- gettext: merge patch from Sunil Mohan Adapa which rewrites plural parser to not use eval()
- fix typo in aforementioned patch which caused plurals to never load - update code again to newer PHP constructor syntax
This commit is contained in:
Andrew Dolgov
parent
4f5ae94b62
commit
3588d5186e
|
|
@ -69,10 +69,10 @@ function get_list_of_locales($locale) {
|
||||||
* sr_CS.UTF-8@latin, sr_CS@latin, sr@latin, sr_CS.UTF-8, sr_CS, sr.
|
* sr_CS.UTF-8@latin, sr_CS@latin, sr@latin, sr_CS.UTF-8, sr_CS, sr.
|
||||||
*/
|
*/
|
||||||
$locale_names = array();
|
$locale_names = array();
|
||||||
$lang = NULL;
|
$lang = null;
|
||||||
$country = NULL;
|
$country = null;
|
||||||
$charset = NULL;
|
$charset = null;
|
||||||
$modifier = NULL;
|
$modifier = null;
|
||||||
if ($locale) {
|
if ($locale) {
|
||||||
if (preg_match("/^(?P<lang>[a-z]{2,3})" // language code
|
if (preg_match("/^(?P<lang>[a-z]{2,3})" // language code
|
||||||
."(?:_(?P<country>[A-Z]{2}))?" // country code
|
."(?:_(?P<country>[A-Z]{2}))?" // country code
|
||||||
|
|
|
||||||
|
|
@ -21,6 +21,8 @@
|
||||||
|
|
||||||
*/
|
*/
|
||||||
|
|
||||||
|
require('plurals.php');
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Provides a simple gettext replacement that works independently from
|
* Provides a simple gettext replacement that works independently from
|
||||||
* the system's gettext abilities.
|
* the system's gettext abilities.
|
||||||
|
|
@ -39,16 +41,16 @@ class gettext_reader {
|
||||||
|
|
||||||
//private:
|
//private:
|
||||||
var $BYTEORDER = 0; // 0: low endian, 1: big endian
|
var $BYTEORDER = 0; // 0: low endian, 1: big endian
|
||||||
var $STREAM = NULL;
|
var $STREAM = null;
|
||||||
var $short_circuit = false;
|
var $short_circuit = false;
|
||||||
var $enable_cache = false;
|
var $enable_cache = false;
|
||||||
var $originals = NULL; // offset of original table
|
var $originals = null; // offset of original table
|
||||||
var $translations = NULL; // offset of translation table
|
var $translations = null; // offset of translation table
|
||||||
var $pluralheader = NULL; // cache header field for plural forms
|
var $pluralheader = null; // cache header field for plural forms
|
||||||
var $total = 0; // total string count
|
var $total = 0; // total string count
|
||||||
var $table_originals = NULL; // table for original strings (offsets)
|
var $table_originals = null; // table for original strings (offsets)
|
||||||
var $table_translations = NULL; // table for translated strings (offsets)
|
var $table_translations = null; // table for translated strings (offsets)
|
||||||
var $cache_translations = NULL; // original -> translation mapping
|
var $cache_translations = null; // original -> translation mapping
|
||||||
|
|
||||||
|
|
||||||
/* Methods */
|
/* Methods */
|
||||||
|
|
@ -269,41 +271,6 @@ class gettext_reader {
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
|
||||||
* Sanitize plural form expression for use in PHP eval call.
|
|
||||||
*
|
|
||||||
* @access private
|
|
||||||
* @return string sanitized plural form expression
|
|
||||||
*/
|
|
||||||
function sanitize_plural_expression($expr) {
|
|
||||||
// Get rid of disallowed characters.
|
|
||||||
$expr = preg_replace('@[^a-zA-Z0-9_:;\(\)\?\|\&=!<>+*/\%-]@', '', $expr);
|
|
||||||
|
|
||||||
// Add parenthesis for tertiary '?' operator.
