<?php
+
/**
* Parse and evaluate a plural rule.
*
- * http://unicode.org/reports/tr35/#Language_Plural_Rules
+ * UTS #35 Revision 33
+ * http://www.unicode.org/reports/tr35/tr35-33/tr35-numbers.html#Language_Plural_Rules
*
- * @author Niklas Laxstrom, Tim Starling
+ * @author Niklas Laxström, Tim Starling
*
* @copyright Copyright © 2010-2012, Niklas Laxström
* @license http://www.gnu.org/copyleft/gpl.html GNU General Public License 2.0
* Evaluate a number against a set of plural rules. If a rule passes,
* return the index of plural rule.
*
- * @param int The number to be evaluated against the rules
- * @param array The associative array of plural rules in pluralform => rule format.
+ * @param int $number The number to be evaluated against the rules
+ * @param array $rules The associative array of plural rules in pluralform => rule format.
* @return int The index of the plural form which passed the evaluation
*/
public static function evaluate( $number, array $rules ) {
$rules = self::compile( $rules );
+
return self::evaluateCompiled( $number, $rules );
}
foreach ( $rules as &$rule ) {
$rule = CLDRPluralRuleConverter::convert( $rule );
}
+
return $rules;
}
* Evaluate a compiled set of rules returned by compile(). Do not allow
* the user to edit the compiled form, or else PHP errors may result.
*
- * @param int The number to be evaluated against the rules
- * @param array The associative array of plural rules in pluralform => rule format.
+ * @param string $number The number to be evaluated against the rules, in English, or it
+ * may be a type convertible to string.
+ * @param array $rules The associative array of plural rules in pluralform => rule format.
* @return int The index of the plural form which passed the evaluation
*/
public static function evaluateCompiled( $number, array $rules ) {
+ // Calculate the values of the operand symbols
+ $number = strval( $number );
+ if ( !preg_match( '/^ -? ( ([0-9]+) (?: \. ([0-9]+) )? )$/x', $number, $m ) ) {
+ wfDebug( __METHOD__ . ": invalid number input, returning 'other'\n" );
+
+ return count( $rules );
+ }
+ if ( !isset( $m[3] ) ) {
+ $operandSymbols = array(
+ 'n' => intval( $m[1] ),
+ 'i' => intval( $m[1] ),
+ 'v' => 0,
+ 'w' => 0,
+ 'f' => 0,
+ 't' => 0
+ );
+ } else {
+ $absValStr = $m[1];
+ $intStr = $m[2];
+ $fracStr = $m[3];
+ $operandSymbols = array(
+ 'n' => floatval( $absValStr ),
+ 'i' => intval( $intStr ),
+ 'v' => strlen( $fracStr ),
+ 'w' => strlen( rtrim( $fracStr, '0' ) ),
+ 'f' => intval( $fracStr ),
+ 't' => intval( rtrim( $fracStr, '0' ) ),
+ );
+ }
+
// The compiled form is RPN, with tokens strictly delimited by
// spaces, so this is a simple RPN evaluator.
foreach ( $rules as $i => $rule ) {
$nine = ord( '9' );
foreach ( StringUtils::explode( ' ', $rule ) as $token ) {
$ord = ord( $token );
- if ( $token === 'n' ) {
- $stack[] = $number;
+ if ( isset( $operandSymbols[$token] ) ) {
+ $stack[] = $operandSymbols[$token];
} elseif ( $ord >= $zero && $ord <= $nine ) {
$stack[] = intval( $token );
} else {
return $i;
}
}
- // None of the provided rules match. The number belongs to caregory
- // 'other' which comes last.
