'],
], $options);
// 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
$this->regexes = [
// }}
'lex_var' => '{
\s*
(?:'.
preg_quote($this->options['whitespace_trim'].$this->options['tag_variable'][1], '#').'\s*'. // -}}\s*
'|'.
preg_quote($this->options['whitespace_line_trim'].$this->options['tag_variable'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~}}[ \t\0\x0B]*
'|'.
preg_quote($this->options['tag_variable'][1], '#'). // }}
')
}Ax',
// %}
'lex_block' => '{
\s*
(?:'.
preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '#').'\s*\n?'. // -%}\s*\n?
'|'.
preg_quote($this->options['whitespace_line_trim'].$this->options['tag_block'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~%}[ \t\0\x0B]*
'|'.
preg_quote($this->options['tag_block'][1], '#').'\n?'. // %}\n?
')
}Ax',
// {% endverbatim %}
'lex_raw_data' => '{'.
preg_quote($this->options['tag_block'][0], '#'). // {%
'('.
$this->options['whitespace_trim']. // -
'|'.
$this->options['whitespace_line_trim']. // ~
')?\s*endverbatim\s*'.
'(?:'.
preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '#').'\s*'. // -%}
'|'.
preg_quote($this->options['whitespace_line_trim'].$this->options['tag_block'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~%}[ \t\0\x0B]*
'|'.
preg_quote($this->options['tag_block'][1], '#'). // %}
')
}sx',
'operator' => $this->getOperatorRegex(),
// #}
'lex_comment' => '{
(?:'.
preg_quote($this->options['whitespace_trim'].$this->options['tag_comment'][1], '#').'\s*\n?'. // -#}\s*\n?
'|'.
preg_quote($this->options['whitespace_line_trim'].$this->options['tag_comment'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~#}[ \t\0\x0B]*
'|'.
preg_quote($this->options['tag_comment'][1], '#').'\n?'. // #}\n?
')
}sx',
// verbatim %}
'lex_block_raw' => '{
\s*verbatim\s*
(?:'.
preg_quote($this->options['whitespace_trim'].$this->options['tag_block'][1], '#').'\s*'. // -%}\s*
'|'.
preg_quote($this->options['whitespace_line_trim'].$this->options['tag_block'][1], '#').'['.$this->options['whitespace_line_chars'].']*'. // ~%}[ \t\0\x0B]*
'|'.
preg_quote($this->options['tag_block'][1], '#'). // %}
')
}Asx',
'lex_block_line' => '{\s*line\s+(\d+)\s*'.preg_quote($this->options['tag_block'][1], '#').'}As',
// {{ or {% or {#
'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'], '#'). // -
'|'.
preg_quote($this->options['whitespace_line_trim'], '#'). // ~
')?
}sx',
'interpolation_start' => '{'.preg_quote($this->options['interpolation'][0], '#').'\s*}A',
'interpolation_end' => '{\s*'.preg_quote($this->options['interpolation'][1], '#').'}A',
];
}
public function tokenize(Source $source): TokenStream
{
$this->source = $source;
$this->code = str_replace(["\r\n", "\r"], "\n", $source->getCode());
$this->cursor = 0;
$this->lineno = 1;
$this->end = \strlen($this->code);
$this->tokens = [];
$this->state = self::STATE_DATA;
$this->states = [];
$this->brackets = [];
$this->position = -1;
// find all token starts in one go
preg_match_all($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;
}
}
$this->pushToken(/* Token::EOF_TYPE */ -1);
if (!empty($this->brackets)) {
list($expect, $lineno) = array_pop($this->brackets);
throw new SyntaxError(sprintf('Unclosed "%s".', $expect), $lineno, $this->source);
}
return new TokenStream($this->tokens, $this->source);
}
private function lexData(): void
{
// if no matches are left we return the rest of the template as simple text token
if ($this->position == \count($this->positions[0]) - 1) {
$this->pushToken(/* Token::TEXT_TYPE */ 0, substr($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] - $this->cursor);
// trim?