|
|
||||||
$expr .= ';';
|
|
||||||
$res = '';
|
|
||||||
$p = 0;
|
|
||||||
for ($i = 0; $i < strlen($expr); $i++) {
|
|
||||||
$ch = $expr[$i];
|
|
||||||
switch ($ch) {
|
|
||||||
case '?':
|
|
||||||
$res .= ' ? (';
|
|
||||||
$p++;
|
|
||||||
break;
|
|
||||||
case ':':
|
|
||||||
$res .= ') : (';
|
|
||||||
break;
|
|
||||||
case ';':
|
|
||||||
$res .= str_repeat( ')', $p) . ';';
|
|
||||||
$p = 0;
|
|
||||||
break;
|
|
||||||
default:
|
|
||||||
$res .= $ch;
|
|
||||||
}
|
|
||||||
}
|
|
||||||
return $res;
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Parse full PO header and extract only plural forms line.
|
* Parse full PO header and extract only plural forms line.
|
||||||
*
|
*
|
||||||
|
|
@ -327,17 +294,17 @@ class gettext_reader {
|
||||||
function get_plural_forms() {
|
function get_plural_forms() {
|
||||||
// lets assume message number 0 is header
|
// lets assume message number 0 is header
|
||||||
// this is true, right?
|
// this is true, right?
|
||||||
$this->load_tables();
|
$this->load_tables();
|
||||||
|
|
||||||
// cache header field for plural forms
|
// cache header field for plural forms
|
||||||
if (! is_string($this->pluralheader)) {
|
if ($this->pluralheader === null) {
|
||||||
if ($this->enable_cache) {
|
if ($this->enable_cache) {
|
||||||
$header = $this->cache_translations[""];
|
$header = $this->cache_translations[""];
|
||||||
} else {
|
} else {
|
||||||
$header = $this->get_translation_string(0);
|
$header = $this->get_translation_string(0);
|
||||||
}
|
}
|
||||||
$expr = $this->extract_plural_forms_header_from_po_header($header);
|
$expr = $this->extract_plural_forms_header_from_po_header($header);
|
||||||
$this->pluralheader = $this->sanitize_plural_expression($expr);
|
$this->pluralheader = new PluralHeader($expr);
|
||||||
}
|
}
|
||||||
return $this->pluralheader;
|
return $this->pluralheader;
|
||||||
}
|
}
|
||||||
|
|
@ -353,17 +320,14 @@ class gettext_reader {
|
||||||
if (!is_int($n)) {
|
if (!is_int($n)) {
|
||||||
throw new InvalidArgumentException(
|
throw new InvalidArgumentException(
|
||||||
"Select_string only accepts integers: " . $n);
|
"Select_string only accepts integers: " . $n);
|
||||||
}
|
}
|
||||||
$string = $this->get_plural_forms();
|
|
||||||
$string = str_replace('nplurals',"\$total",$string);
|
|
||||||
$string = str_replace("n",$n,$string);
|
|
||||||
$string = str_replace('plural',"\$plural",$string);
|
|
||||||
|
|
||||||
$total = 0;
|
$plural_header = $this->get_plural_forms();
|
||||||
$plural = 0;
|
$plural = $plural_header->expression->evaluate($n);
|
||||||
|
|
||||||
|
if ($plural < 0) $plural = 0;
|
||||||
|
if ($plural >= $plural_header->total) $plural = $plural_header->total - 1;
|
||||||
|
|
||||||
eval("$string");
|
|
||||||
if ($plural >= $total) $plural = $total - 1;
|
|
||||||
return $plural;
|
return $plural;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
@ -387,7 +351,7 @@ class gettext_reader {
|
||||||
// find out the appropriate form
|
// find out the appropriate form
|
||||||
$select = $this->select_string($number);
|
$select = $this->select_string($number);
|
||||||
|
|
||||||
// this should contains all strings separated by NULLs
|
// this should contains all strings separated by nulls
|
||||||
$key = $single . chr(0) . $plural;
|
$key = $single . chr(0) . $plural;
|
||||||
|
|
||||||
|
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,461 @@
|
||||||
|
<?php
|
||||||
|
/*
|
||||||
|
Copyright (c) 2020 Sunil Mohan Adapa <sunil at medhas dot org>
|
||||||
|
|
||||||
|
Drop in replacement for native gettext.