+ // None of the provided rules match. The number belongs to category
+ // 'other', which comes last.
return count( $rules );
}
*/
private static function doOperation( $token, $left, $right ) {
if ( in_array( $token, array( 'in', 'not-in', 'within', 'not-within' ) ) ) {
- if ( !( $right instanceof CLDRPluralRuleEvaluator_Range ) ) {
- $right = new CLDRPluralRuleEvaluator_Range( $right );
+ if ( !( $right instanceof CLDRPluralRuleEvaluatorRange ) ) {
+ $right = new CLDRPluralRuleEvaluatorRange( $right );
}
}
switch ( $token ) {
if ( is_int( $left ) ) {
return (int)fmod( $left, $right );
}
+
return fmod( $left, $right );
case ',':
- if ( $left instanceof CLDRPluralRuleEvaluator_Range ) {
+ if ( $left instanceof CLDRPluralRuleEvaluatorRange ) {
$range = $left;
} else {
- $range = new CLDRPluralRuleEvaluator_Range( $left );
+ $range = new CLDRPluralRuleEvaluatorRange( $left );
}
$range->add( $right );
+
return $range;
case '..':
- return new CLDRPluralRuleEvaluator_Range( $left, $right );
+ return new CLDRPluralRuleEvaluatorRange( $left, $right );
default:
throw new CLDRPluralRuleError( "Invalid RPN token" );
}
}
}
-
-/**
- * Evaluator helper class representing a range list.
- */
-class CLDRPluralRuleEvaluator_Range {
- /**
- * The parts
- *
- * @var array
- */
- public $parts = array();
-
- /**
- * Initialize a new instance of CLDRPluralRuleEvaluator_Range
- *
- * @param int $start The start of the range
- * @param int|bool $end The end of the range, or false if the range is not bounded.
- */
- function __construct( $start, $end = false ) {
- if ( $end === false ) {
- $this->parts[] = $start;
- } else {
- $this->parts[] = array( $start, $end );
- }
- }
-
- /**
- * Determine if the given number is inside the range.
- *
- * @param int $number The number to check
- * @param bool $integerConstraint If true, also asserts the number is an integer; otherwise, number simply has to be inside the range.
- * @return bool True if the number is inside the range; otherwise, false.
- */
- function isNumberIn( $number, $integerConstraint = true ) {
- foreach ( $this->parts as $part ) {
- if ( is_array( $part ) ) {
- if ( ( !$integerConstraint || floor( $number ) === (float)$number )
- && $number >= $part[0] && $number <= $part[1]
- ) {
- return true;
- }
- } else {
- if ( $number == $part ) {
- return true;
- }
- }
- }
- return false;
- }
-
- /**
- * Readable alias for isNumberIn( $number, false ), and the implementation
- * of the "within" operator.
- *
- * @param int $number The number to check
- * @return bool True if the number is inside the range; otherwise, false.
- */
- function isNumberWithin( $number ) {
- return $this->isNumberIn( $number, false );
- }
-
- /**
- * Add another part to this range.
- *
- * @param mixed The part to add, either a range object itself or a single number.
- */
- function add( $other ) {
- if ( $other instanceof self ) {
- $this->parts = array_merge( $this->parts, $other->parts );
- } else {
- $this->parts[] = $other;
- }
- }
-
- /**
- * Returns the string representation of the rule evaluator range.
- * The purpose of this method is to help debugging.
- *
- * @return string The string representation of the rule evaluator range
- */
- function __toString() {
- $s = 'Range(';
- foreach ( $this->parts as $i => $part ) {
- if ( $i ) {
- $s .= ', ';
- }
- if ( is_array( $part ) ) {
- $s .= $part[0] . '..' . $part[1];
- } else {
- $s .= $part;
- }
- }
- $s .= ')';
- return $s;
- }
-
-}
-
-/**
- * Helper class for converting rules to reverse polish notation (RPN).
- */
-class CLDRPluralRuleConverter {
- /**
- * The rule
- *
- * @var string
- */
- public $rule;
-
- /**
- * The position
- *
- * @var int
- */
- public $pos;
-
- /**
- * The last position possible
- *
- * @var int
- */
- public $end;
-
- /**
- * The operators
- *
- * @var array
- */
- public $operators = array();
-
- /**
- * The operands
- *
- * @var array
- */
- public $operands = array();
-
- /**
- * Precedence levels. Note that there's no need to worry about associativity
- * for the level 4 operators, since they return boolean and don't accept
- * boolean inputs.
