| 1 |
<?php |
| 2 |
/** |
| 3 |
* EvalMath - Safely evaluate math expressions |
| 4 |
* |
| 5 |
* Based on EvalMath by Miles Kaufmann, with modifications by Petr Skoda. |
| 6 |
* @link https://github.com/moodle/moodle/blob/4efc3d4096bc1d29e9d77f9af7194b2babfa2821/lib/evalmath/evalmath.class.php |
| 7 |
* |
| 8 |
* @package TablePress |
| 9 |
* @subpackage Formulas |
| 10 |
* @author Miles Kaufmann, Petr Skoda, Tobias Bäthge |
| 11 |
* @since 1.0.0 |
| 12 |
*/ |
| 13 |
|
| 14 |
// Prohibit direct script loading. |
| 15 |
defined( 'ABSPATH' ) || die( 'No direct script access allowed!' ); |
| 16 |
|
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/** |
| 18 |
* Class to safely evaluate math expressions. |
| 19 |
* @package TablePress |
| 20 |
* @subpackage Formulas |
| 21 |
* @since 1.0.0 |
| 22 |
*/ |
| 23 |
class EvalMath { |
| 24 |
|
| 25 |
/** |
| 26 |
* Pattern used for a valid function or variable name. |
| 27 |
* |
| 28 |
* Note, var and func names are case insensitive. |
| 29 |
* |
| 30 |
* @since 1.0.0 |
| 31 |
* @var string |
| 32 |
*/ |
| 33 |
protected static $name_pattern = '[a-z][a-z0-9_]*'; |
| 34 |
|
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/** |
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* Whether to suppress errors and warnings. |
| 37 |
* |
| 38 |
* @since 1.0.0 |
| 39 |
* @var boolean |
| 40 |
*/ |
| 41 |
public $suppress_errors = false; |
| 42 |
|
| 43 |
/** |
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* The last error message that was raised. |
| 45 |
* |
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* @since 1.0.0 |
| 47 |
* @var string |
| 48 |
*/ |
| 49 |
public $last_error = ''; |
| 50 |
|
| 51 |
/** |
| 52 |
* Variables (including constants). |
| 53 |
* |
| 54 |
* @since 1.0.0 |
| 55 |
* @var array |
| 56 |
*/ |
| 57 |
protected $variables = array(); |
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|
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/** |
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* User-defined functions. |
| 61 |
* |
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* @since 1.0.0 |
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* @var array |
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*/ |
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protected $functions = array(); |
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|
| 67 |
/** |
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* Constants. |
| 69 |
* |
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* @since 1.0.0 |
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* @var array |
| 72 |
*/ |
| 73 |
protected $constants = array(); |
| 74 |
|
| 75 |
/** |
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* Built-in functions. |
| 77 |
* |
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* @since 1.0.0 |
| 79 |
* @var array |
| 80 |
*/ |
| 81 |
protected $builtin_functions = array( |
| 82 |
'sin', 'sinh', 'arcsin', 'asin', 'arcsinh', 'asinh', |
| 83 |
'cos', 'cosh', 'arccos', 'acos', 'arccosh', 'acosh', |
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'tan', 'tanh', 'arctan', 'atan', 'arctanh', 'atanh', |
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'sqrt', 'abs', 'ln', 'log10', 'exp', 'floor', 'ceil', |
| 86 |
); |
| 87 |
|
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/** |
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* Emulated functions. |
| 90 |
* |
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* @since 1.0.0 |
| 92 |
* @var array |
| 93 |
*/ |
| 94 |
protected $calc_functions = array( |
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'average' => array( -1 ), |
| 96 |
'mean' => array( -1 ), |
| 97 |
'median' => array( -1 ), |
| 98 |
'mode' => array( -1 ), |
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'range' => array( -1 ), |
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'max' => array( -1 ), |
| 101 |
'min' => array( -1 ), |
| 102 |
'mod' => array( 2 ), |
| 103 |
'pi' => array( 0 ), |
| 104 |
'power' => array( 2 ), |
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'log' => array( 1, 2 ), |
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'round' => array( 1, 2 ), |
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'number_format' => array( 1, 2 ), |
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'number_format_eu' => array( 1, 2 ), |
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'sum' => array( -1 ), |
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'product' => array( -1 ), |
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'rand_int' => array( 2 ), |
| 112 |
'rand_float' => array( 0 ), |
| 113 |
'arctan2' => array( 2 ), |
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'atan2' => array( 2 ), |
| 115 |
'if' => array( 3 ), |
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'not' => array( 1 ), |
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'and' => array( -1 ), |
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'or' => array( -1 ), |
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); |
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|
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/** |
| 122 |
* Class constructor. |
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* |
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* @since 1.0.0 |
| 125 |
*/ |
| 126 |
public function __construct() { |
| 127 |
// Sets default constants. |
| 128 |
$this->variables['pi'] = pi(); |
| 129 |
$this->variables['e'] = exp( 1 ); |
| 130 |
} |
| 131 |
|
| 132 |
/** |
| 133 |
* Evaluate a math expression without checking it for variable or function assignments. |
| 134 |
* |
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* @since 1.0.0 |
| 136 |
* |
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* @param string $expression The expression that shall be evaluated. |