|
||||||
|
|
||||||
|
This file is part of PHP-gettext.
|
||||||
|
|
||||||
|
PHP-gettext is free software; you can redistribute it and/or modify
|
||||||
|
it under the terms of the GNU General Public License as published by
|
||||||
|
the Free Software Foundation; either version 2 of the License, or
|
||||||
|
(at your option) any later version.
|
||||||
|
|
||||||
|
PHP-gettext is distributed in the hope that it will be useful,
|
||||||
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||||
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||||
|
GNU General Public License for more details.
|
||||||
|
|
||||||
|
You should have received a copy of the GNU General Public License
|
||||||
|
along with PHP-gettext; if not, write to the Free Software
|
||||||
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||||
|
|
||||||
|
*/
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Lexical analyzer for gettext plurals expression. Takes a string to parse
|
||||||
|
* during construction and returns a single token every time peek() or
|
||||||
|
* fetch_token() are called. The special string '__END__' is returned if there
|
||||||
|
* are no more tokens to be read. Spaces are ignored during tokenization.
|
||||||
|
*/
|
||||||
|
class PluralsLexer {
|
||||||
|
private $string;
|
||||||
|
private $position;
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Constructor
|
||||||
|
*
|
||||||
|
* @param string string Contains the value gettext plurals expression to
|
||||||
|
* analyze.
|
||||||
|
*/
|
||||||
|
public function __construct(string $string) {
|
||||||
|
$this->string = $string;
|
||||||
|
$this->position = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Return the next token and the length to advance the read position without
|
||||||
|
* actually advancing the read position. Tokens for operators and variables
|
||||||
|
* are simple strings containing the operator or variable. If there are no
|
||||||
|
* more token to provide, the special value ['__END__', 0] is returned. If
|
||||||
|
* there was an unexpected input an Exception is raised.
|
||||||
|
*
|
||||||
|
* @access private
|
||||||
|
* @throws Exception If there is unexpected input in the provided string.
|
||||||
|
* @return array The next token and length to advance the current position.
|
||||||
|
*/
|
||||||
|
private function _tokenize() {
|
||||||
|
$buf = $this->string;
|
||||||
|
|
||||||
|
// Consume all spaces until the next token
|
||||||
|
$index = $this->position;
|
||||||
|
while ($index < strlen($buf) && $buf[$index] == ' ') {
|
||||||
|
$index++;
|
||||||
|
}
|
||||||
|
$this->position = $index;
|
||||||
|
|
||||||
|
// Return special token if next of the string is reached.
|
||||||
|
if (strlen($buf) - $index == 0) {
|
||||||
|
return ['__END__', 0];
|
||||||
|
}
|
||||||
|
|
||||||
|
// Operators with two characters
|
||||||
|
$doubles = ['==', '!=', '>=', '<=', '&&', '||'];
|
||||||
|
$next = substr($buf, $index, 2);
|
||||||
|
if (in_array($next, $doubles)) {
|
||||||
|
return [$next, 2];
|
||||||
|
}
|
||||||
|
|
||||||
|
// Operators with single character or variable 'n'.
|
||||||
|
$singles = [
|
||||||
|
'n', '(', ')', '?', ':', '+', '-', '*', '/', '%', '!', '>', '<'];
|
||||||
|
if (in_array($buf[$index], $singles)) {
|
||||||
|
return [$buf[$index], 1];
|
||||||
|
}
|
||||||
|
|
||||||
|
// Whole number constants, return an integer.
|
||||||
|
$digits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
|
||||||
|
$pos = $index;
|
||||||
|
while ($pos < strlen($buf) && in_array($buf[$pos], $digits)) {
|
||||||
|
$pos++;
|
||||||
|
}
|
||||||
|
if ($pos != $index) {
|
||||||
|
$length = $pos - $index;
|
||||||
|
return [(int)substr($buf, $index, $length), $length];
|
||||||
|
}
|
||||||
|
|
||||||
|
// Throw and exception for all other unexpected input in the string.
|
||||||
|
throw new Exception('Lexical analysis failed');
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Return the next token without actually advancing the read position.
