WordPress/wp-includes/pomo/plural-forms.php

352 lines
7.5 KiB
PHP
Raw Normal View History

<?php
/**
* A gettext Plural-Forms parser.
*
* @since 4.9.0
*/
if ( ! class_exists( 'Plural_Forms', false ) ) :
Code Modernization: Add `AllowDynamicProperties` attribute to all (parent) classes. Dynamic (non-explicitly declared) properties are deprecated as of PHP 8.2 and are expected to become a fatal error in PHP 9.0. There are a number of ways to mitigate this: * If it is an accidental typo for a declared property: fix the typo. * For known properties: declare them on the class. * For unknown properties: add the magic `__get()`, `__set()`, et al. methods to the class or let the class extend `stdClass` which has highly optimized versions of these magic methods built in. * For unknown ''use'' of dynamic properties, the `#[AllowDynamicProperties]` attribute can be added to the class. The attribute will automatically be inherited by child classes. Trac ticket #56034 is open to investigate and handle the third and fourth type of situations, however it has become clear this will need more time and will not be ready in time for WP 6.1. To reduce “noise” in the meantime, both in the error logs of WP users moving onto PHP 8.2, in the test run logs of WP itself, in test runs of plugins and themes, as well as to prevent duplicate tickets from being opened for the same issue, this commit adds the `#[AllowDynamicProperties]` attribute to all “parent” classes in WP. The logic used for this commit is as follows: * If a class already has the attribute: no action needed. * If a class does not `extend`: add the attribute. * If a class does `extend`: - If it extends `stdClass`: no action needed (as `stdClass` supports dynamic properties). - If it extends a PHP native class: add the attribute. - If it extends a class from one of WP's external dependencies: add the attribute. * In all other cases: no action — the attribute should not be needed as child classes inherit from the parent. Whether or not a class contains magic methods has not been taken into account, as a review of the currently existing magic methods has shown that those are generally not sturdy enough and often even set dynamic properties (which they should not). See the [https://www.youtube.com/watch?v=vDZWepDQQVE live stream from August 16, 2022] for more details. This commit only affects classes in the `src` directory of WordPress core. * Tests should not get this attribute, but should be fixed to not use dynamic properties instead. Patches for this are already being committed under ticket #56033. * While a number bundled themes (2014, 2019, 2020, 2021) contain classes, they are not a part of this commit and may be updated separately. Reference: [https://wiki.php.net/rfc/deprecate_dynamic_properties PHP RFC: Deprecate dynamic properties]. Follow-up to [53922]. Props jrf, hellofromTonya, markjaquith, peterwilsoncc, costdev, knutsp, aristath. See #56513, #56034. Built from https://develop.svn.wordpress.org/trunk@54133 git-svn-id: http://core.svn.wordpress.org/trunk@53692 1a063a9b-81f0-0310-95a4-ce76da25c4cd
2022-09-12 11:47:14 -04:00
#[AllowDynamicProperties]
class Plural_Forms {
/**
* Operator characters.
*
* @since 4.9.0
* @var string OP_CHARS Operator characters.
*/
const OP_CHARS = '|&><!=%?:';
/**
* Valid number characters.
*
* @since 4.9.0
* @var string NUM_CHARS Valid number characters.
*/
const NUM_CHARS = '0123456789';
/**
* Operator precedence.
*
* Operator precedence from highest to lowest. Higher numbers indicate
* higher precedence, and are executed first.
*
* @see https://en.wikipedia.org/wiki/Operators_in_C_and_C%2B%2B#Operator_precedence
*
* @since 4.9.0
* @var array $op_precedence Operator precedence from highest to lowest.
*/
protected static $op_precedence = array(
'%' => 6,
'<' => 5,
'<=' => 5,
'>' => 5,
'>=' => 5,
'==' => 4,
'!=' => 4,
'&&' => 3,
'||' => 2,
'?:' => 1,
'?' => 1,
'(' => 0,
')' => 0,
);
/**
* Tokens generated from the string.
*
* @since 4.9.0
* @var array $tokens List of tokens.
*/
protected $tokens = array();
/**
* Cache for repeated calls to the function.
*
* @since 4.9.0
* @var array $cache Map of $n => $result
*/
protected $cache = array();
/**
* Constructor.
*
* @since 4.9.0
*
* @param string $str Plural function (just the bit after `plural=` from Plural-Forms)
*/
public function __construct( $str ) {
$this->parse( $str );
}
/**
* Parse a Plural-Forms string into tokens.
*
* Uses the shunting-yard algorithm to convert the string to Reverse Polish
* Notation tokens.
*
* @since 4.9.0
*
* @throws Exception If there is a syntax or parsing error with the string.
*
* @param string $str String to parse.
*/
protected function parse( $str ) {
$pos = 0;
$len = strlen( $str );
// Convert infix operators to postfix using the shunting-yard algorithm.