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* @return string Evaluated expression. |
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*/ |
| 140 |
public function evaluate( $expression ) { |
| 141 |
return $this->pfx( $this->nfx( $expression ) ); |
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} |
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|
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/** |
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* Evaluate a math expression or formula, and check it for variable an function assignments. |
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* |
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* @since 1.0.0 |
| 148 |
* |
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* @param string $expression The expression that shall be evaluated. |
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* @return string|bool Evaluated expression, true on successful function assignment, or false on error. |
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*/ |
| 152 |
public function assign_and_evaluate( $expression ) { |
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$this->last_error = ''; |
| 154 |
$expression = trim( $expression ); |
| 155 |
$expression = rtrim( $expression, ';' ); |
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|
| 157 |
// Is the expression a variable assignment? |
| 158 |
if ( 1 === preg_match( '/^\s*(' . self::$name_pattern . ')\s*=\s*(.+)$/', $expression, $matches ) ) { |
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// Make sure we're not assigning to a constant. |
| 160 |
if ( in_array( $matches[1], $this->constants, true ) ) { |
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return $this->raise_error( 'cannot_assign_to_constant', $matches[1] ); |
| 162 |
} |
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// Evaluate the assignment. |
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$tmp = $this->pfx( $this->nfx( $matches[2] ) ); |
| 165 |
if ( fales === $tmp ) { |
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return false; |
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} |
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// If it could be evaluated, add it to the variable array, |
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$this->variables[ $matches[1] ] = $tmp; |
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// and return the resulting value. |
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return $tmp; |
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|
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// Is the expression a function assignment? |
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} elseif ( 1 === preg_match( '/^\s*(' . self::$name_pattern . ')\s*\(\s*(' . self::$name_pattern . '(?:\s*,\s*' . self::$name_pattern . ')*)\s*\)\s*=\s*(.+)$/', $expression, $matches ) ) { |
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// Get the function name. |
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$function_name = $matches[1]; |
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// Make sure it isn't a built-in function -- we can't redefine those. |
| 178 |
if ( in_array( $matches[1], $this->builtin_functions, true ) ) { |
| 179 |
return $this->raise_error( 'cannot_redefine_builtin_function', $matches[1] ); |
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} |
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// Get the function arguments after removing all whitespace. |
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$matches[2] = str_replace( array( "\n", "\r", "\t", ' ' ), '', $matches[2] ); |
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$args = explode( ',', $matches[2] ); |
| 184 |
|
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// Convert the function definition to postfix notation. |
| 186 |
$stack = $this->nfx( $matches[3] ); |
| 187 |
if ( false === $stack ) { |
| 188 |
return false; |
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} |
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// Freeze the state of the non-argument variables. |
| 191 |
for ( $i = 0; $i < count( $stack ); $i++ ) { |
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$token = $stack[ $i ]; |
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if ( 1 === preg_match( '/^' . self::$name_pattern . '$/', $token ) && ! in_array( $token, $args, true ) ) { |
| 194 |
if ( array_key_exists( $token, $this->variables ) ) { |
| 195 |
$stack[ $i ] = $this->variables[ $token ]; |
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} else { |
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return $this->raise_error( 'undefined_variable_in_function_definition', $token ); |
| 198 |
} |
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} |
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} |
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$this->functions[ $function_name ] = array( 'args' => $args, 'func' => $stack ); |
| 202 |
return true; |
| 203 |
|
| 204 |
// No variable or function assignment, so straight-up evaluation. |
| 205 |
} else { |
| 206 |
return $this->evaluate( $expression ); |
| 207 |
} |
| 208 |
} |
| 209 |
|
| 210 |
/** |
| 211 |
* Return all user-defined variables and values. |
| 212 |
* |
| 213 |
* @since 1.0.0 |
| 214 |
* |
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* @return array User-defined variables and values. |
| 216 |
*/ |
| 217 |
public function variables() { |
| 218 |
return $this->variables; |
| 219 |
} |
| 220 |
|
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/** |
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* Return all user-defined functions with their arguments. |
| 223 |
* |
| 224 |
* @since 1.0.0 |
| 225 |
* |
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* @return array User-defined functions. |
