<?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\CustomFunction;
use NXP\Classes\Operator;
use NXP\Classes\Token;
use NXP\Classes\Tokenizer;
use NXP\Exception\DivisionByZeroException;
use NXP\Exception\IncorrectNumberOfFunctionParametersException;
use NXP\Exception\MathExecutorException;
use NXP\Exception\UnknownVariableException;
use ReflectionException;
/**
* Class MathExecutor
* @package NXP
*/
class MathExecutor
{
/**
* Available variables
*
* @var array<string, float|string>
*/
protected array $variables = [];
/**
* @var callable|null
*/
protected $onVarNotFound = null;
/**
* @var callable|null
*/
protected $onVarValidation = null;
/**
* @var Operator[]
*/
protected array $operators = [];
/**
* @var array<string, CustomFunction>
*/
protected array $functions = [];
/**
* @var array<string, Token[]>
*/
protected array $cache = [];
/**
* Base math operators
*/
public function __construct()
{
$this->addDefaults();
}
public function __clone()
{
$this->addDefaults();
}
/**
* Add operator to executor
*
* @return MathExecutor
*/
public function addOperator(Operator $operator) : self
{
$this->operators[$operator->operator] = $operator;
return $this;
}
/**
* Execute expression
*
* @throws Exception\IncorrectBracketsException
* @throws Exception\IncorrectExpressionException
* @throws Exception\UnknownOperatorException
* @throws UnknownVariableException
* @return int|float|string|null
*/
public function execute(string $expression, bool $cache = true)
{
$cacheKey = $expression;
if (! \array_key_exists($cacheKey, $this->cache)) {
$tokens = (new Tokenizer($expression, $this->operators))->tokenize()->buildReversePolishNotation();
if ($cache) {
$this->cache[$cacheKey] = $tokens;
}
} else {
$tokens = $this->cache[$cacheKey];
}
$calculator = new Calculator($this->functions, $this->operators);
return $calculator->calculate($tokens, $this->variables, $this->onVarNotFound);
}
/**
* Add function to executor
*
* @param string $name Name of function
* @param callable|null $function Function
*
* @throws ReflectionException
* @throws Exception\IncorrectNumberOfFunctionParametersException
* @return MathExecutor
*/
public function addFunction(string $name, ?callable $function = null) : self
{
$this->functions[$name] = new CustomFunction($name, $function);
return $this;
}
/**
* Get all vars
*
* @return array<string, float|string>
*/
public function getVars() : array
{
return $this->variables;
}
/**
* Get a specific var
*
* @throws UnknownVariableException if VarNotFoundHandler is not set
* @return int|float
*/
public function getVar(string $variable)
{
if (! \array_key_exists($variable, $this->variables)) {
if ($this->onVarNotFound) {
return \call_user_func($this->onVarNotFound, $variable);
}
throw new UnknownVariableException("Variable ({$variable}) not set");
}
return $this->variables[$variable];
}
/**
* Add variable to executor. To set a custom validator use setVarValidationHandler.
*
* @throws MathExecutorException if the value is invalid based on the default or custom validator
* @return MathExecutor
*/
public function setVar(string $variable, $value) : self
{
if ($this->onVarValidation) {
\call_user_func($this->onVarValidation, $variable, $value);
}
$this->variables[$variable] = $value;
return $this;
}
/**
* Test to see if a variable exists
*
*/
public function varExists(string $variable) : bool
{
return \array_key_exists($variable, $this->variables);
}
/**
* Add variables to executor
*
* @param array<string, float|int|string> $variables
* @param bool $clear Clear previous variables
* @throws \Exception
* @return MathExecutor
*/
public function setVars(array $variables, bool $clear = true) : self
{
if ($clear) {
$this->removeVars();
}
foreach ($variables as $name => $value) {
$this->setVar($name, $value);
}
return $this;
}
/**
* Define a method that will be invoked when a variable is not found.
* The first parameter will be the variable name, and the returned value will be used as the variable value.
*
*
* @return MathExecutor
*/
public function setVarNotFoundHandler(callable $handler) : self
{
$this->onVarNotFound = $handler;
return $this;
}
/**
* Define a validation method that will be invoked when a variable is set using setVar.
* The first parameter will be the variable name, and the second will be the variable value.
* Set to null to disable validation.
