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<?php
/**
* This file is part of the MathExecutor package
*
* (c) Alexander Kiryukhin
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code
*/
namespace NXP;
use NXP\Classes\Calculator;
use NXP\Classes\Lexer;
use NXP\Classes\Token;
use NXP\Classes\TokenFactory;
/**
* Class MathExecutor
* @package NXP
*/
class MathExecutor
{
/**
* Available variables
*
* @var array
*/
private $variables = array();
/**
* @var TokenFactory
*/
private $tokenFactory;
/**
* @var array
*/
private $cache = array();
/**
* Base math operators
*/
public function __construct()
{
$this->addDefaults();
}
public function __clone()
{
$this->addDefaults();
}
/**
* Set default operands and functions
*/
protected function addDefaults()
{
$this->tokenFactory = new TokenFactory();
$this->tokenFactory->addOperator('NXP\Classes\Token\TokenPlus');
$this->tokenFactory->addOperator('NXP\Classes\Token\TokenMinus');
$this->tokenFactory->addOperator('NXP\Classes\Token\TokenMultiply');
$this->tokenFactory->addOperator('NXP\Classes\Token\TokenDivision');
$this->tokenFactory->addOperator('NXP\Classes\Token\TokenDegree');
$this->tokenFactory->addFunction('sin', 'sin');
$this->tokenFactory->addFunction('cos', 'cos');
$this->tokenFactory->addFunction('tn', 'tan');
$this->tokenFactory->addFunction('asin', 'asin');
$this->tokenFactory->addFunction('acos', 'acos');
$this->tokenFactory->addFunction('atn', 'atan');
$this->tokenFactory->addFunction('min', 'min', 2);
$this->tokenFactory->addFunction('max', 'max', 2);
$this->tokenFactory->addFunction('avg', function($arg1, $arg2) { return ($arg1 + $arg2) / 2; }, 2);
$this->setVars(array(
'pi' => 3.14159265359,
'e' => 2.71828182846
));
}
/**
* Add variable to executor
*
* @param string $variable
* @param integer|float $value
* @throws \Exception
* @return MathExecutor
*/
public function setVar($variable, $value)
{
$this->variables[$variable] = $value;
return $this;
}
/**
* Add variables to executor
*
* @param array $variables
* @param bool $clear Clear previous variables
* @return MathExecutor
*/
public function setVars(array $variables, $clear = true)
{
if ($clear) {
$this->removeVars();
}
foreach ($variables as $name => $value) {
$this->setVar($name, $value);
}
return $this;
}
/**
* Remove variable from executor
*
* @param string $variable
* @return MathExecutor
*/
public function removeVar($variable)
{
unset ($this->variables[$variable]);
return $this;
}
/**
* Remove all variables
*/
public function removeVars()
{
$this->variables = array();
return $this;
}
/**
* Add operator to executor
*
* @param string $operatorClass Class of operator token
* @return MathExecutor
*/
public function addOperator($operatorClass)
{
$this->tokenFactory->addOperator($operatorClass);
return $this;
}
/**
* Get all registered operators to executor
*
* @return array of operator class names
*/
public function getOperators()
{
return $this->tokenFactory->getOperators();
}
/**
* Add function to executor
*
* @param string $name Name of function
* @param callable $function Function
* @param int $places Count of arguments
* @return MathExecutor
*/
public function addFunction($name, $function = null, $places = 1)
{
$this->tokenFactory->addFunction($name, $function, $places);
return $this;
}
/**
* Get all registered functions
*
* @return array containing callback and places indexed by
* function name
*/
public function getFunctions()
{
return $this->tokenFactory->getFunctions();
}
/**
* Execute expression
*
* @param $expression
* @return number
*/
public function execute($expression)
{
if (!array_key_exists($expression, $this->cache)) {
$lexer = new Lexer($this->tokenFactory);
$tokensStream = $lexer->stringToTokensStream($expression);
$tokens = $lexer->buildReversePolishNotation($tokensStream);
$this->cache[$expression] = $tokens;
} else {
$tokens = $this->cache[$expression];
}
$calculator = new Calculator();
$result = $calculator->calculate($tokens, $this->variables);
return $result;
}
}
|