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*/ |
| 228 |
public function functions() { |
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$output = array(); |
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foreach ( $this->functions as $name => $data ) { |
| 231 |
$output[] = $name . '( ' . implode( ', ', $data['args'] ) . ' )'; |
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} |
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return $output; |
| 234 |
} |
| 235 |
|
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/* |
| 237 |
* Internal methods. |
| 238 |
*/ |
| 239 |
|
| 240 |
/** |
| 241 |
* Convert infix to postfix notation. |
| 242 |
* |
| 243 |
* @since 1.0.0 |
| 244 |
* |
| 245 |
* @param string $expression Math expression that shall be converted. |
| 246 |
* @return array|false Converted expression or false on error. |
| 247 |
*/ |
| 248 |
protected function nfx( $expression ) { |
| 249 |
$index = 0; |
| 250 |
$stack = new EvalMath_Stack; |
| 251 |
$output = array(); // postfix form of expression, to be passed to pfx() |
| 252 |
$expression = trim( strtolower( $expression ) ); |
| 253 |
|
| 254 |
$ops = array( '+', '-', '*', '/', '^', '_', '>', '<', '=' ); |
| 255 |
// Right-associative operator? |
| 256 |
$ops_r = array( '+' => 0, '-' => 0, '*' => 0, '/' => 0, '^' => 1, '>' => 0, '<' => 0, '=' => 0 ); |
| 257 |
// Operator precedence. |
| 258 |
$ops_p = array( '+' => 0, '-' => 0, '*' => 1, '/' => 1, '_' => 1, '^' => 2, '>' => 0, '<' => 0, '=' => 0 ); |
| 259 |
|
| 260 |
// We use this in syntax-checking the expression and determining when a - (minus) is a negation. |
| 261 |
$expecting_operator = false; |
| 262 |
|
| 263 |
// Make sure the characters are all good. |
| 264 |
if ( 1 === preg_match( '/[^\w\s+*^\/()\.,-<>=]/', $expression, $matches ) ) { |
| 265 |
return $this->raise_error( 'illegal_character_general', $matches[0] ); |
| 266 |
} |
| 267 |
|
| 268 |
// Infinite Loop for the conversion. |
| 269 |
while ( true ) { |
| 270 |
// Get the first character at the current index. |
| 271 |
$op = substr( $expression, $index, 1 ); |
| 272 |
// Find out if we're currently at the beginning of a number/variable/function/parenthesis/operand. |
| 273 |
$ex = preg_match( '/^(' . self::$name_pattern . '\(?|\d+(?:\.\d*)?(?:(e[+-]?)\d*)?|\.\d+|\()/', substr( $expression, $index ), $match ); |
| 274 |
|
| 275 |
// Is it a negation instead of a minus (in a subtraction)? |
| 276 |
if ( '-' === $op && ! $expecting_operator ) { |
| 277 |
// Put a negation on the stack. |
| 278 |
$stack->push( '_' ); |
| 279 |
$index++; |
| 280 |
} elseif ( '_' === $op ) { |
| 281 |
// We have to explicitly deny underscores (as they mean negation), because they are legal on the stack. |
| 282 |
return $this->raise_error( 'illegal_character_underscore' ); |
| 283 |
|
| 284 |
// Are we putting an operator on the stack? |
| 285 |
} elseif ( ( in_array( $op, $ops, true ) || $ex ) && $expecting_operator ) { |
| 286 |
// Are we expecting an operator but have a number/variable/function/opening parethesis? |
| 287 |
if ( $ex ) { |
| 288 |
// It's an implicit multiplication. |
| 289 |
$op = '*'; |
| 290 |
$index--; |
| 291 |
} |
| 292 |
// Heart of the algorithm: |
| 293 |
while ( $stack->count > 0 && ( $o2 = $stack->last() ) && in_array( $o2, $ops, true ) && ( $ops_r[ $op ] ? $ops_p[ $op ] < $ops_p[ $o2 ] : $ops_p[ $op ] <= $ops_p[ $o2 ] ) ) { |
| 294 |
// Pop stuff off the stack into the output. |
| 295 |
$output[] = $stack->pop(); |
| 296 |
} |
| 297 |
// Many thanks: https://en.wikipedia.org/wiki/Reverse_Polish_notation |
| 298 |
$stack->push( $op ); // finally put OUR operator onto the stack |
| 299 |
$index++; |
| 300 |
$expecting_operator = false; |
| 301 |
|
| 302 |
// Ready to close a parenthesis? |
| 303 |
} elseif ( ')' === $op && $expecting_operator ) { |
| 304 |
// Pop off the stack back to the last (. |
| 305 |
while ( '(' !== ( $o2 = $stack->pop() ) ) { |
| 306 |
if ( is_null( $o2 ) ) { |
| 307 |
return $this->raise_error( 'unexpected_closing_bracket' ); |
| 308 |
} else { |
| 309 |
$output[] = $o2; |
| 310 |
} |
| 311 |
} |
| 312 |
|
| 313 |
// Did we just close a function? |
| 314 |
if ( 1 === preg_match( '/^(' . self::$name_pattern . ')\($/', $stack->last( 2 ), $matches ) ) { |
| 315 |
// Get the function name. |
| 316 |
$function_name = $matches[1]; |
| 317 |
// See how many arguments there were (cleverly stored on the stack, thank you). |
| 318 |
$arg_count = $stack->pop(); |
| 319 |
$fn = $stack->pop(); |
| 320 |
// Send function to output. |
| 321 |
$output[] = array( 'function_name' => $function_name, 'arg_count' => $arg_count ); |
| 322 |
// Check the argument count, depending on what type of function we have. |
| 323 |
if ( in_array( $function_name, $this->builtin_functions, true ) ) { |
| 324 |
// Built-in functions. |
| 325 |
if ( $arg_count > 1 ) { |
| 326 |
$error_data = array( 'expected' => 1, 'given' => $arg_count ); |
| 327 |
return $this->raise_error( 'wrong_number_of_arguments', $error_data ); |
| 328 |
} |
| 329 |
} elseif ( array_key_exists( $function_name, $this->calc_functions ) ) { |
| 330 |
// Calc-emulation functions. |
| 331 |
$counts = $this->calc_functions[ $function_name ]; |
| 332 |
if ( in_array( -1, $counts, true ) && $arg_count > 0 ) { |
| 333 |
// Everything is fine, we expected an indefinite number arguments and got some. |
| 334 |
} elseif ( ! in_array( $arg_count, $counts, true ) ) { |
| 335 |
$error_data = array( 'expected' => implode( '/', $this->calc_functions[ $function_name ] ), 'given' => $arg_count ); |
| 336 |
return $this->raise_error( 'wrong_number_of_arguments', $error_data ); |
| 337 |
} |
| 338 |
} elseif ( array_key_exists( $function_name, $this->functions ) ) { |
| 339 |
// User-defined functions. |
| 340 |
if ( count( $this->functions[ $function_name ]['args'] ) !== $arg_count ) { |
