MathExecutor

A simple math expressions calculator

Features:

Built in support for +, -, *, / and power (^) operators plus ()
Support for user defined operators
Support for user defined functions
Unlimited varable name lengths
String support, as function parameters or as evaluated by PHP
Exceptions on divide by zero, or treat as zero
Unary Minus
Pi ($pi) and Euler's number ($e) support to 11 decimal places

Install via Composer:

Stable branch

composer require "nxp/math-executor"

Dev branch (currently unsupported)

composer require "nxp/math-executor" "dev-dev"

Sample usage:

require "vendor/autoload.php";

$executor = new \NXP\MathExecutor();

echo $executor->execute("1 + 2 * (2 - (4+10))^2 + sin(10)");

Functions:

Default functions: * sin * cos * tn * asin * acos * atn * min * max * avg

Add custom function to executor:

$executor->addFunction('abs', function($arg) {
    return abs($arg);
}, 1);

Operators:

Default operators: + - * / ^

Add custom operator to executor:

<?php
namespace MyNamespace;

use NXP\Classes\Token\AbstractOperator;

class ModulusToken extends AbstractOperator
{
    /**
     * Regex of this operator
     * @return string
     */
    public static function getRegex()
    {
        return '\%';
    }

    /**
     * Priority of this operator
     * @return int
     */
    public function getPriority()
    {
        return 3;
    }

    /**
     * Associaion of this operator (self::LEFT_ASSOC or self::RIGHT_ASSOC)
     * @return string
     */
    public function getAssociation()
    {
        return self::LEFT_ASSOC;
    }

    /**
     * Execution of this operator
     * @param InterfaceToken[] $stack Stack of tokens
     * @return TokenNumber            Result of execution
     */
    public function execute(&$stack)
    {
        $op2 = array_pop($stack);
        $op1 = array_pop($stack);
        $result = $op1->getValue() % $op2->getValue();

        return new TokenNumber($result);
    }
}

And adding to executor:

$executor->addOperator('MyNamespace\ModulusToken');

Variables:

Default variables:

$pi = 3.14159265359
$e = 2.71828182846

You can add own variable to executor:

$executor->setVars([
    'var1' => 0.15,
    'var2' => 0.22
]);

echo $executor->execute("$var1 + $var2");

Division By Zero Support:

By default, the result of division by zero is zero and no error is generated. You have the option to thow a \NXP\Exception\DivisionByZeroException by by calling setDivisionByZeroException.

$executor->setDivisionByZeroException();
try {
    echo $executor->execute('1/0');
} catch (\NXP\Exception\DivisionByZeroException $e) {
    echo $e->getMessage();
}

Unary Minus Operator:

Negative numbers are supported via the unary minus operator, but need to have a space before the minus sign. -1+ -3 is legal, while '-1+-3 will produce an error due to the way the parser works. Positive numbers are not explicitly supported as unsigned numbers are assumed positive.

String Support:

Expressions can contain double or single quoted strings that are evaluated the same way as PHP. You can also pass strings to functions.

echo $executor->execute("1 + '2.5' * '.5' + myFunction('category')");