Comparable

Interface to implement custom comparison logic for classes instead of writing them inline over and over again., _(*2)

Provided is the interface itself that establishes the contract that implementing classes have to have the compare method. Furthermore a specific exception is provided that can be used to notify callers that a comparison of the passed value is not possible. Last but not least a dummy class that can be used in tests as a substitute for doubles, stubs, or mocks is included as well., _(*3)

Installation

Open a terminal, enter your project directory and execute the following command to add this package to your dependencies:, _(*4)

$ composer require fleshgrinder/comparable

This command requires you to have Composer installed globally, as explained in the installation chapter of the Composer documentation., _(*5)

Usage

Simply implement the interface and the required compareTo method., _(*6)

class YourClass implements Comparable {

    const TOLERANCE = 0.0001;

    protected $value;

    public function __construct($value) {
        $this->value = (float) $value;
    }

    /**
     * @inheritDoc
     */
    public function compareTo($other) {
        if (($other instanceof $this) === false) {
            throw new UncomparableException();
        }

        $diff = $other->value() - $this->value;

        if ($diff > static::TOLERANCE) {
            return 1;
        }

        if ($diff < -static::TOLERANCE) {
            return -1;
        }

        return 0;
    }

}