- */
- static $precedence = array(
- 'or' => 2,
- 'and' => 3,
- 'is' => 4,
- 'is-not' => 4,
- 'in' => 4,
- 'not-in' => 4,
- 'within' => 4,
- 'not-within' => 4,
- 'mod' => 5,
- ',' => 6,
- '..' => 7,
- );
-
- /**
- * A character list defining whitespace, for use in strspn() etc.
- */
- const WHITESPACE_CLASS = " \t\r\n";
-
- /**
- * Same for digits. Note that the grammar given in UTS #35 doesn't allow
- * negative numbers or decimals.
- */
- const NUMBER_CLASS = '0123456789';
-
- /**
- * An anchored regular expression which matches a word at the current offset.
- */
- const WORD_REGEX = '/[a-zA-Z]+/A';
-
- /**
- * Convert a rule to RPN. This is the only public entry point.
- *
- * @param $rule The rule to convert
- * @return string The RPN representation of the rule
- */
- public static function convert( $rule ) {
- $parser = new self( $rule );
- return $parser->doConvert();
- }
-
- /**
- * Private constructor.
- */
- protected function __construct( $rule ) {
- $this->rule = $rule;
- $this->pos = 0;
- $this->end = strlen( $rule );
- }
-
- /**
- * Do the operation.
- *
- * @return string The RPN representation of the rule (e.g. "5 3 mod n is")
- */
- protected function doConvert() {
- $expectOperator = true;
-
- // Iterate through all tokens, saving the operators and operands to a
- // stack per Dijkstra's shunting yard algorithm.
- while ( false !== ( $token = $this->nextToken() ) ) {
- // In this grammar, there are only binary operators, so every valid
- // rule string will alternate between operator and operand tokens.
- $expectOperator = !$expectOperator;
-
- if ( $token instanceof CLDRPluralRuleConverter_Expression ) {
- // Operand
- if ( $expectOperator ) {
- $token->error( 'unexpected operand' );
- }
- $this->operands[] = $token;
- continue;
- } else {
- // Operator
- if ( !$expectOperator ) {
- $token->error( 'unexpected operator' );
- }
- // Resolve higher precedence levels
- $lastOp = end( $this->operators );
- while ( $lastOp && self::$precedence[$token->name] <= self::$precedence[$lastOp->name] ) {
- $this->doOperation( $lastOp, $this->operands );
- array_pop( $this->operators );
- $lastOp = end( $this->operators );
- }
- $this->operators[] = $token;
- }
- }
-
- // Finish off the stack
- while ( $op = array_pop( $this->operators ) ) {
- $this->doOperation( $op, $this->operands );
- }
-
- // Make sure the result is sane. The first case is possible for an empty
- // string input, the second should be unreachable.
- if ( !count( $this->operands ) ) {
- $this->error( 'condition expected' );
- } elseif ( count( $this->operands ) > 1 ) {
- $this->error( 'missing operator or too many operands' );
- }
-
- $value = $this->operands[0];
- if ( $value->type !== 'boolean' ) {
- $this->error( 'the result must have a boolean type' );
- }
-
- return $this->operands[0]->rpn;
- }
-
- /**
- * Fetch the next token from the input string.