*
* @param ?callable $handler throws a MathExecutorException in case of an invalid variable
*
* @return MathExecutor
*/
public function setVarValidationHandler(?callable $handler) : self
{
$this->onVarValidation = $handler;
return $this;
}
/**
* Remove variable from executor
*
* @return MathExecutor
*/
public function removeVar(string $variable) : self
{
unset($this->variables[$variable]);
return $this;
}
/**
* Remove all variables and the variable not found handler
* @return MathExecutor
*/
public function removeVars() : self
{
$this->variables = [];
$this->onVarNotFound = null;
return $this;
}
/**
* Get all registered operators to executor
*
* @return array<Operator> of operator class names
*/
public function getOperators()
{
return $this->operators;
}
/**
* Get all registered functions
*
* @return array<string, CustomFunction> containing callback and places indexed by
* function name
*/
public function getFunctions() : array
{
return $this->functions;
}
/**
* Set division by zero returns zero instead of throwing DivisionByZeroException
*/
public function setDivisionByZeroIsZero() : self
{
$this->addOperator(new Operator('/', false, 180, static fn($a, $b) => 0 == $b ? 0 : $a / $b));
return $this;
}
/**
* Get cache array with tokens
* @return array<string, Token[]>
*/
public function getCache() : array
{
return $this->cache;
}
/**
* Clear token's cache
*/
public function clearCache() : void
{
$this->cache = [];
}
/**
* Set default operands and functions
* @throws ReflectionException
*/
protected function addDefaults() : void
{
foreach ($this->defaultOperators() as $name => $operator) {
[$callable, $priority, $isRightAssoc] = $operator;
$this->addOperator(new Operator($name, $isRightAssoc, $priority, $callable));
}
foreach ($this->defaultFunctions() as $name => $callable) {
$this->addFunction($name, $callable);
}
$this->onVarValidation = [$this, 'defaultVarValidation'];
$this->variables = $this->defaultVars();
}
/**
* Get the default operators
*
* @return array<string, array{callable, int, bool}>
*/
protected function defaultOperators() : array
{
return [
'+' => [static fn($a, $b) => $a + $b, 170, false],
'-' => [static fn($a, $b) => $a - $b, 170, false],
// unary positive token
'uPos' => [static fn($a) => $a, 200, false],
// unary minus token
'uNeg' => [static fn($a) => 0 - $a, 200, false],
'*' => [static fn($a, $b) => $a * $b, 180, false],
'/' => [
static function($a, $b) { /** @todo PHP8: Use throw as expression -> static fn($a, $b) => 0 == $b ? throw new DivisionByZeroException() : $a / $b */
if (0 == $b) {
throw new DivisionByZeroException();
}
return $a / $b;
},
180,
false
],
'^' => [static fn($a, $b) => \pow($a, $b), 220, true],
'&&' => [static fn($a, $b) => $a && $b, 100, false],
'||' => [static fn($a, $b) => $a || $b, 90, false],
'==' => [static fn($a, $b) => \is_string($a) || \is_string($b) ? 0 == \strcmp($a, $b) : $a == $b, 140, false],
'!=' => [static fn($a, $b) => \is_string($a) || \is_string($b) ? 0 != \strcmp($a, $b) : $a != $b, 140, false],
'>=' => [static fn($a, $b) => $a >= $b, 150, false],
'>' => [static fn($a, $b) => $a > $b, 150, false],
'<=' => [static fn($a, $b) => $a <= $b, 150, false],
'<' => [static fn($a, $b) => $a < $b, 150, false],
];
}
/**
* Gets the default functions as an array. Key is function name
* and value is the function as a closure.