| 341 |
$error_data = array( 'expected' => count( $this->functions[ $function_name ]['args'] ), 'given' => $arg_count ); |
| 342 |
return $this->raise_error( 'wrong_number_of_arguments', $error_data ); |
| 343 |
} |
| 344 |
} else { |
| 345 |
// Did we somehow push a non-function on the stack? This should never happen. |
| 346 |
return $this->raise_error( 'internal_error' ); |
| 347 |
} |
| 348 |
} |
| 349 |
$index++; |
| 350 |
|
| 351 |
// Did we just finish a function argument? |
| 352 |
} elseif ( ',' === $op && $expecting_operator ) { |
| 353 |
while ( '(' !== ( $o2 = $stack->pop() ) ) { |
| 354 |
if ( is_null( $o2 ) ) { |
| 355 |
// Oops, never had a (. |
| 356 |
return $this->raise_error( 'unexpected_comma' ); |
| 357 |
} else { |
| 358 |
// Pop the argument expression stuff and push onto the output. |
| 359 |
$output[] = $o2; |
| 360 |
} |
| 361 |
} |
| 362 |
// Make sure there was a function. |
| 363 |
if ( 0 === preg_match( '/^(' . self::$name_pattern . ')\($/', $stack->last( 2 ), $matches ) ) { |
| 364 |
return $this->raise_error( 'unexpected_comma' ); |
| 365 |
} |
| 366 |
// Increment the argument count. |
| 367 |
$stack->push( $stack->pop() + 1 ); |
| 368 |
// Put the ( back on, we'll need to pop back to it again. |
| 369 |
$stack->push( '(' ); |
| 370 |
$index++; |
| 371 |
$expecting_operator = false; |
| 372 |
|
| 373 |
} elseif ( '(' === $op && ! $expecting_operator ) { |
| 374 |
$stack->push( '(' ); // That was easy. |
| 375 |
$index++; |
| 376 |
|
| 377 |
// Do we now have a function/variable/number? |
| 378 |
} elseif ( $ex && ! $expecting_operator ) { |
| 379 |
$expecting_operator = true; |
| 380 |
$value = $match[1]; |
| 381 |
// May be a function, or variable with implicit multiplication against parentheses... |
| 382 |
if ( 1 === preg_match( '/^(' . self::$name_pattern . ')\($/', $value, $matches ) ) { |
| 383 |
// Is it a function? |
| 384 |
if ( in_array( $matches[1], $this->builtin_functions, true ) || array_key_exists( $matches[1], $this->functions ) || array_key_exists( $matches[1], $this->calc_functions ) ) { |
| 385 |
$stack->push( $value ); |
| 386 |
$stack->push( 1 ); |
| 387 |
$stack->push( '(' ); |
| 388 |
$expecting_operator = false; |
| 389 |
// It's a variable with implicit multiplication. |
| 390 |
} else { |
| 391 |
$value = $matches[1]; |
| 392 |
$output[] = $value; |
| 393 |
} |
| 394 |
} else { |
| 395 |
// It's a plain old variable or number. |
| 396 |
$output[] = $value; |
| 397 |
} |
| 398 |
$index += strlen( $value ); |
| 399 |
|
| 400 |
} elseif ( ')' === $op ) { |
| 401 |
// It could be only custom function with no arguments or a general error. |
| 402 |
if ( '(' !== $stack->last() || 1 !== $stack->last( 2 ) ) { |
| 403 |
return $this->raise_error( 'unexpected_closing_bracket' ); |
| 404 |
} |
| 405 |
// Did we just close a function? |
| 406 |
if ( 1 === preg_match( '/^(' . self::$name_pattern . ')\($/', $stack->last( 3 ), $matches ) ) { |
| 407 |
$stack->pop(); // ( |
| 408 |
$stack->pop(); // 1 |
| 409 |
$fn = $stack->pop(); |
| 410 |
// Get the function name. |
| 411 |
$function_name = $matches[1]; |
| 412 |
if ( isset( $this->calc_functions[ $function_name ] ) ) { |
| 413 |
// Custom calc-emulation function. |
| 414 |
$counts = $this->calc_functions[ $function_name ]; |
| 415 |
} else { |
| 416 |
// Default count for built-in functions. |
| 417 |
$counts = array( 1 ); |
| 418 |
} |
| 419 |
if ( ! in_array( 0, $counts, true ) ) { |
| 420 |
$error_data = array( 'expected' => $counts, 'given' => 0 ); |
| 421 |
return $this->raise_error( 'wrong_number_of_arguments', $error_data ); |
| 422 |
} |
| 423 |
// Send function to output. |
| 424 |
$output[] = array( 'function_name' => $function_name, 'arg_count' => 0 ); |
| 425 |
$index++; |
| 426 |
$expecting_operator = true; |
| 427 |
} else { |
| 428 |
return $this->raise_error( 'unexpected_closing_bracket' ); |
| 429 |
} |
| 430 |
|
| 431 |
// Miscellaneous error checking. |
| 432 |
} elseif ( in_array( $op, $ops, true ) && ! $expecting_operator ) { |
| 433 |
return $this->raise_error( 'unexpected_operator', $op ); |
| 434 |
|
| 435 |
// I don't even want to know what you did to get here. |
| 436 |
} else { |
| 437 |
return $this->raise_error( 'an_unexpected_error_occurred' ); |
| 438 |
} |
| 439 |
|
| 440 |
if ( strlen( $expression ) === $index ) { |
| 441 |
// Did we end with an operator? Bad. |
| 442 |
if ( in_array( $op, $ops, true ) ) { |
| 443 |
return $this->raise_error( 'operator_lacks_operand', $op ); |
| 444 |
} else { |
| 445 |
break; |
| 446 |
} |
| 447 |
} |
| 448 |
|
| 449 |
// Step the index past whitespace (pretty much turns whitespace into implicit multiplication if no operator is there). |
| 450 |
while ( ' ' === substr( $expression, $index, 1 ) ) { |
| 451 |
$index++; |
| 452 |
} |
| 453 |
} // while ( true ) |
| 454 |
|
| 455 |
// Pop everything off the stack and push onto output. |
| 456 |
while ( ! is_null( $op = $stack->pop() ) ) { |
| 457 |
if ( '(' === $op ) { |
| 458 |
// If there are (s on the stack, ()s were unbalanced. |
| 459 |
return $this->raise_error( 'expecting_a_closing_bracket' ); |
| 460 |
} |
| 461 |
$output[] = $op; |
| 462 |
} |
| 463 |
|
| 464 |
return $output; |
| 465 |
} |
| 466 |
|
| 467 |
/** |
| 468 |
* Evaluate postfix notation. |
| 469 |
* |
| 470 |
* @since 1.0.0 |
| 471 |
* |
| 472 |
* @param array|false $tokens [description] |
| 473 |
* @param array $variables Optional. [description] |
| 474 |
* @return mixed [description] |
| 475 |
*/ |
| 476 |
protected function pfx( $tokens, array $variables = array() ) { |
| 477 |
if ( false === $tokens ) { |
| 478 |
return false; |
| 479 |
} |
| 480 |
|
| 481 |
$stack = new EvalMath_Stack; |
| 482 |
|
| 483 |
foreach ( $tokens as $token ) { |
| 484 |
// If the token is a function, pop arguments off the stack, hand them to the function, and push the result back on. |
| 485 |