|
||||||
|
* Tokens for operators and variables are simple strings containing the
|
||||||
|
* operator or variable. If there are no more tokens to provide, the special
|
||||||
|
* value '__END__' is returned. If there was an unexpected input an
|
||||||
|
* Exception is raised.
|
||||||
|
*
|
||||||
|
* @throws Exception If there is unexpected input in the provided string.
|
||||||
|
* @return string The next token.
|
||||||
|
*/
|
||||||
|
public function peek() {
|
||||||
|
list($token, $length) = $this->_tokenize();
|
||||||
|
return $token;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Return the next token after advancing the read position. Tokens for
|
||||||
|
* operators and variables are simple strings containing the operator or
|
||||||
|
* variable. If there are no more token to provide, the special value
|
||||||
|
* '__END__' is returned. If there was an unexpected input an Exception is
|
||||||
|
* raised.
|
||||||
|
*
|
||||||
|
* @throws Exception If there is unexpected input in the provided string.
|
||||||
|
* @return string The next token.
|
||||||
|
*/
|
||||||
|
public function fetch_token() {
|
||||||
|
list($token, $length) = $this->_tokenize();
|
||||||
|
$this->position += $length;
|
||||||
|
return $token;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* A parsed representation of the gettext plural expression. This is a tree
|
||||||
|
* containing further expressions depending on how nested the given input is.
|
||||||
|
* Calling the evaluate() function computes the value of the expression if the
|
||||||
|
* variable 'n' is set a certain value. This is used to decide which plural
|
||||||
|
* string translation to use based on the number items at hand.
|
||||||
|
*/
|
||||||
|
class PluralsExpression {
|
||||||
|
private $operator;
|
||||||
|
private $operands;
|
||||||
|
|
||||||
|
const BINARY_OPERATORS = [
|
||||||
|
'==', '!=', '>=', '<=', '&&', '||', '+', '-', '*', '/', '%', '>', '<'];
|
||||||
|
const UNARY_OPERATORS = ['!'];
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Constructor
|
||||||
|
*
|
||||||
|
* @param string Operator for the expression.
|
||||||
|
* @param (int|string|PuralsExpression)[] Variable number of operands of the
|
||||||
|
* expression. One int operand is expected in case the operator is 'const'.
|
||||||
|
* One string operand with value 'n' is expected in case the operator is
|
||||||
|
* 'var'. For all other operators, the operands much be objects of type
|
||||||
|
* PluralExpression. Unary operators expect one operand, binary operators
|
||||||
|
* expect two operands and trinary operators expect three operands.
|
||||||
|
*/
|
||||||
|
public function __construct($operator, ...$operands) {
|
||||||
|
$this->operator = $operator;
|
||||||
|
$this->operands = $operands;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Return a parenthesized string representation of the expression for
|
||||||
|
* debugging purposes.
|
||||||
|
*
|
||||||
|
* @return string A string representation of the expression.
|
||||||
|
*/
|
||||||
|
public function to_string() {
|
||||||
|
if ($this->operator == 'const' || $this->operator == 'var') {
|
||||||
|
return $this->operands[0];
|
||||||
|
} elseif (in_array($this->operator, self::BINARY_OPERATORS)) {
|
||||||
|
return sprintf(
|
||||||
|
"(%s %s %s)", $this->operands[0]->to_string(), $this->operator,
|
||||||
|
$this->operands[1]->to_string());
|
||||||
|
} elseif (in_array($this->operator, self::UNARY_OPERATORS)) {
|
||||||
|
return sprintf(
|
||||||
|
"(%s %s)", $this->operator, $this->operands[0]->to_string());
|
||||||
|
} elseif ($this->operator == '?') {
|
||||||
|
return sprintf(
|
||||||
|
"(%s ? %s : %s)", $this->operands[0]->to_string(),
|
||||||
|
$this->operands[1]->to_string(),
|
||||||
|
$this->operands[2]->to_string());
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Return the computed value of the expression if the variable 'n' is set to
|
||||||
|
* a certain value.
|
||||||
|
*
|
||||||
|
* @param int The value of the variable n to use when evaluating.
