MathExecutor/README.md

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')");