*
* @return array<callable>
*/
protected function defaultFunctions() : array
{
return [
'abs' => static fn($arg) => \abs($arg),
'acos' => static fn($arg) => \acos($arg),
'acosh' => static fn($arg) => \acosh($arg),
'arcsin' => static fn($arg) => \asin($arg),
'arcctg' => static fn($arg) => M_PI / 2 - \atan($arg),
'arccot' => static fn($arg) => M_PI / 2 - \atan($arg),
'arccotan' => static fn($arg) => M_PI / 2 - \atan($arg),
'arcsec' => static fn($arg) => \acos(1 / $arg),
'arccosec' => static fn($arg) => \asin(1 / $arg),
'arccsc' => static fn($arg) => \asin(1 / $arg),
'arccos' => static fn($arg) => \acos($arg),
'arctan' => static fn($arg) => \atan($arg),
'arctg' => static fn($arg) => \atan($arg),
'asin' => static fn($arg) => \asin($arg),
'atan' => static fn($arg) => \atan($arg),
'atan2' => static fn($arg1, $arg2) => \atan2($arg1, $arg2),
'atanh' => static fn($arg) => \atanh($arg),
'atn' => static fn($arg) => \atan($arg),
'avg' => static function($arg1, $args) {
if (\is_array($arg1)){
return \array_sum($arg1) / \count($arg1);
}
if (0 === \count($args)){
throw new IncorrectNumberOfFunctionParametersException();
}
$args = [$arg1, ...$args];
return \array_sum($args) / \count($args);
},
'bindec' => static fn($arg) => \bindec($arg),
'ceil' => static fn($arg) => \ceil($arg),
'cos' => static fn($arg) => \cos($arg),
'cosec' => static fn($arg) => 1 / \sin($arg),
'csc' => static fn($arg) => 1 / \sin($arg),
'cosh' => static fn($arg) => \cosh($arg),
'ctg' => static fn($arg) => \cos($arg) / \sin($arg),
'cot' => static fn($arg) => \cos($arg) / \sin($arg),
'cotan' => static fn($arg) => \cos($arg) / \sin($arg),
'cotg' => static fn($arg) => \cos($arg) / \sin($arg),
'ctn' => static fn($arg) => \cos($arg) / \sin($arg),
'decbin' => static fn($arg) => \decbin($arg),
'dechex' => static fn($arg) => \dechex($arg),
'decoct' => static fn($arg) => \decoct($arg),
'deg2rad' => static fn($arg) => \deg2rad($arg),
'exp' => static fn($arg) => \exp($arg),
'expm1' => static fn($arg) => \expm1($arg),
'floor' => static fn($arg) => \floor($arg),
'fmod' => static fn($arg1, $arg2) => \fmod($arg1, $arg2),
'hexdec' => static fn($arg) => \hexdec($arg),
'hypot' => static fn($arg1, $arg2) => \hypot($arg1, $arg2),
'if' => function($expr, $trueval, $falseval) {
if (true === $expr || false === $expr) {
$exres = $expr;
} else {
$exres = $this->execute($expr);
}
if ($exres) {
return $this->execute($trueval);
}
return $this->execute($falseval);
},
'intdiv' => static fn($arg1, $arg2) => \intdiv($arg1, $arg2),
'ln' => static fn($arg) => \log($arg),
'lg' => static fn($arg) => \log10($arg),
'log' => static fn($arg) => \log($arg),
'log10' => static fn($arg) => \log10($arg),
'log1p' => static fn($arg) => \log1p($arg),
'max' => static function($arg1, ...$args) {
if (! \is_array($arg1) && 0 === \count($args)){
throw new IncorrectNumberOfFunctionParametersException();
}
return \max($arg1, ...$args);
},
'min' => static function($arg1, ...$args) {
if (! \is_array($arg1) && 0 === \count($args)){
throw new IncorrectNumberOfFunctionParametersException();
}
return \min($arg1, ...$args);
},
'octdec' => static fn($arg) => \octdec($arg),
'pi' => static fn() => M_PI,
'pow' => static fn($arg1, $arg2) => $arg1 ** $arg2,
'rad2deg' => static fn($arg) => \rad2deg($arg),
'round' => static fn($num, int $precision = 0) => \round($num, $precision),
'sin' => static fn($arg) => \sin($arg),
'sinh' => static fn($arg) => \sinh($arg),
'sec' => static fn($arg) => 1 / \cos($arg),
'sqrt' => static fn($arg) => \sqrt($arg),
'tan' => static fn($arg) => \tan($arg),
'tanh' => static fn($arg) => \tanh($arg),
'tn' => static fn($arg) => \tan($arg),
'tg' => static fn($arg) => \tan($arg)
];
}
/**
* Returns the default variables names as key/value pairs
*
* @return array<string, float>
*/
protected function defaultVars() : array
{
return [
'pi' => 3.14159265359,
'e' => 2.71828182846
];
}
/**
* Default variable validation, ensures that the value is a scalar.
* @throws MathExecutorException if the value is not a scalar
*/
protected function defaultVarValidation(string $variable, $value) : void
{
if (! \is_scalar($value) && ! \is_array($value) && null !== $value) {
$type = \gettype($value);
throw new MathExecutorException("Variable ({$variable}) type ({$type}) is not scalar or array!");
}
}
}