if (isset($this->positions[2][$this->position][0])) {
if ($this->options['whitespace_trim'] === $this->positions[2][$this->position][0]) {
// whitespace_trim detected ({%-, {{- or {#-)
$text = rtrim($text);
} elseif ($this->options['whitespace_line_trim'] === $this->positions[2][$this->position][0]) {
// whitespace_line_trim detected ({%~, {{~ or {#~)
// don't trim \r and \n
$text = rtrim($text, " \t\0\x0B");
}
}
$this->pushToken(/* Token::TEXT_TYPE */ 0, $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, 0, $this->cursor)) {
$this->moveCursor($match[0]);
$this->lexRawData();
// {% line \d+ %}
} elseif (preg_match($this->regexes['lex_block_line'], $this->code, $match, 0, $this->cursor)) {
$this->moveCursor($match[0]);
$this->lineno = (int) $match[1];
} else {
$this->pushToken(/* Token::BLOCK_START_TYPE */ 1);
$this->pushState(self::STATE_BLOCK);
$this->currentVarBlockLine = $this->lineno;
}
break;
case $this->options['tag_variable'][0]:
$this->pushToken(/* Token::VAR_START_TYPE */ 2);
$this->pushState(self::STATE_VAR);
$this->currentVarBlockLine = $this->lineno;
break;
}
}
private function lexBlock(): void
{
if (empty($this->brackets) && preg_match($this->regexes['lex_block'], $this->code, $match, 0, $this->cursor)) {
$this->pushToken(/* Token::BLOCK_END_TYPE */ 3);
$this->moveCursor($match[0]);
$this->popState();
} else {
$this->lexExpression();
}
}
private function lexVar(): void
{
if (empty($this->brackets) && preg_match($this->regexes['lex_var'], $this->code, $match, 0, $this->cursor)) {
$this->pushToken(/* Token::VAR_END_TYPE */ 4);
$this->moveCursor($match[0]);
$this->popState();
} else {
$this->lexExpression();
}
}
private function lexExpression(): void
{
// whitespace
if (preg_match('/\s+/A', $this->code, $match, 0, $this->cursor)) {
$this->moveCursor($match[0]);
if ($this->cursor >= $this->end) {
throw new SyntaxError(sprintf('Unclosed "%s".', self::STATE_BLOCK === $this->state ? 'block' : 'variable'), $this->currentVarBlockLine, $this->source);
}
}
// arrow function
if ('=' === $this->code[$this->cursor] && '>' === $this->code[$this->cursor + 1]) {
$this->pushToken(Token::ARROW_TYPE, '=>');
$this->moveCursor('=>');
}
// operators
elseif (preg_match($this->regexes['operator'], $this->code, $match, 0, $this->cursor)) {
$this->pushToken(/* Token::OPERATOR_TYPE */ 8, preg_replace('/\s+/', ' ', $match[0]));
$this->moveCursor($match[0]);
}
// names
elseif (preg_match(self::REGEX_NAME, $this->code, $match, 0, $this->cursor)) {
$this->pushToken(/* Token::NAME_TYPE */ 5, $match[0]);
$this->moveCursor($match[0]);
}
// numbers
elseif (preg_match(self::REGEX_NUMBER, $this->code, $match, 0, $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(/* Token::NUMBER_TYPE */ 6, $number);
$this->moveCursor($match[0]);
}
// punctuation
elseif (false !== strpos(self::PUNCTUATION, $this->code[$this->cursor])) {
// opening bracket
if (false !== strpos('([{', $this->code[$this->cursor])) {
$this->brackets[] = [$this->code[$this->cursor], $this->lineno];
}
// closing bracket
elseif (false !== strpos(')]}', $this->code[$this->cursor])) {
if (empty($this->brackets)) {
throw new SyntaxError(sprintf('Unexpected "%s".', $this->code[$this->cursor]), $this->lineno, $this->source);
}
list($expect, $lineno) = array_pop($this->brackets);
if ($this->code[$this->cursor] != strtr($expect, '([{', ')]}')) {
throw new SyntaxError(sprintf('Unclosed "%s".', $expect), $lineno, $this->source);
}
}
$this->pushToken(/* Token::PUNCTUATION_TYPE */ 9, $this->code[$this->cursor]);
++$this->cursor;
}
// strings
elseif (preg_match(self::REGEX_STRING, $this->code, $match, 0, $this->cursor)) {
$this->pushToken(/* Token::STRING_TYPE */ 7, stripcslashes(substr($match[0], 1, -1)));
$this->moveCursor($match[0]);
}
// opening double quoted string
elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, 0, $this->cursor)) {
$this->brackets[] = ['"', $this->lineno];
$this->pushState(self::STATE_STRING);
$this->moveCursor($match[0]);
}
// unlexable
else {
throw new SyntaxError(sprintf('Unexpected character "%s".', $this->code[$this->cursor]), $this->lineno, $this->source);
}
}
private function lexRawData(): void
{
if (!preg_match($this->regexes['lex_raw_data'], $this->code, $match, \PREG_OFFSET_CAPTURE, $this->cursor)) {
throw new SyntaxError('Unexpected end of file: Unclosed "verbatim" block.', $this->lineno, $this->source);
}
$text = substr($this->code, $this->cursor, $match[0][1] - $this->cursor);
$this->moveCursor($text.$match[0][0]);
// trim?
