Page MenuHomeWickedGov Phorge
Files F4091417

Quantifier.php
No OneTemporary
Actions

Size
5 KB
Referenced Files
None
Subscribers
None

Quantifier.php
View Options

<?php
/**
* @file
* @license https://opensource.org/licenses/Apache-2.0 Apache-2.0
*/
namespace Wikimedia\CSS\Grammar;
use Iterator;
use UnexpectedValueException;
use Wikimedia\CSS\Objects\ComponentValueList;
use Wikimedia\CSS\Objects\Token;
/**
* Matcher that matches a sub-Matcher a certain number of times
* ("?", "*", "+", "#", "{A,B}" multipliers)
* @see https://www.w3.org/TR/2019/CR-css-values-3-20190606/#component-multipliers
*/
class Quantifier extends Matcher {
/** @var Matcher */
protected $matcher;
/** @var int */
protected $min;
/** @var int */
protected $max;
/** @var bool Whether matches are comma-separated */
protected $commas;
/**
* @param Matcher $matcher
* @param int|float $min Minimum number of matches
* @param int|float $max Maximum number of matches
* @param bool $commas Whether matches are comma-separated
*/
public function __construct( Matcher $matcher, $min, $max, $commas ) {
$this->matcher = $matcher;
$this->min = $min;
$this->max = $max;
$this->commas = (bool)$commas;
}
/**
* Implements "?": 0 or 1 matches
* @see https://www.w3.org/TR/2019/CR-css-values-3-20190606/#mult-opt
* @param Matcher $matcher
* @return static
*/
public static function optional( Matcher $matcher ) {
return new static( $matcher, 0, 1, false );
}
/**
* Implements "*": 0 or more matches
* @see https://www.w3.org/TR/2019/CR-css-values-3-20190606/#mult-zero-plus
* @param Matcher $matcher
* @return static
*/
public static function star( Matcher $matcher ) {
return new static( $matcher, 0, INF, false );
}
/**
* Implements "+": 1 or more matches
* @see https://www.w3.org/TR/2019/CR-css-values-3-20190606/#mult-one-plus
* @param Matcher $matcher
* @return static
*/
public static function plus( Matcher $matcher ) {
return new static( $matcher, 1, INF, false );
}
/**
* Implements "{A,B}": Between A and B matches
* @see https://www.w3.org/TR/2019/CR-css-values-3-20190606/#mult-num-range
* @param Matcher $matcher
* @param int|float $min Minimum number of matches
* @param int|float $max Maximum number of matches
* @return static
*/
public static function count( Matcher $matcher, $min, $max ) {
return new static( $matcher, $min, $max, false );
}
/**
* Implements "#" and "#{A,B}": Between A and B matches, comma-separated
* @see https://www.w3.org/TR/2019/CR-css-values-3-20190606/#mult-comma
* @param Matcher $matcher
* @param int|float $min Minimum number of matches
* @param int|float $max Maximum number of matches
* @return static
*/
public static function hash( Matcher $matcher, $min = 1, $max = INF ) {
return new static( $matcher, $min, $max, true );
}
/** @inheritDoc */
protected function generateMatches( ComponentValueList $values, $start, array $options ) {
$used = [];
// Maintain a stack of matches for backtracking purposes.
$stack = [
[
new GrammarMatch( $values, $start, 0 ),
$this->matcher->generateMatches( $values, $start, $options )
]
];
do {
/** @var $lastMatch GrammarMatch */
/** @var $iter Iterator<GrammarMatch> */
[ $lastMatch, $iter ] = $stack[count( $stack ) - 1];
// If the top of the stack has no more matches, pop it, maybe
// yield the last matched position, and loop.
if ( !$iter->valid() ) {
array_pop( $stack );
$ct = count( $stack );
$pos = $lastMatch->getNext();
if ( $ct >= $this->min && $ct <= $this->max ) {
$newMatch = $this->makeMatch( $values, $start, $pos, $lastMatch, $stack );
$mid = $newMatch->getUniqueID();
if ( !isset( $used[$mid] ) ) {
$used[$mid] = 1;
yield $newMatch;
}
}
continue;
}
// Find the next match for the current top of the stack.
$match = $iter->current();
$iter->next();
// Quantifiers don't work well when the quantified thing can be empty.
if ( $match->getLength() === 0 ) {
throw new UnexpectedValueException( 'Empty match in quantifier!' );
}
$nextFrom = $match->getNext();
// There can only be more matches after this one if we haven't
// reached our maximum yet.
$canBeMore = count( $stack ) < $this->max;
// Commas are slightly tricky:
// 1. If there is a following comma, start the next Matcher after it.
// 2. If not, there can't be any more Matchers following.
// And in either case optional whitespace is always allowed.
if ( $this->commas ) {
$n = $nextFrom;
if ( isset( $values[$n] ) && $values[$n] instanceof Token &&
// @phan-suppress-next-line PhanNonClassMethodCall False positive
$values[$n]->type() === Token::T_WHITESPACE
) {
$n = $this->next( $values, $n, [ 'skip-whitespace' => true ] + $options );
}
if ( isset( $values[$n] ) && $values[$n] instanceof Token &&
// @phan-suppress-next-line PhanNonClassMethodCall False positive
$values[$n]->type() === Token::T_COMMA
) {
$nextFrom = $this->next( $values, $n, [ 'skip-whitespace' => true ] + $options );
} else {
$canBeMore = false;
}
}
// If there can be more matches, push another one onto the stack
// and try it. Otherwise, yield and continue with the current match.
if ( $canBeMore ) {
$stack[] = [ $match, $this->matcher->generateMatches( $values, $nextFrom, $options ) ];
} else {
$ct = count( $stack );
$pos = $match->getNext();
if ( $ct >= $this->min && $ct <= $this->max ) {
$newMatch = $this->makeMatch( $values, $start, $pos, $match, $stack );
$mid = $newMatch->getUniqueID();
if ( !isset( $used[$mid] ) ) {
$used[$mid] = 1;
yield $newMatch;
}
}
}
} while ( $stack );
}
}

File Metadata

Mime Type
text/x-php
Expires
Aug 18 2026, 11:42 (5 w, 1 d ago)
Storage Engine
local-disk
Storage Format
Raw Data
Storage Handle
85/e2/f227c7f833fb2e78671b65d4d9b3
Default Alt Text
Quantifier.php (5 KB)

Event Timeline