if ( is_array( $token ) ) { // it's a function! |
| 486 |
$function_name = $token['function_name']; |
| 487 |
$count = $token['arg_count']; |
| 488 |
|
| 489 |
// Built-in function. |
| 490 |
if ( in_array( $function_name, $this->builtin_functions, true ) ) { |
| 491 |
$op1 = $stack->pop(); |
| 492 |
if ( is_null( $op1 ) ) { |
| 493 |
return $this->raise_error( 'internal_error' ); |
| 494 |
} |
| 495 |
// For the "arc" trigonometric synonyms. |
| 496 |
$function_name = preg_replace( '/^arc/', 'a', $function_name ); |
| 497 |
// Rewrite "ln" (only allows one argument) to "log" (natural logarithm). |
| 498 |
if ( 'ln' === $function_name ) { |
| 499 |
$function_name = 'log'; |
| 500 |
} |
| 501 |
// Perfectly safe eval(). |
| 502 |
eval( '$stack->push( ' . $function_name . '( $op1 ) );' ); |
| 503 |
|
| 504 |
// Calc-emulation function. |
| 505 |
} elseif ( array_key_exists( $function_name, $this->calc_functions ) ) { |
| 506 |
// Get function arguments. |
| 507 |
$args = array(); |
| 508 |
for ( $i = $count - 1; $i >= 0; $i-- ) { |
| 509 |
$arg = $stack->pop(); |
| 510 |
if ( is_null( $arg ) ) { |
| 511 |
return $this->raise_error( 'internal_error' ); |
| 512 |
} else { |
| 513 |
$args[] = $arg; |
| 514 |
} |
| 515 |
} |
| 516 |
// Rewrite some functions to their synonyms. |
| 517 |
if ( 'if' === $function_name ) { |
| 518 |
$function_name = 'func_if'; |
| 519 |
} elseif ( 'not' === $function_name ) { |
| 520 |
$function_name = 'func_not'; |
| 521 |
} elseif ( 'and' === $function_name ) { |
| 522 |
$function_name = 'func_and'; |
| 523 |
} elseif ( 'or' === $function_name ) { |
| 524 |
$function_name = 'func_or'; |
| 525 |
} elseif ( 'mean' === $function_name ) { |
| 526 |
$function_name = 'average'; |
| 527 |
} elseif ( 'arctan2' === $function_name ) { |
| 528 |
$function_name = 'atan2'; |
| 529 |
} |
| 530 |
$result = call_user_func_array( array( 'EvalMath_Functions', $function_name ), array_reverse( $args ) ); |
| 531 |
if ( false === $result ) { |
| 532 |
return $this->raise_error( 'internal_error' ); |
| 533 |
} |
| 534 |
$stack->push( $result ); |
| 535 |
|
| 536 |
// User-defined function. |
| 537 |
} elseif ( array_key_exists( $function_name, $this->functions ) ) { |
| 538 |
// Get function arguments. |
| 539 |
$args = array(); |
| 540 |
for ( $i = count( $this->functions[ $function_name ]['args'] ) - 1; $i >= 0; $i-- ) { |
| 541 |
$arg = $stack->pop(); |
| 542 |
if ( is_null( $arg ) ) { |
| 543 |
return $this->raise_error( 'internal_error' ); |
| 544 |
} else { |
| 545 |
$args[ $this->functions[ $function_name ]['args'][ $i ] ] = $arg; |
| 546 |
} |
| 547 |
} |
| 548 |
// yay... recursion! |
| 549 |
$stack->push( $this->pfx( $this->functions[ $function_name ]['func'], $args ) ); |
| 550 |
} |
| 551 |
|
| 552 |
// If the token is a binary operator, pop two values off the stack, do the operation, and push the result back on. |
| 553 |
} elseif ( in_array( $token, array( '+', '-', '*', '/', '^', '>', '<', '=' ), true ) ) { |
| 554 |
$op2 = $stack->pop(); |
| 555 |
if ( is_null( $op2 ) ) { |
| 556 |
return $this->raise_error( 'internal_error' ); |
| 557 |
} |
| 558 |
$op1 = $stack->pop(); |
| 559 |
if ( is_null( $op1 ) ) { |
| 560 |
return $this->raise_error( 'internal_error' ); |
| 561 |
} |
| 562 |
switch ( $token ) { |
| 563 |
case '+': |
| 564 |
$stack->push( $op1 + $op2 ); |
| 565 |
break; |
| 566 |
case '-': |
| 567 |
$stack->push( $op1 - $op2 ); |
| 568 |
break; |
| 569 |
case '*': |
| 570 |
$stack->push( $op1 * $op2 ); |
| 571 |
break; |
| 572 |
case '/': |
| 573 |
if ( 0 === $op2 || '0' === $op2 ) { |
| 574 |
return $this->raise_error( 'division_by_zero' ); |
| 575 |
} |
| 576 |
$stack->push( $op1 / $op2 ); |
| 577 |
break; |
| 578 |
case '^': |
| 579 |
$stack->push( pow( $op1, $op2 ) ); |
| 580 |
break; |
| 581 |
case '>': |
| 582 |
$stack->push( (int) ( $op1 > $op2 ) ); |
| 583 |
break; |
| 584 |
case '<': |
| 585 |
$stack->push( (int) ( $op1 < $op2 ) ); |
| 586 |
break; |
| 587 |
case '=': |
| 588 |
$stack->push( (int) ( $op1 == $op2 ) ); // Don't use === as the variable type can differ (int/double/bool). |
| 589 |
break; |
| 590 |
} |
| 591 |
|
| 592 |
// If the token is a unary operator, pop one value off the stack, do the operation, and push it back on. |
| 593 |
} elseif ( '_' === $token ) { |
| 594 |
$stack->push( -1 * $stack->pop() ); |
| 595 |
|
| 596 |
// If the token is a number or variable, push it on the stack. |
| 597 |
} else { |
| 598 |
if ( is_numeric( $token ) ) { |
| 599 |
$stack->push( $token ); |
| 600 |
} elseif ( array_key_exists( $token, $this->variables ) ) { |
| 601 |
$stack->push( $this->variables[ $token ] ); |
| 602 |
} elseif ( array_key_exists( $token, $variables ) ) { |
| 603 |
$stack->push( $variables[ $token ] ); |
| 604 |
} else { |
| 605 |
return $this->raise_error( 'undefined_variable', $token ); |
| 606 |
} |
| 607 |
} |
| 608 |
} |
| 609 |
// When we're out of tokens, the stack should have a single element, the final result. |
| 610 |
if ( 1 !== $stack->count ) { |
| 611 |
return $this->raise_error( 'internal_error' ); |
| 612 |
} |
| 613 |
return $stack->pop(); |
| 614 |
} |
| 615 |
|
| 616 |
/** |
| 617 |
* Raise an error. |
| 618 |
* |
| 619 |
* @since 1.0.0 |
| 620 |
* |
| 621 |
* @param string $message Error message. |
| 622 |
* @param array|string $error_data Optional. Additional error data. |
| 623 |
* @return bool False, to stop evaluation. |
| 624 |
*/ |
| 625 |
protected function raise_error( $message, $error_data = null ) { |
| 626 |
$this->last_error = $this->get_error_string( $message, $error_data ); |
| 627 |
return false; |
| 628 |
} |
| 629 |
|
| 630 |
|
| 631 |
/** |
| 632 |
* Get a translated string for an error message. |
| 633 |
* |
| 634 |
* @since 1.0.0 |
| 635 |
* |
| 636 |
* @link https://github.com/moodle/moodle/blob/13264f35057d2f37374ec3e0e8ad4070f4676bd7/lang/en/mathslib.php |
| 637 |