- *
- * @return CLDRPluralRuleConverter_Fragment The next token
- */
- protected function nextToken() {
- if ( $this->pos >= $this->end ) {
- return false;
- }
-
- // Whitespace
- $length = strspn( $this->rule, self::WHITESPACE_CLASS, $this->pos );
- $this->pos += $length;
-
- if ( $this->pos >= $this->end ) {
- return false;
- }
-
- // Number
- $length = strspn( $this->rule, self::NUMBER_CLASS, $this->pos );
- if ( $length !== 0 ) {
- $token = $this->newNumber( substr( $this->rule, $this->pos, $length ), $this->pos );
- $this->pos += $length;
- return $token;
- }
-
- // Comma
- if ( $this->rule[$this->pos] === ',' ) {
- $token = $this->newOperator( ',', $this->pos, 1 );
- $this->pos ++;
- return $token;
- }
-
- // Dot dot
- if ( substr( $this->rule, $this->pos, 2 ) === '..' ) {
- $token = $this->newOperator( '..', $this->pos, 2 );
- $this->pos += 2;
- return $token;
- }
-
- // Word
- if ( !preg_match( self::WORD_REGEX, $this->rule, $m, 0, $this->pos ) ) {
- $this->error( 'unexpected character "' . $this->rule[$this->pos] . '"' );
- }
- $word1 = strtolower( $m[0] );
- $word2 = '';
- $nextTokenPos = $this->pos + strlen( $word1 );
- if ( $word1 === 'not' || $word1 === 'is' ) {
- // Look ahead one word
- $nextTokenPos += strspn( $this->rule, self::WHITESPACE_CLASS, $nextTokenPos );
- if ( $nextTokenPos < $this->end
- && preg_match( self::WORD_REGEX, $this->rule, $m, 0, $nextTokenPos )
- ) {
- $word2 = strtolower( $m[0] );
- $nextTokenPos += strlen( $word2 );
- }
- }
-
- // Two-word operators like "is not" take precedence over single-word operators like "is"
- if ( $word2 !== '' ) {
- $bothWords = "{$word1}-{$word2}";
- if ( isset( self::$precedence[$bothWords] ) ) {
- $token = $this->newOperator( $bothWords, $this->pos, $nextTokenPos - $this->pos );
- $this->pos = $nextTokenPos;
- return $token;
- }
- }
-
- // Single-word operators
- if ( isset( self::$precedence[$word1] ) ) {
- $token = $this->newOperator( $word1, $this->pos, strlen( $word1 ) );
- $this->pos += strlen( $word1 );
- return $token;
- }
-
- // The special numerical keyword "n"
- if ( $word1 === 'n' ) {
- $token = $this->newNumber( 'n', $this->pos );
- $this->pos ++;
- return $token;
- }
-
- $this->error( 'unrecognised word' );
- }
-
- /**
- * For the binary operator $op, pop its operands off the stack and push
- * a fragment with rpn and type members describing the result of that
- * operation.
- */
- protected function doOperation( $op ) {
- if ( count( $this->operands ) < 2 ) {
- $op->error( 'missing operand' );
- }
- $right = array_pop( $this->operands );
- $left = array_pop( $this->operands );
- $result = $op->operate( $left, $right );
- $this->operands[] = $result;
- }
-
- /**
- * Create a numerical expression object
- *
- * @return CLDRPluralRuleConverter_Expression The numerical expression
- */
- protected function newNumber( $text, $pos ) {
- return new CLDRPluralRuleConverter_Expression( $this, 'number', $text, $pos, strlen( $text ) );
- }
-
- /**
- * Create a binary operator
- *
- * @return CLDRPluralRuleConverter_Operator The operator
- */
- protected function newOperator( $type, $pos, $length ) {
- return new CLDRPluralRuleConverter_Operator( $this, $type, $pos, $length );
- }
-
- /**
- * Throw an error
- */
- protected function error( $message ) {
- throw new CLDRPluralRuleError( $message );
- }
-}
-
-/**
- * Helper for CLDRPluralRuleConverter.
- * The base class for operators and expressions, describing a region of the input string.
- */
-class CLDRPluralRuleConverter_Fragment {
- public $parser, $pos, $length, $end;
-
- function __construct( $parser, $pos, $length ) {
- $this->parser = $parser;
- $this->pos = $pos;
- $this->length = $length;
- $this->end = $pos + $length;
- }
-
- public function error( $message ) {
- $text = $this->getText();
- throw new CLDRPluralRuleError( "$message at position " . ( $this->pos + 1 ) . ": \"$text\"" );
- }
-
- public function getText() {
- return substr( $this->parser->rule, $this->pos, $this->length );
- }
-}
-
-/**
- * Helper for CLDRPluralRuleConverter.
