mediawiki-extensions-Parser.../includes/ExprParser.php
RazeSoldier d258457e01 Use "break" instead of "continue" inside a switch
"continue" statements in a switch are equivalent to "break". In PHP 7.3, will generate a warning.

Also change the indentation.

Bug: T206977
Change-Id: I8ad0ef6508e73bcca7dabfe2e88d661dd409bdfb
2018-10-15 15:45:06 +00:00

674 lines
18 KiB
PHP
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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
/**
* This program 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.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
use UtfNormal\Validator;
// 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 ExprParser {
public $maxStackSize = 100;
public $precedence = [
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 = [
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 = [
'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 string $expr
* @throws ExprError
* @return string
*/
public function doExpression( $expr ) {
$operands = [];
$operators = [];
# Unescape inequality operators
$expr = strtr( $expr, [ '&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' ) {
break;
}
$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;
} 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;
} 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 {
$utfExpr = Validator::cleanUp( substr( $expr, $p ) );
throw new ExprError( 'unrecognised_punctuation', mb_substr( $utfExpr, 0, 1 ) );
}
// 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
// @codingStandardsIgnoreStart
while ( $op = array_pop( $operators ) ) {
// @codingStandardsIgnoreEnd
if ( $op == EXPR_OPEN ) {
throw new ExprError( 'unclosed_bracket' );
}
$this->doOperation( $op, $operands );
}
return implode( "<br />\n", $operands );
}
/**
* @param int $op
* @param array &$stack
* @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 );
$result = pow( $left, $right );
if ( $result === false ) {
throw new ExprError( 'division_by_zero', $this->names[$op] );
}
$stack[] = $result;
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' );
}
}
}