* @link https://github.com/moodle/moodle/blob/8e54ce9717c19f768b95f4332f70e3180ffafc46/lib/moodlelib.php#L6323 |
| 638 |
* |
| 639 |
* @param string $identifier Identifier of the string. |
| 640 |
* @param array|string $error_data Optional. Additional error data. |
| 641 |
* @return string Translated string. |
| 642 |
*/ |
| 643 |
protected function get_error_string( $identifier, $error_data = null ) { |
| 644 |
$strings = array(); |
| 645 |
$strings['an_unexpected_error_occurred'] = 'an unexpected error occurred'; |
| 646 |
$strings['cannot_assign_to_constant'] = 'cannot assign to constant \'{$error_data}\''; |
| 647 |
$strings['cannot_redefine_builtin_function'] = 'cannot redefine built-in function \'{$error_data}()\''; |
| 648 |
$strings['division_by_zero'] = 'division by zero'; |
| 649 |
$strings['expecting_a_closing_bracket'] = 'expecting a closing bracket'; |
| 650 |
$strings['illegal_character_general'] = 'illegal character \'{$error_data}\''; |
| 651 |
$strings['illegal_character_underscore'] = 'illegal character \'_\''; |
| 652 |
$strings['internal_error'] = 'internal error'; |
| 653 |
$strings['operator_lacks_operand'] = 'operator \'{$error_data}\' lacks operand'; |
| 654 |
$strings['undefined_variable'] = 'undefined variable \'{$error_data}\''; |
| 655 |
$strings['undefined_variable_in_function_definition'] = 'undefined variable \'{$error_data}\' in function definition'; |
| 656 |
$strings['unexpected_closing_bracket'] = 'unexpected closing bracket'; |
| 657 |
$strings['unexpected_comma'] = 'unexpected comma'; |
| 658 |
$strings['unexpected_operator'] = 'unexpected operator \'{$error_data}\''; |
| 659 |
$strings['wrong_number_of_arguments'] = 'wrong number of arguments ({$error_data->given} given, {$error_data->expected} expected)'; |
| 660 |
|
| 661 |
$string = $strings[ $identifier ]; |
| 662 |
|
| 663 |
if ( null !== $error_data ) { |
| 664 |
if ( is_array( $error_data ) ) { |
| 665 |
$search = array(); |
| 666 |
$replace = array(); |
| 667 |
foreach ( $error_data as $key => $value ) { |
| 668 |
if ( is_int( $key ) ) { |
| 669 |
// We do not support numeric keys! |
| 670 |
continue; |
| 671 |
} |
| 672 |
if ( is_object( $value ) || is_array( $value ) ) { |
| 673 |
$value = (array) $value; |
| 674 |
if ( count( $value ) > 1 ) { |
| 675 |
$value = implode( ' or ', $value ); |
| 676 |
} else { |
| 677 |
$value = (string) $value[0]; |
| 678 |
if ( '-1' === $value ) { |
| 679 |
$value = 'at least 1'; |
| 680 |
} |
| 681 |
} |
| 682 |
} |
| 683 |
$search[] = '{$error_data->' . $key . '}'; |
| 684 |
$replace[] = (string) $value; |
| 685 |
} |
| 686 |
if ( $search ) { |
| 687 |
$string = str_replace( $search, $replace, $string ); |
| 688 |
} |
| 689 |
} else { |
| 690 |
$string = str_replace( '{$error_data}', (string) $error_data, $string ); |
| 691 |
} |
| 692 |
} |
| 693 |
|
| 694 |
return $string; |
| 695 |
} |
| 696 |
|
| 697 |
} // class EvalMath |
| 698 |
|
| 699 |
/** |
| 700 |
* Stack for the postfix/infix conversion of math expressions. |
| 701 |
* @package TablePress |
| 702 |
* @subpackage Formulas |
| 703 |
* @since 1.0.0 |
| 704 |
*/ |
| 705 |
class EvalMath_Stack { |
| 706 |
|
| 707 |
/** |
| 708 |
* The stack. |
| 709 |
* |
| 710 |
* @since 1.0.0 |
| 711 |
* @var array |
| 712 |
*/ |
| 713 |
protected $stack = array(); |
| 714 |
|
| 715 |
/** |
| 716 |
* Number of items on the stack. |
| 717 |
* |
| 718 |
* @since 1.0.0 |
| 719 |
* @var int |
| 720 |
*/ |
| 721 |
public $count = 0; |
| 722 |
|
| 723 |
/** |
| 724 |
* Push an item onto the stack. |
| 725 |
* |
| 726 |
* @since 1.0.0 |
| 727 |
* |
| 728 |
* @param mixed $value The item that is pushed onto the stack. |
| 729 |
*/ |
| 730 |
public function push( $value ) { |
| 731 |
$this->stack[ $this->count ] = $value; |
| 732 |
$this->count++; |
| 733 |
} |
| 734 |
|
| 735 |
/** |
| 736 |
* Pop an item from the top of the stack. |
| 737 |
* |
| 738 |
* @since 1.0.0 |
| 739 |
* |
| 740 |
* @return mixed The item that is popped from the stack. |
| 741 |
*/ |
| 742 |
public function pop() { |
| 743 |
if ( $this->count > 0 ) { |
| 744 |
$this->count--; |
| 745 |
return $this->stack[ $this->count ]; |
| 746 |
} |
| 747 |
return null; |
| 748 |
} |
| 749 |
|
| 750 |
/** |
| 751 |
* Pop an item from the end of the stack. |
| 752 |
* |
| 753 |
* @since 1.0.0 |
| 754 |
* |
| 755 |
* @param int $n Count from the end of the stack. |
| 756 |
* @return mixed The item that is popped from the stack. |
| 757 |
*/ |
| 758 |
public function last( $n = 1 ) { |
| 759 |
if ( ( $this->count - $n ) >= 0 ) { |
| 760 |
return $this->stack[ $this->count - $n ]; |
| 761 |
} |
| 762 |
return null; |
| 763 |
} |
| 764 |
|
| 765 |
} // class EvalMath_Stack |
| 766 |
|
| 767 |
/** |
| 768 |
* Common math functions, prepared for usage in EvalMath. |
| 769 |
* @package TablePress |
| 770 |
* @subpackage EvalMath |
| 771 |
* @since 1.0.0 |
| 772 |
*/ |
| 773 |
class EvalMath_Functions { |
| 774 |
|
| 775 |
/** |
| 776 |
* Seed for the generation of random numbers. |
| 777 |
* |
| 778 |
* @since 1.0.0 |
| 779 |
* @var string |
| 780 |
*/ |
| 781 |
protected static $random_seed = null; |
| 782 |
|
| 783 |
/** |
| 784 |
* Choose from two values based on an if-condition. |
| 785 |
* |
| 786 |
* "if" is not a valid function name, which is why it's prefixed with "func_". |
| 787 |
* |
| 788 |
* @since 1.0.0 |
| 789 |
* |
| 790 |
* @param double|int $condition Condition. |
| 791 |
* @param double|int $then Return value if the condition is true. |
| 792 |
* @param double|int $else Return value if the condition is false. |
| 793 |
* @return double|int Result of the if check. |
| 794 |
*/ |
| 795 |
public static function func_if( $condition, $then, $else ) { |
| 796 |
return ( (bool) $condition ? $then : $else ); |
| 797 |
} |
| 798 |
|
| 799 |
/** |
| 800 |
* Return the negation (boolean "not") of a value. |
| 801 |
* |
| 802 |
