String alternative of constants?

[jehoshua02]

<?php

$distance = new \Reusables\Distance(12, 'inches');
$distance = new \Reusables\Distance(1, 'inch');
$distance = new \Reusables\Distance(12, Distance::INCHES);

[jehoshua02]

I think this would just require a mapping from strings to constants. Constants will all be in plural all caps.

<?php

class Distance {
  protected static $units = array(
    'inches' => self::INCHES,
    'inch' => self::INCHES
  );
}

This probably involves some strtolower before looking up the constant.

[jehoshua02]

Or ... the mapping keys can be uppercase and we do strtoupper. That way we can even use constants for the keys and have a single mapping array for singular/plural lookups too.