|
||||||
|
* @throws Exception If the expression has been constructed incorrectly.
|
||||||
|
* @return int The value of the expression after evaluation.
|
||||||
|
*/
|
||||||
|
public function evaluate($n) {
|
||||||
|
if (!in_array($this->operator, ['const', 'var'])) {
|
||||||
|
$operand1 = $this->operands[0]->evaluate($n);
|
||||||
|
}
|
||||||
|
if (in_array($this->operator, self::BINARY_OPERATORS) ||
|
||||||
|
$this->operator == '?') {
|
||||||
|
$operand2 = $this->operands[1]->evaluate($n);
|
||||||
|
}
|
||||||
|
if ($this->operator == '?') {
|
||||||
|
$operand3 = $this->operands[2]->evaluate($n);
|
||||||
|
}
|
||||||
|
|
||||||
|
switch ($this->operator) {
|
||||||
|
case 'const':
|
||||||
|
return $this->operands[0];
|
||||||
|
case 'var':
|
||||||
|
return $n;
|
||||||
|
case '!':
|
||||||
|
return !($operand1);
|
||||||
|
case '==':
|
||||||
|
return $operand1 == $operand2;
|
||||||
|
case '!=':
|
||||||
|
return $operand1 != $operand2;
|
||||||
|
case '>=':
|
||||||
|
return $operand1 >= $operand2;
|
||||||
|
case '<=':
|
||||||
|
return $operand1 <= $operand2;
|
||||||
|
case '>':
|
||||||
|
return $operand1 > $operand2;
|
||||||
|
case '<':
|
||||||
|
return $operand1 < $operand2;
|
||||||
|
case '&&':
|
||||||
|
return $operand1 && $operand2;
|
||||||
|
case '||':
|
||||||
|
return $operand1 || $operand2;
|
||||||
|
case '+':
|
||||||
|
return $operand1 + $operand2;
|
||||||
|
case '-':
|
||||||
|
return $operand1 - $operand2;
|
||||||
|
case '*':
|
||||||
|
return $operand1 * $operand2;
|
||||||
|
case '/':
|
||||||
|
return (int)($operand1 / $operand2);
|
||||||
|
case '%':
|
||||||
|
return $operand1 % $operand2;
|
||||||
|
case '?':
|
||||||
|
return $operand1 ? $operand2 : $operand3;
|
||||||
|
default:
|
||||||
|
throw new Exception('Invalid expression');
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* A simple operator-precedence parser for gettext plural expressions. Takes a
|
||||||
|
* string during construction and returns a PluralsExpression tree when
|
||||||
|
* parse() is called.
|
||||||
|
*/
|
||||||
|
class PluralsParser {
|
||||||
|
private $lexer;
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Operator precedence. The parsing only happens with minimum precedence of
|
||||||
|
* 0. However, ':' and ')' exist here to make sure that parsing does not
|
||||||
|
* proceed beyond them when they are not to be parsed.
|
||||||
|
*/
|
||||||
|
private const PREC = [
|
||||||
|
':' => -1, '?' => 0, '||' => 1, '&&' => 2, '==' => 3, '!=' => 3,
|
||||||
|
'>' => 4, '<' => 4, '>=' => 4, '<=' => 4, '+' => 5, '-' => 5, '*' => 6,
|
||||||
|
'/' => 6, '%' => 6, '!' => 7, '__END__' => -1, ')' => -1
|
||||||
|
];
|
||||||
|
|
||||||
|
// List of right associative operators
|
||||||
|
private const RIGHT_ASSOC = ['?'];
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Constructor
|
||||||
|
*
|
||||||
|
* @param string string the plural expression to be parsed.
|
||||||
|
*/
|
||||||
|
public function __construct(string $string) {
|
||||||
|
$this->lexer = new PluralsLexer($string);
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Expect a primary next for parsing and return a PluralsExpression or throw
|
||||||
|
* and exception otherwise. A primary can be the variable 'n', an whole
|
||||||
|
* number constant, a unary operator expression string with '!', or a
|
||||||
|
* parenthesis expression.