if (isset($match[1][0])) {
if ($this->options['whitespace_trim'] === $match[1][0]) {
// whitespace_trim detected ({%-, {{- or {#-)
$text = rtrim($text);
} else {
// whitespace_line_trim detected ({%~, {{~ or {#~)
// don't trim \r and \n
$text = rtrim($text, " \t\0\x0B");
}
}
$this->pushToken(/* Token::TEXT_TYPE */ 0, $text);
}
private function lexComment(): void
{
if (!preg_match($this->regexes['lex_comment'], $this->code, $match, \PREG_OFFSET_CAPTURE, $this->cursor)) {
throw new SyntaxError('Unclosed comment.', $this->lineno, $this->source);
}
$this->moveCursor(substr($this->code, $this->cursor, $match[0][1] - $this->cursor).$match[0][0]);
}
private function lexString(): void
{
if (preg_match($this->regexes['interpolation_start'], $this->code, $match, 0, $this->cursor)) {
$this->brackets[] = [$this->options['interpolation'][0], $this->lineno];
$this->pushToken(/* Token::INTERPOLATION_START_TYPE */ 10);
$this->moveCursor($match[0]);
$this->pushState(self::STATE_INTERPOLATION);
} elseif (preg_match(self::REGEX_DQ_STRING_PART, $this->code, $match, 0, $this->cursor) && \strlen($match[0]) > 0) {
$this->pushToken(/* Token::STRING_TYPE */ 7, stripcslashes($match[0]));
$this->moveCursor($match[0]);
} elseif (preg_match(self::REGEX_DQ_STRING_DELIM, $this->code, $match, 0, $this->cursor)) {
list($expect, $lineno) = array_pop($this->brackets);
if ('"' != $this->code[$this->cursor]) {
throw new SyntaxError(sprintf('Unclosed "%s".', $expect), $lineno, $this->source);
}
$this->popState();
++$this->cursor;
} else {
// unlexable
throw new SyntaxError(sprintf('Unexpected character "%s".', $this->code[$this->cursor]), $this->lineno, $this->source);
}
}
private function lexInterpolation(): void
{
$bracket = end($this->brackets);
if ($this->options['interpolation'][0] === $bracket[0] && preg_match($this->regexes['interpolation_end'], $this->code, $match, 0, $this->cursor)) {
array_pop($this->brackets);
$this->pushToken(/* Token::INTERPOLATION_END_TYPE */ 11);
$this->moveCursor($match[0]);
$this->popState();
} else {
$this->lexExpression();
}
}
private function pushToken($type, $value = ''): void
{
// do not push empty text tokens
if (/* Token::TEXT_TYPE */ 0 === $type && '' === $value) {
return;
}
$this->tokens[] = new Token($type, $value, $this->lineno);
}
private function moveCursor($text): void
{
$this->cursor += \strlen($text);
$this->lineno += substr_count($text, "\n");
}
private function getOperatorRegex(): string
{
$operators = array_merge(
['='],
array_keys($this->env->getUnaryOperators()),
array_keys($this->env->getBinaryOperators())
);
$operators = array_combine($operators, array_map('strlen', $operators));
arsort($operators);
$regex = [];
foreach ($operators as $operator => $length) {
// an operator that ends with a character must be followed by
// a whitespace, a parenthesis, an opening map [ or sequence {
$r = preg_quote($operator, '/');
if (ctype_alpha($operator[$length - 1])) {
$r .= '(?=[\s()\[{])';
}
// an operator that begins with a character must not have a dot or pipe before
if (ctype_alpha($operator[0])) {
$r = '(?<![\.\|])'.$r;
}
// an operator with a space can be any amount of whitespaces
$r = preg_replace('/\s+/', '\s+', $r);
$regex[] = $r;
}
return '/'.implode('|', $regex).'/A';
}
private function pushState($state): void
{
$this->states[] = $this->state;
$this->state = $state;
}
private function popState(): void
{
if (0 === \count($this->states)) {
throw new \LogicException('Cannot pop state without a previous state.');
}
$this->state = array_pop($this->states);
}
}
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