* Similar to "func_if", the function name is prefixed with "func_", although it wouldn't be necessary. |
| 803 |
* |
| 804 |
* @since 1.0.0 |
| 805 |
* |
| 806 |
* @param double|int $value Value to be negated. |
| 807 |
* @return int Negated value (0 for false, 1 for true). |
| 808 |
*/ |
| 809 |
public static function func_not( $value ) { |
| 810 |
return (int) ! (bool) $value; |
| 811 |
} |
| 812 |
|
| 813 |
/** |
| 814 |
* Calculate the conjunction (boolean "and") of some values. |
| 815 |
* |
| 816 |
* "and" is not a valid function name, which is why it's prefixed with "func_". |
| 817 |
* |
| 818 |
* @since 1.0.0 |
| 819 |
* |
| 820 |
* @param double|int $args Values for which the conjunction shall be calculated. |
| 821 |
* @return int Conjunction of the passed arguments. |
| 822 |
*/ |
| 823 |
public static function func_and( $args ) { |
| 824 |
$args = func_get_args(); |
| 825 |
foreach ( $args as $value ) { |
| 826 |
if ( ! $value ) { |
| 827 |
return 0; |
| 828 |
} |
| 829 |
} |
| 830 |
return 1; |
| 831 |
} |
| 832 |
|
| 833 |
/** |
| 834 |
* Calculate the disjunction (boolean "or") of some values. |
| 835 |
* |
| 836 |
* "or" is not a valid function name, which is why it's prefixed with "func_". |
| 837 |
* |
| 838 |
* @since 1.0.0 |
| 839 |
* |
| 840 |
* @param double|int $args Values for which the disjunction shall be calculated. |
| 841 |
* @return int Disjunction of the passed arguments. |
| 842 |
*/ |
| 843 |
public static function func_or( $args ) { |
| 844 |
$args = func_get_args(); |
| 845 |
foreach ( $args as $value ) { |
| 846 |
if ( $value ) { |
| 847 |
return 1; |
| 848 |
} |
| 849 |
} |
| 850 |
return 0; |
| 851 |
} |
| 852 |
|
| 853 |
/** |
| 854 |
* Return the (rounded) value of Pi. |
| 855 |
* |
| 856 |
* @since 1.0.0 |
| 857 |
* |
| 858 |
* @return double Rounded value of Pi. |
| 859 |
*/ |
| 860 |
public static function pi() { |
| 861 |
return pi(); |
| 862 |
} |
| 863 |
|
| 864 |
/** |
| 865 |
* Calculate the sum of the arguments. |
| 866 |
* |
| 867 |
* @since 1.0.0 |
| 868 |
* |
| 869 |
* @param double|int $args Values for which the sum shall be calculated. |
| 870 |
* @return double|int Sum of the passed arguments. |
| 871 |
*/ |
| 872 |
public static function sum( $args ) { |
| 873 |
$args = func_get_args(); |
| 874 |
return array_sum( $args ); |
| 875 |
} |
| 876 |
|
| 877 |
/** |
| 878 |
* Calculate the product of the arguments. |
| 879 |
* |
| 880 |
* @since 1.0.0 |
| 881 |
* |
| 882 |
* @param double|int $args Values for which the product shall be calculated. |
| 883 |
* @return double|int Product of the passed arguments. |
| 884 |
*/ |
| 885 |
public static function product( $args ) { |
| 886 |
$args = func_get_args(); |
| 887 |
return array_product( $args ); |
| 888 |
} |
| 889 |
|
| 890 |
/** |
| 891 |
* Calculate the average/mean value of the arguments. |
| 892 |
* |
| 893 |
* @since 1.0.0 |
| 894 |
* |
| 895 |
* @param double|int $args Values for which the average shall be calculated. |
| 896 |
* @return double|int Average value of the passed arguments. |
| 897 |
*/ |
| 898 |
public static function average( $args ) { |
| 899 |
$args = func_get_args(); |
| 900 |
return ( call_user_func_array( array( 'self', 'sum' ), $args ) / count( $args ) ); |
| 901 |
} |
| 902 |
|
| 903 |
/** |
| 904 |
* Calculate the median of the arguments. |
| 905 |
* |
| 906 |
* For even counts of arguments, the upper median is returned. |
| 907 |
* |
| 908 |
* @since 1.0.0 |
| 909 |
* |
| 910 |
* @param double|int $args Values for which the median shall be calculated. |
| 911 |
* @return double|int Median of the passed arguments. |
| 912 |
*/ |
| 913 |
public static function median( $args ) { |
| 914 |
$args = func_get_args(); |
| 915 |
sort( $args ); |
| 916 |
$middle = floor( count( $args ) / 2 ); // Upper median for even counts. |
| 917 |
return $args[ $middle ]; |
| 918 |
} |
| 919 |
|
| 920 |
/** |
| 921 |
* Calculate the mode of the arguments. |
| 922 |
* |
| 923 |
* @since 1.0.0 |
| 924 |
* |
| 925 |
* @param double|int $args Values for which the mode shall be calculated. |
| 926 |
* @return double|int Mode of the passed arguments. |
| 927 |
*/ |
| 928 |
public static function mode( $args ) { |
| 929 |
$args = func_get_args(); |
| 930 |
$values = array_count_values( $args ); |
| 931 |
asort( $values ); |
| 932 |
end( $values ); |
| 933 |
return key( $values ); |
| 934 |
} |
| 935 |
|
| 936 |
/** |
| 937 |
* Calculate the range of the arguments. |
| 938 |
* |
| 939 |
* @since 1.0.0 |
| 940 |
* |
| 941 |
* @param double|int $args Values for which the range shall be calculated. |
| 942 |
* @return double|int Range of the passed arguments. |
| 943 |
*/ |
| 944 |
public static function range( $args ) { |
| 945 |
$args = func_get_args(); |
| 946 |
sort( $args ); |
| 947 |
return end( $args ) - reset( $args ); |
| 948 |
} |
| 949 |
|
| 950 |
/** |
| 951 |
* Find the maximum value of the arguments. |
| 952 |
* |
| 953 |
* @since 1.0.0 |
| 954 |
* |
| 955 |
* @param double|int $args Values for which the maximum value shall be found. |
| 956 |
* @return double|int Maximum value of the passed arguments. |
| 957 |
*/ |
| 958 |
public static function max( $args ) { |
| 959 |
$args = func_get_args(); |
| 960 |
return max( $args ); |
| 961 |
} |
| 962 |
|
| 963 |
/** |
| 964 |
* Find the minimum value of the arguments. |
| 965 |
* |
| 966 |
* @since 1.0.0 |
| 967 |
* |
| 968 |
* @param double|int $args Values for which the minimum value shall be found. |
| 969 |
* @return double|int Minimum value of the passed arguments. |
| 970 |
*/ |
| 971 |
public static function min( $args ) { |
| 972 |
$args = func_get_args(); |
| 973 |
return min( $args ); |
| 974 |
} |
| 975 |
|
| 976 |
/** |
| 977 |
* Calculate the remainder of a division of two numbers. |
| 978 |
* |
| 979 |
* @since 1.0.0 |
| 980 |
* |
| 981 |
* @param double|int $op1 First number (dividend). |
| 982 |
* @param double|int $op2 Second number (divisor). |