|
||||||
|
*
|
||||||
|
* @throws Exception If the next token is not a primary or if parenthesis
|
||||||
|
* expression is not closes properly with ')'.
|
||||||
|
* @return PluralsExpression That is constructed from the parsed primary.
|
||||||
|
*/
|
||||||
|
private function _parse_primary() {
|
||||||
|
$token = $this->lexer->fetch_token();
|
||||||
|
if ($token === 'n') {
|
||||||
|
return new PluralsExpression('var', 'n');
|
||||||
|
} elseif (is_int($token)) {
|
||||||
|
return new PluralsExpression('const', (int)$token);
|
||||||
|
} elseif ($token === '!') {
|
||||||
|
return new PluralsExpression('!', $this->_parse_primary());
|
||||||
|
} elseif ($token === '(') {
|
||||||
|
$result = $this->_parse($this->_parse_primary(), 0);
|
||||||
|
if ($this->lexer->fetch_token() != ')') {
|
||||||
|
throw new Exception('Mismatched parenthesis');
|
||||||
|
}
|
||||||
|
return $result;
|
||||||
|
}
|
||||||
|
|
||||||
|
throw new Exception('Primary expected');
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Fetch an operator from the lexical analyzer and test for it. Optionally
|
||||||
|
* advance the position of the lexical analyzer to next token. Raise
|
||||||
|
* exception if the token retrieved is not an operator.
|
||||||
|
*
|
||||||
|
* @access private
|
||||||
|
* @param bool peek A flag to indicate whether the position of the lexical
|
||||||
|
* analyzer should *not* be advanced. If false, the lexical analyzer is
|
||||||
|
* advanced by one token.
|
||||||
|
* @throws Exception If the token read is not an operator.
|
||||||
|
* @return string The operator that has been fetched from the lexical
|
||||||
|
* analyzer.
|
||||||
|
*/
|
||||||
|
private function _parse_operator($peek) {
|
||||||
|
if ($peek) {
|
||||||
|
$token = $this->lexer->peek();
|
||||||
|
} else {
|
||||||
|
$token = $this->lexer->fetch_token();
|
||||||
|
}
|
||||||
|
|
||||||
|
if ($token !== null && !array_key_exists($token, self::PREC)) {
|
||||||
|
throw new Exception('Operator expected');
|
||||||
|
}
|
||||||
|
return $token;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* A parsing method suitable for recursion.
|
||||||
|
*
|
||||||
|
* @access private
|
||||||
|
* @param ParserExpression left_side A pre-parsed left-hand side expression
|
||||||
|
* of the file expression to be constructed. This helps with recursion.
|
||||||
|
* @param int min_precedence The minimum value of precedence for the
|
||||||
|
* operators to be considered for parsing. Parsing will stop and current
|
||||||
|
* expression is returned if an operator of a lower precedence is
|
||||||
|
* encountered.
|
||||||
|
* @throws Exception If the input string does not conform to the grammar of
|
||||||
|
* the gettext plural expression.
|
||||||
|
* @return ParserExpression A complete expression after parsing.
|
||||||
|
*/
|
||||||
|
private function _parse($left_side, $min_precedence) {
|
||||||
|
$next_token = $this->_parse_operator(true);
|
||||||
|
|
||||||
|
while (self::PREC[$next_token] >= $min_precedence) {
|
||||||
|
$operator = $this->_parse_operator(false);
|
||||||
|
$right_side = $this->_parse_primary();
|
||||||
|
|
||||||
|
$next_token = $this->_parse_operator(true);
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Consume (recursively) into right hand side all expressions of higher
|
||||||
|
* precedence.
|
||||||
|
*/
|
||||||
|
while ((self::PREC[$operator] < self::PREC[$next_token]) ||
|
||||||
|
((self::PREC[$operator] == self::PREC[$next_token]) &&
|
||||||
|
in_array($operator, self::RIGHT_ASSOC))) {
|
||||||
|
$right_side = $this->_parse(
|
||||||
|
$right_side, self::PREC[$next_token]);
|
||||||
|
$next_token = $this->_parse_operator(true);
|
||||||
|
}
|
||||||
|
|
||||||
|
if ($operator != '?') {
|
||||||
|
/*
|
||||||
|
* Handling for all binary operators. Consume into left hand side all
|
||||||
|
* expressions of equal precedence.