$output = array();
$stack = array();
while ( $pos < $len ) {
$next = substr( $str, $pos, 1 );
switch ( $next ) {
// Ignore whitespace.
case ' ':
case "\t":
$pos++;
break;
// Variable (n).
case 'n':
$output[] = array( 'var' );
$pos++;
break;
// Parentheses.
case '(':
$stack[] = $next;
$pos++;
break;
case ')':
$found = false;
while ( ! empty( $stack ) ) {
$o2 = $stack[ count( $stack ) - 1 ];
if ( '(' !== $o2 ) {
$output[] = array( 'op', array_pop( $stack ) );
continue;
}
// Discard open paren.
array_pop( $stack );
$found = true;
break;
}
if ( ! $found ) {
throw new Exception( 'Mismatched parentheses' );
}
$pos++;
break;
// Operators.
case '|':
case '&':
case '>':
case '<':
case '!':
case '=':
case '%':
case '?':
$end_operator = strspn( $str, self::OP_CHARS, $pos );
$operator = substr( $str, $pos, $end_operator );
if ( ! array_key_exists( $operator, self::$op_precedence ) ) {
throw new Exception( sprintf( 'Unknown operator "%s"', $operator ) );
}
while ( ! empty( $stack ) ) {
$o2 = $stack[ count( $stack ) - 1 ];
// Ternary is right-associative in C.
if ( '?:' === $operator || '?' === $operator ) {
if ( self::$op_precedence[ $operator ] >= self::$op_precedence[ $o2 ] ) {
break;
}
} elseif ( self::$op_precedence[ $operator ] > self::$op_precedence[ $o2 ] ) {
break;
}
$output[] = array( 'op', array_pop( $stack ) );
}
$stack[] = $operator;
$pos += $end_operator;
break;
// Ternary "else".
case ':':
$found = false;
$s_pos = count( $stack ) - 1;
while ( $s_pos >= 0 ) {
$o2 = $stack[ $s_pos ];
if ( '?' !== $o2 ) {
$output[] = array( 'op', array_pop( $stack ) );
$s_pos--;
continue;
}
// Replace.
$stack[ $s_pos ] = '?:';
$found = true;
break;
}
if ( ! $found ) {
throw new Exception( 'Missing starting "?" ternary operator' );
}
$pos++;
break;
// Default - number or invalid.
default:
if ( $next >= '0' && $next <= '9' ) {
$span = strspn( $str, self::NUM_CHARS, $pos );
$output[] = array( 'value', intval( substr( $str, $pos, $span ) ) );
$pos += $span;
break;
}
throw new Exception( sprintf( 'Unknown symbol "%s"', $next ) );
}
}
while ( ! empty( $stack ) ) {
$o2 = array_pop( $stack );
if ( '(' === $o2 || ')' === $o2 ) {
throw new Exception( 'Mismatched parentheses' );
}
$output[] = array( 'op', $o2 );
}
$this->tokens = $output;
}
/**
* Get the plural form for a number.
*
* Caches the value for repeated calls.
*
* @since 4.9.0
*
* @param int $num Number to get plural form for.
* @return int Plural form value.
*/
public function get( $num ) {
if ( isset( $this->cache[ $num ] ) ) {
return $this->cache[ $num ];
}
$this->cache[ $num ] = $this->execute( $num );
return $this->cache[ $num ];
}
/**
* Execute the plural form function.
*
* @since 4.9.0
*
* @throws Exception If the plural form value cannot be calculated.
*
* @param int $n Variable "n" to substitute.
* @return int Plural form value.
*/
public function execute( $n ) {
$stack = array();
$i = 0;
$total = count( $this->tokens );
while ( $i < $total ) {
$next = $this->tokens[ $i ];
$i++;
if ( 'var' === $next[0] ) {
$stack[] = $n;
continue;
} elseif ( 'value' === $next[0] ) {
$stack[] = $next[1];
continue;
}
// Only operators left.
switch ( $next[1] ) {
case '%':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 % $v2;
break;
case '||':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 || $v2;
break;
case '&&':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 && $v2;
break;
case '<':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 < $v2;
break;
case '<=':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 <= $v2;
break;
case '>':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 > $v2;
break;
case '>=':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 >= $v2;
break;
case '!=':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 != $v2;
break;
case '==':
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 == $v2;
break;
case '?:':
$v3 = array_pop( $stack );
$v2 = array_pop( $stack );
$v1 = array_pop( $stack );
$stack[] = $v1 ? $v2 : $v3;
break;
default:
throw new Exception( sprintf( 'Unknown operator "%s"', $next[1] ) );
}
}
if ( count( $stack ) !== 1 ) {
throw new Exception( 'Too many values remaining on the stack' );
}
return (int) $stack[0];
}
}
endif;