<?php
 
class EnumIterator implements Iterator {
	protected $classes = array();
	protected $enum_type;
 
	public function __construct($enum_type) {
		if(!class_exists($enum_type) || !is_subclass_of($enum_type, "Enum")) throw new Exception("Specified Enum type doesn't exist or is not an Enum!");
		$this->enum_type = $enum_type;
		foreach(get_declared_classes() as $class) {
			if(is_subclass_of($class, $this->enum_type)) {
				$this->classes[] = $class;
			}
		}
	}
 
	public function current() {
		return current($this->classes);
	}
 
	public function key() {
		return key($this->classes);
	}
 
	public function next() {
		next($this->classes);
		return $this->current();
	}
 
	public function rewind() {
		return reset($this->classes);
	}
 
	public function valid() {
		return (bool) $this->current();
	}
}