|
||||||
|
*/
|
||||||
|
$left_side = new PluralsExpression($operator, $left_side, $right_side);
|
||||||
|
} else {
|
||||||
|
// Special handling for (a ? b : c) expression
|
||||||
|
$operator = $this->lexer->fetch_token();
|
||||||
|
if ($operator != ':') {
|
||||||
|
throw new Exception('Invalid ? expression');
|
||||||
|
}
|
||||||
|
|
||||||
|
$right_side2 = $this->_parse(
|
||||||
|
$this->_parse_primary(), self::PREC[$operator] + 1);
|
||||||
|
$next_token = $this->_parse_operator(true);
|
||||||
|
$left_side = new PluralsExpression(
|
||||||
|
'?', $left_side, $right_side, $right_side2);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
return $left_side;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* A simple implementation of an operator-precedence parser. See:
|
||||||
|
* https://en.wikipedia.org/wiki/Operator-precedence_parser for an analysis
|
||||||
|
* of the algorithm.
|
||||||
|
*
|
||||||
|
* @throws Exception If the input string does not conform to the grammar of
|
||||||
|
* the gettext plural expression.
|
||||||
|
* @return ParserExpression A complete expression after parsing.
|
||||||
|
*/
|
||||||
|
public function parse() {
|
||||||
|
$expression = $this->_parse($this->_parse_primary(), 0);
|
||||||
|
// Special handling for an extra ')' at the end.
|
||||||
|
if ($this->lexer->peek() != '__END__') {
|
||||||
|
throw new Exception('Could not parse completely');
|
||||||
|
}
|
||||||
|
return $expression;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Provides a class to parse the value of the 'Plural-Forms:' header in the
|
||||||
|
* gettext translation files. Holds the expression tree and the number of
|
||||||
|
* plurals after parsing. Parsing happens during construction which takes as
|
||||||
|
* its only argument the string to parse. Error during parsing are silently
|
||||||
|
* suppressed and the fallback behavior is used with the value for Germanic
|
||||||
|
* languages as follows: "nplurals=2; plural=n == 1 ? 0 : 1;".
|
||||||
|
*/
|
||||||
|
class PluralHeader {
|
||||||
|
public $total;
|
||||||
|
public $expression;
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Constructor
|
||||||
|
*
|
||||||
|
* @param string The value of the Plural-Forms: header as seen in .po files.
|
||||||
|
*/
|
||||||
|
function __construct($string) {
|
||||||
|
try {
|
||||||
|
list($total, $expression) = $this->parse($string);
|
||||||
|
} catch (Exception $e) {
|
||||||
|
$string = "nplurals=2; plural=n == 1 ? 0 : 1;";
|
||||||
|
list($total, $expression) = $this->parse($string);
|
||||||
|
}
|
||||||
|
$this->total = $total;
|
||||||
|
$this->expression = $expression;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Return the number of plural forms and the parsed expression tree.
|
||||||
|
*
|
||||||
|
* @access private
|
||||||
|
* @param string string The value of the Plural-Forms: header.
|
||||||
|
* @throws Exception If the string could not be parsed.
|
||||||
|
* @return array The number of plural forms and parsed expression tree.
|
||||||
|
*/
|
||||||
|
private function parse($string) {
|
||||||
|
$regex = "/^\s*nplurals\s*=\s*(\d+)\s*;\s*plural\s*=([^;]+);/i";
|
||||||
|
if (preg_match($regex, $string, $matches)) {
|
||||||
|
$total = (int)$matches[1];
|
||||||
|
$expression_string = $matches[2];
|
||||||
|
} else {
|
||||||
|
throw new Exception('Invalid header value');
|
||||||
|
}
|
||||||
|
|
||||||
|
$parser = new PluralsParser($expression_string);
|
||||||
|
$expression = $parser->parse();
|
||||||
|
return [$total, $expression];
|
||||||
|
}
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue