mediawiki-extensions-Parser.../Expr.php
Siebrand 31a8009442 Remove PHP4-isms in type casting
Change-Id: I0ec1ecec14623a79ad52e7ff9285849398f48d3c
2016-04-01 22:47:10 +00:00

679 lines
18 KiB
PHP
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?php
if ( !defined( 'MEDIAWIKI' ) ) {
die( 'This file is a MediaWiki extension, it is not a valid entry point' );
}
// Character classes
define( 'EXPR_WHITE_CLASS', " \t\r\n" );
define( 'EXPR_NUMBER_CLASS', '0123456789.' );
// Token types
define( 'EXPR_WHITE', 1 );
define( 'EXPR_NUMBER', 2 );
define( 'EXPR_NEGATIVE', 3 );
define( 'EXPR_POSITIVE', 4 );
define( 'EXPR_PLUS', 5 );
define( 'EXPR_MINUS', 6 );
define( 'EXPR_TIMES', 7 );
define( 'EXPR_DIVIDE', 8 );
define( 'EXPR_MOD', 9 );
define( 'EXPR_OPEN', 10 );
define( 'EXPR_CLOSE', 11 );
define( 'EXPR_AND', 12 );
define( 'EXPR_OR', 13 );
define( 'EXPR_NOT', 14 );
define( 'EXPR_EQUALITY', 15 );
define( 'EXPR_LESS', 16 );
define( 'EXPR_GREATER', 17 );
define( 'EXPR_LESSEQ', 18 );
define( 'EXPR_GREATEREQ', 19 );
define( 'EXPR_NOTEQ', 20 );
define( 'EXPR_ROUND', 21 );
define( 'EXPR_EXPONENT', 22 );
define( 'EXPR_SINE', 23 );
define( 'EXPR_COSINE', 24 );
define( 'EXPR_TANGENS', 25 );
define( 'EXPR_ARCSINE', 26 );
define( 'EXPR_ARCCOS', 27 );
define( 'EXPR_ARCTAN', 28 );
define( 'EXPR_EXP', 29 );
define( 'EXPR_LN', 30 );
define( 'EXPR_ABS', 31 );
define( 'EXPR_FLOOR', 32 );
define( 'EXPR_TRUNC', 33 );
define( 'EXPR_CEIL', 34 );
define( 'EXPR_POW', 35 );
define( 'EXPR_PI', 36 );
define( 'EXPR_FMOD', 37 );
define( 'EXPR_SQRT' , 38 );
class ExprError extends Exception {
/**
* @param $msg string
* @param $parameter string
*/
public function __construct( $msg, $parameter = '' ) {
// Give grep a chance to find the usages:
// pfunc_expr_stack_exhausted, pfunc_expr_unexpected_number, pfunc_expr_preg_match_failure,
// pfunc_expr_unrecognised_word, pfunc_expr_unexpected_operator, pfunc_expr_missing_operand,
// pfunc_expr_unexpected_closing_bracket, pfunc_expr_unrecognised_punctuation,
// pfunc_expr_unclosed_bracket, pfunc_expr_division_by_zero, pfunc_expr_invalid_argument,
// pfunc_expr_invalid_argument_ln, pfunc_expr_unknown_error, pfunc_expr_not_a_number
$this->message = wfMessage( "pfunc_expr_$msg", $parameter )->inContentLanguage()->text();
}
}
class ExprParser {
public $maxStackSize = 100;
public $precedence = array(
EXPR_NEGATIVE => 10,
EXPR_POSITIVE => 10,
EXPR_EXPONENT => 10,
EXPR_SINE => 9,
EXPR_COSINE => 9,
EXPR_TANGENS => 9,
EXPR_ARCSINE => 9,
EXPR_ARCCOS => 9,
EXPR_ARCTAN => 9,
EXPR_EXP => 9,
EXPR_LN => 9,
EXPR_ABS => 9,
EXPR_FLOOR => 9,
EXPR_TRUNC => 9,
EXPR_CEIL => 9,
EXPR_NOT => 9,
EXPR_SQRT => 9,
EXPR_POW => 8,
EXPR_TIMES => 7,
EXPR_DIVIDE => 7,
EXPR_MOD => 7,
EXPR_FMOD => 7,
EXPR_PLUS => 6,
EXPR_MINUS => 6,
EXPR_ROUND => 5,
EXPR_EQUALITY => 4,
EXPR_LESS => 4,
EXPR_GREATER => 4,
EXPR_LESSEQ => 4,
EXPR_GREATEREQ => 4,
EXPR_NOTEQ => 4,
EXPR_AND => 3,
EXPR_OR => 2,
EXPR_PI => 0,
EXPR_OPEN => -1,
EXPR_CLOSE => -1,
);
public $names = array(
EXPR_NEGATIVE => '-',
EXPR_POSITIVE => '+',
EXPR_NOT => 'not',
EXPR_TIMES => '*',
EXPR_DIVIDE => '/',
EXPR_MOD => 'mod',
EXPR_FMOD => 'fmod',
EXPR_PLUS => '+',
EXPR_MINUS => '-',
EXPR_ROUND => 'round',
EXPR_EQUALITY => '=',
EXPR_LESS => '<',
EXPR_GREATER => '>',
EXPR_LESSEQ => '<=',
EXPR_GREATEREQ => '>=',
EXPR_NOTEQ => '<>',
EXPR_AND => 'and',
EXPR_OR => 'or',
EXPR_EXPONENT => 'e',
EXPR_SINE => 'sin',
EXPR_COSINE => 'cos',
EXPR_TANGENS => 'tan',
EXPR_ARCSINE => 'asin',
EXPR_ARCCOS => 'acos',
EXPR_ARCTAN => 'atan',
EXPR_LN => 'ln',
EXPR_EXP => 'exp',
EXPR_ABS => 'abs',
EXPR_FLOOR => 'floor',
EXPR_TRUNC => 'trunc',
EXPR_CEIL => 'ceil',
EXPR_POW => '^',
EXPR_PI => 'pi',
EXPR_SQRT => 'sqrt',
);
public $words = array(
'mod' => EXPR_MOD,
'fmod' => EXPR_FMOD,
'and' => EXPR_AND,
'or' => EXPR_OR,
'not' => EXPR_NOT,
'round' => EXPR_ROUND,
'div' => EXPR_DIVIDE,
'e' => EXPR_EXPONENT,
'sin' => EXPR_SINE,
'cos' => EXPR_COSINE,
'tan' => EXPR_TANGENS,
'asin' => EXPR_ARCSINE,
'acos' => EXPR_ARCCOS,
'atan' => EXPR_ARCTAN,
'exp' => EXPR_EXP,
'ln' => EXPR_LN,
'abs' => EXPR_ABS,
'trunc' => EXPR_TRUNC,
'floor' => EXPR_FLOOR,
'ceil' => EXPR_CEIL,
'pi' => EXPR_PI,
'sqrt' => EXPR_SQRT,
);
/**
* Evaluate a mathematical expression
*
* The algorithm here is based on the infix to RPN algorithm given in
* http://montcs.bloomu.edu/~bobmon/Information/RPN/infix2rpn.shtml
* It's essentially the same as Dijkstra's shunting yard algorithm.
* @param $expr string
* @throws ExprError
* @return string
*/
public function doExpression( $expr ) {
$operands = array();
$operators = array();
# Unescape inequality operators
$expr = strtr( $expr, array( '&lt;' => '<', '&gt;' => '>',
'&minus;' => '-', '' => '-' ) );
$p = 0;
$end = strlen( $expr );
$expecting = 'expression';
$name = '';
while ( $p < $end ) {
if ( count( $operands ) > $this->maxStackSize || count( $operators ) > $this->maxStackSize ) {
throw new ExprError( 'stack_exhausted' );
}
$char = $expr[$p];
$char2 = substr( $expr, $p, 2 );
// Mega if-elseif-else construct
// Only binary operators fall through for processing at the bottom, the rest
// finish their processing and continue
// First the unlimited length classes
if ( false !== strpos( EXPR_WHITE_CLASS, $char ) ) {
// Whitespace
$p += strspn( $expr, EXPR_WHITE_CLASS, $p );
continue;
} elseif ( false !== strpos( EXPR_NUMBER_CLASS, $char ) ) {
// Number
if ( $expecting !== 'expression' ) {
throw new ExprError( 'unexpected_number' );
}
// Find the rest of it
$length = strspn( $expr, EXPR_NUMBER_CLASS, $p );
// Convert it to float, silently removing double decimal points
$operands[] = (float)substr( $expr, $p, $length );
$p += $length;
$expecting = 'operator';
continue;
} elseif ( ctype_alpha( $char ) ) {
// Word
// Find the rest of it
$remaining = substr( $expr, $p );
if ( !preg_match( '/^[A-Za-z]*/', $remaining, $matches ) ) {
// This should be unreachable
throw new ExprError( 'preg_match_failure' );
}
$word = strtolower( $matches[0] );
$p += strlen( $word );
// Interpret the word
if ( !isset( $this->words[$word] ) ) {
throw new ExprError( 'unrecognised_word', $word );
}
$op = $this->words[$word];
switch( $op ) {
// constant
case EXPR_EXPONENT:
if ( $expecting !== 'expression' ) {
continue;
}
$operands[] = exp( 1 );
$expecting = 'operator';
continue 2;
case EXPR_PI:
if ( $expecting !== 'expression' ) {
throw new ExprError( 'unexpected_number' );
}
$operands[] = pi();
$expecting = 'operator';
continue 2;
// Unary operator
case EXPR_NOT:
case EXPR_SINE:
case EXPR_COSINE:
case EXPR_TANGENS:
case EXPR_ARCSINE:
case EXPR_ARCCOS:
case EXPR_ARCTAN:
case EXPR_EXP:
case EXPR_LN:
case EXPR_ABS:
case EXPR_FLOOR:
case EXPR_TRUNC:
case EXPR_CEIL:
case EXPR_SQRT:
if ( $expecting !== 'expression' ) {
throw new ExprError( 'unexpected_operator', $word );
}
$operators[] = $op;
continue 2;
}
// Binary operator, fall through
$name = $word;
}
// Next the two-character operators
elseif ( $char2 === '<=' ) {
$name = $char2;
$op = EXPR_LESSEQ;
$p += 2;
} elseif ( $char2 === '>=' ) {
$name = $char2;
$op = EXPR_GREATEREQ;
$p += 2;
} elseif ( $char2 === '<>' || $char2 === '!=' ) {
$name = $char2;
$op = EXPR_NOTEQ;
$p += 2;
}
// Finally the single-character operators
elseif ( $char === '+' ) {
++$p;
if ( $expecting === 'expression' ) {
// Unary plus
$operators[] = EXPR_POSITIVE;
continue;
} else {
// Binary plus
$op = EXPR_PLUS;
}
} elseif ( $char === '-' ) {
++$p;
if ( $expecting === 'expression' ) {
// Unary minus
$operators[] = EXPR_NEGATIVE;
continue;
} else {
// Binary minus
$op = EXPR_MINUS;
}
} elseif ( $char === '*' ) {
$name = $char;
$op = EXPR_TIMES;
++$p;
} elseif ( $char === '/' ) {
$name = $char;
$op = EXPR_DIVIDE;
++$p;
} elseif ( $char === '^' ) {
$name = $char;
$op = EXPR_POW;
++$p;
} elseif ( $char === '(' ) {
if ( $expecting === 'operator' ) {
throw new ExprError( 'unexpected_operator', '(' );
}
$operators[] = EXPR_OPEN;
++$p;
continue;
} elseif ( $char === ')' ) {
$lastOp = end( $operators );
while ( $lastOp && $lastOp != EXPR_OPEN ) {
$this->doOperation( $lastOp, $operands );
array_pop( $operators );
$lastOp = end( $operators );
}
if ( $lastOp ) {
array_pop( $operators );
} else {
throw new ExprError( 'unexpected_closing_bracket' );
}
$expecting = 'operator';
++$p;
continue;
} elseif ( $char === '=' ) {
$name = $char;
$op = EXPR_EQUALITY;
++$p;
} elseif ( $char === '<' ) {
$name = $char;
$op = EXPR_LESS;
++$p;
} elseif ( $char === '>' ) {
$name = $char;
$op = EXPR_GREATER;
++$p;
} else {
throw new ExprError( 'unrecognised_punctuation', UtfNormal::cleanUp( $char ) );
}
// Binary operator processing
if ( $expecting === 'expression' ) {
throw new ExprError( 'unexpected_operator', $name );
}
// Shunting yard magic
$lastOp = end( $operators );
while ( $lastOp && $this->precedence[$op] <= $this->precedence[$lastOp] ) {
$this->doOperation( $lastOp, $operands );
array_pop( $operators );
$lastOp = end( $operators );
}
$operators[] = $op;
$expecting = 'expression';
}
// Finish off the operator array
while ( $op = array_pop( $operators ) ) {
if ( $op == EXPR_OPEN ) {
throw new ExprError( 'unclosed_bracket' );
}
$this->doOperation( $op, $operands );
}
return implode( "<br />\n", $operands );
}
/**
* @param $op int
* @param $stack array
* @throws ExprError
*/
public function doOperation( $op, &$stack ) {
switch ( $op ) {
case EXPR_NEGATIVE:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = -$arg;
break;
case EXPR_POSITIVE:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
break;
case EXPR_TIMES:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = $left * $right;
break;
case EXPR_DIVIDE:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
if ( !$right ) {
throw new ExprError( 'division_by_zero', $this->names[$op] );
}
$stack[] = $left / $right;
break;
case EXPR_MOD:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = (int)array_pop( $stack );
$left = (int)array_pop( $stack );
if ( !$right ) {
throw new ExprError( 'division_by_zero', $this->names[$op] );
}
$stack[] = $left % $right;
break;
case EXPR_FMOD:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = (double)array_pop( $stack );
$left = (double)array_pop( $stack );
if ( !$right ) {
throw new ExprError( 'division_by_zero', $this->names[$op] );
}
$stack[] = fmod( $left, $right );
break;
case EXPR_PLUS:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = $left + $right;
break;
case EXPR_MINUS:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = $left - $right;
break;
case EXPR_AND:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left && $right ) ? 1 : 0;
break;
case EXPR_OR:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left || $right ) ? 1 : 0;
break;
case EXPR_EQUALITY:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left == $right ) ? 1 : 0;
break;
case EXPR_NOT:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = ( !$arg ) ? 1 : 0;
break;
case EXPR_ROUND:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$digits = (int)array_pop( $stack );
$value = array_pop( $stack );
$stack[] = round( $value, $digits );
break;
case EXPR_LESS:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left < $right ) ? 1 : 0;
break;
case EXPR_GREATER:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left > $right ) ? 1 : 0;
break;
case EXPR_LESSEQ:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left <= $right ) ? 1 : 0;
break;
case EXPR_GREATEREQ:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left >= $right ) ? 1 : 0;
break;
case EXPR_NOTEQ:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = ( $left != $right ) ? 1 : 0;
break;
case EXPR_EXPONENT:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
$stack[] = $left * pow( 10, $right );
break;
case EXPR_SINE:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = sin( $arg );
break;
case EXPR_COSINE:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = cos( $arg );
break;
case EXPR_TANGENS:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = tan( $arg );
break;
case EXPR_ARCSINE:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
if ( $arg < -1 || $arg > 1 ) {
throw new ExprError( 'invalid_argument', $this->names[$op] );
}
$stack[] = asin( $arg );
break;
case EXPR_ARCCOS:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
if ( $arg < -1 || $arg > 1 ) {
throw new ExprError( 'invalid_argument', $this->names[$op] );
}
$stack[] = acos( $arg );
break;
case EXPR_ARCTAN:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = atan( $arg );
break;
case EXPR_EXP:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = exp( $arg );
break;
case EXPR_LN:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
if ( $arg <= 0 ) {
throw new ExprError( 'invalid_argument_ln', $this->names[$op] );
}
$stack[] = log( $arg );
break;
case EXPR_ABS:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = abs( $arg );
break;
case EXPR_FLOOR:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = floor( $arg );
break;
case EXPR_TRUNC:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = (int)$arg;
break;
case EXPR_CEIL:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$stack[] = ceil( $arg );
break;
case EXPR_POW:
if ( count( $stack ) < 2 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$right = array_pop( $stack );
$left = array_pop( $stack );
if ( false === ( $stack[] = pow( $left, $right ) ) ) {
throw new ExprError( 'division_by_zero', $this->names[$op] );
}
break;
case EXPR_SQRT:
if ( count( $stack ) < 1 ) {
throw new ExprError( 'missing_operand', $this->names[$op] );
}
$arg = array_pop( $stack );
$result = sqrt( $arg );
if ( is_nan( $result ) ) {
throw new ExprError( 'not_a_number', $this->names[$op] );
}
$stack[] = $result;
break;
default:
// Should be impossible to reach here.
throw new ExprError( 'unknown_error' );
}
}
}