- * An expression object, representing a region of the input string (for error
- * messages), the RPN notation used to evaluate it, and the result type for
- * validation.
- */
-class CLDRPluralRuleConverter_Expression extends CLDRPluralRuleConverter_Fragment {
- public $type, $rpn;
-
- function __construct( $parser, $type, $rpn, $pos, $length ) {
- parent::__construct( $parser, $pos, $length );
- $this->type = $type;
- $this->rpn = $rpn;
- }
-
- public function isType( $type ) {
- if ( $type === 'range' && ( $this->type === 'range' || $this->type === 'number' ) ) {
- return true;
- }
- if ( $type === $this->type ) {
- return true;
- }
- return false;
- }
-}
-
-/**
- * Helper for CLDRPluralRuleConverter.
- * An operator object, representing a region of the input string (for error
- * messages), and the binary operator at that location.
- */
-class CLDRPluralRuleConverter_Operator extends CLDRPluralRuleConverter_Fragment {
- /**
- * The name
- *
- * @var string
- */
- public $name;
-
- /**
- * Each op type has three characters: left operand type, right operand type and result type
- *
- * b = boolean
- * n = number
- * r = range
- *
- * A number is a kind of range.
- *
- * @var array
- */
- static $opTypes = array(
- 'or' => 'bbb',
- 'and' => 'bbb',
- 'is' => 'nnb',
- 'is-not' => 'nnb',
- 'in' => 'nrb',
- 'not-in' => 'nrb',
- 'within' => 'nrb',
- 'not-within' => 'nrb',
- 'mod' => 'nnn',
- ',' => 'rrr',
- '..' => 'nnr',
- );
-
- /**
- * Map converting from the abbrevation to the full form.
- *
- * @var array
- */
- static $typeSpecMap = array(
- 'b' => 'boolean',
- 'n' => 'number',
- 'r' => 'range',
- );
-
- /**
- * Initialize a new instance of a CLDRPluralRuleConverter_Operator object
- *
- * @param CLDRPluralRuleConverter $parser The parser
- * @param string $name The operator name
- * @param int $pos The position
- * @param int $pos The length
- */
- function __construct( $parser, $name, $pos, $length ) {
- parent::__construct( $parser, $pos, $length );
- $this->name = $name;
- }
-
- /**
- * Compute the operation
- *
- * @param CLDRPluralRuleConverter_Expression $left The left part of the expression
- * @param CLDRPluralRuleConverter_Expression $right The right part of the expression
- * @return CLDRPluralRuleConverter_Expression The result of the operation
- */
- public function operate( $left, $right ) {
- $typeSpec = self::$opTypes[$this->name];
-
- $leftType = self::$typeSpecMap[$typeSpec[0]];
- $rightType = self::$typeSpecMap[$typeSpec[1]];
- $resultType = self::$typeSpecMap[$typeSpec[2]];
-
- $start = min( $this->pos, $left->pos, $right->pos );
- $end = max( $this->end, $left->end, $right->end );
- $length = $end - $start;
-
- $newExpr = new CLDRPluralRuleConverter_Expression( $this->parser, $resultType,
- "{$left->rpn} {$right->rpn} {$this->name}",
- $start, $length );
-
- if ( !$left->isType( $leftType ) ) {
- $newExpr->error( "invalid type for left operand: expected $leftType, got {$left->type}" );
- }
-
- if ( !$right->isType( $rightType ) ) {
- $newExpr->error( "invalid type for right operand: expected $rightType, got {$right->type}" );
- }
- return $newExpr;
- }
-}
-
-/**
- * The exception class for all the classes in this file. This will be thrown
- * back to the caller if there is any validation error.
- */
-class CLDRPluralRuleError extends MWException {
- function __construct( $message ) {
- parent::__construct( 'CLDR plural rule error: ' . $message );
- }
-}