| 983 |
* @return double|int Remainer of the division (dividend / divisor). |
| 984 |
*/ |
| 985 |
public static function mod( $op1, $op2 ) { |
| 986 |
return $op1 % $op2; |
| 987 |
} |
| 988 |
|
| 989 |
/** |
| 990 |
* Calculate the power of a base and an exponent. |
| 991 |
* |
| 992 |
* @since 1.0.0 |
| 993 |
* |
| 994 |
* @param double|int $base Base. |
| 995 |
* @param double|int $exponent Exponent. |
| 996 |
* @return double|int Power base^exponent. |
| 997 |
*/ |
| 998 |
public static function power( $base, $exponent ) { |
| 999 |
return pow( $base, $exponent ); |
| 1000 |
} |
| 1001 |
|
| 1002 |
/** |
| 1003 |
* Calculate the logarithm of a number to a base. |
| 1004 |
* |
| 1005 |
* @since 1.0.0 |
| 1006 |
* |
| 1007 |
* @param double|int $number Number. |
| 1008 |
* @param double|int $base Optional. Base for the logarithm. Default e (for the natural logarithm). |
| 1009 |
* @return double Logarithm of the number to the base. |
| 1010 |
*/ |
| 1011 |
public static function log( $number, $base = M_E ) { |
| 1012 |
return log( $number, $base ); |
| 1013 |
} |
| 1014 |
|
| 1015 |
/** |
| 1016 |
* Calculate the arc tangent of two variables. |
| 1017 |
* |
| 1018 |
* The signs of the numbers determine the quadrant of the result. |
| 1019 |
* |
| 1020 |
* @since 1.0.0 |
| 1021 |
* |
| 1022 |
* @param double|int $op1 First number. |
| 1023 |
* @param double|int $op2 Second number. |
| 1024 |
* @return double Arc tangent of two numbers, similar to arc tangent of $op1/op$ except for the sign. |
| 1025 |
*/ |
| 1026 |
public static function atan2( $op1, $op2 ) { |
| 1027 |
return atan2( $op1, $op2 ); |
| 1028 |
} |
| 1029 |
|
| 1030 |
/** |
| 1031 |
* Round a number to a given precision. |
| 1032 |
* |
| 1033 |
* @since 1.0.0 |
| 1034 |
* |
| 1035 |
* @param double|int $value Number to be rounded. |
| 1036 |
* @param double|int $decimals Optional. Number of decimals after the comma after the rounding. |
| 1037 |
* @return double Rounded number. |
| 1038 |
*/ |
| 1039 |
public static function round( $value, $decimals = 0 ) { |
| 1040 |
return round( $value, $decimals ); |
| 1041 |
} |
| 1042 |
|
| 1043 |
/** |
| 1044 |
* Format a number with the . as the decimal separator and the , as the thousand separator, rounded to a precision. |
| 1045 |
* |
| 1046 |
* The is the common number format in English-language regions. |
| 1047 |
* |
| 1048 |
* @since 1.0.0 |
| 1049 |
* |
| 1050 |
* @param double|int $value Number to be rounded and formatted. |
| 1051 |
* @param double|int $decimals Optional. Number of decimals after the decimal separator after the rounding. |
| 1052 |
* @return double Formatted number. |
| 1053 |
*/ |
| 1054 |
public static function number_format( $value, $decimals = 0 ) { |
| 1055 |
return number_format( $value, $decimals, '.', ',' ); |
| 1056 |
} |
| 1057 |
|
| 1058 |
/** |
| 1059 |
* Format a number with the , as the decimal separator and the space as the thousand separator, rounded to a precision. |
| 1060 |
* |
| 1061 |
* The is the common number format in non-English-language regions, mainly in Europe. |
| 1062 |
* |
| 1063 |
* @since 1.0.0 |
| 1064 |
* |
| 1065 |
* @param double|int $value Number to be rounded and formatted. |
| 1066 |
* @param double|int $decimals Optional. Number of decimals after the decimal separator after the rounding. |
| 1067 |
* @return double Formatted number. |
| 1068 |
*/ |
| 1069 |
public static function number_format_eu( $value, $decimals = 0 ) { |
| 1070 |
return number_format( $value, $decimals, ',', ' ' ); |
| 1071 |
} |
| 1072 |
|
| 1073 |
/** |
| 1074 |
* Set the seed for the generation of random numbers. |
| 1075 |
* |
| 1076 |
* @since 1.0.0 |
| 1077 |
* |
| 1078 |
* @param string The seed. |
| 1079 |
*/ |
| 1080 |
protected static function _set_random_seed( $random_seed ) { |
| 1081 |
self::$random_seed = $random_seed; |
| 1082 |
} |
| 1083 |
|
| 1084 |
/** |
| 1085 |
* Get the seed for the generation of random numbers. |
| 1086 |
* |
| 1087 |
* @since 1.0.0 |
| 1088 |
* |
| 1089 |
* @return string The seed. |
| 1090 |
*/ |
| 1091 |
protected static function _get_random_seed() { |
| 1092 |
if ( is_null( self::$random_seed ) ) { |
| 1093 |
return microtime(); |
| 1094 |
} else { |
| 1095 |
return self::$random_seed; |
| 1096 |
} |
| 1097 |
} |
| 1098 |
|
| 1099 |
/** |
| 1100 |
* Get a random integer from a range. |
| 1101 |
* |
| 1102 |
* @since 1.0.0 |
| 1103 |
* |
| 1104 |
* @param int $min Minimum value for the range. |
| 1105 |
* @param int $max Maximum value for the range. |
| 1106 |
* @return int Random integer from the range [$min, $max]. |
| 1107 |
*/ |
| 1108 |
public static function rand_int( $min, $max ) { |
| 1109 |
// Swap min and max value if min is bigger than max. |
| 1110 |
if ( $min > $max ) { |
| 1111 |
$tmp = $max; |
| 1112 |
$max = $min; |
| 1113 |
$min = $tmp; |
| 1114 |
unset( $tmp ); |
| 1115 |
} |
| 1116 |
$number_characters = ceil( log( $max + 1 - $min, '16' ) ); |
| 1117 |
$md5string = md5( self::_get_random_seed() ); |
| 1118 |
$offset = 0; |
| 1119 |
do { |
| 1120 |
while ( ( $offset + $number_characters ) > strlen( $md5string ) ) { |
| 1121 |
$md5string .= md5( $md5string ); |
| 1122 |
} |
| 1123 |
$randomno = hexdec( substr( $md5string, $offset, $number_characters ) ); |
| 1124 |
$offset += $number_characters; |
| 1125 |
} while ( ( $min + $randomno ) > $max ); |
| 1126 |
return $min + $randomno; |
| 1127 |
} |
| 1128 |
|
| 1129 |
/** |
| 1130 |
* Get a random double value from a range [0, 1]. |
| 1131 |
* |
| 1132 |
* @since 1.0.0 |
| 1133 |
* |
| 1134 |
* @return double Random number from the range [0, 1]. |
| 1135 |
*/ |
| 1136 |
public static function rand_float() { |
| 1137 |
$random_values = unpack( 'v', md5( self::_get_random_seed(), true ) ); |
| 1138 |
return array_shift( $random_values ) / 65536; |
| 1139 |
} |
| 1140 |
|
| 1141 |
} // class EvalMath_Functions |
| 1142 |
|
