class RuleSetIterator

class RuleSetIterator implements \Iterator {
    
    /** @var array<RuleSet::TYPE_*, Rule[]> */
    protected $rules;
    
    /** @var array<RuleSet::TYPE_*> */
    protected $types;
    
    /** @var int */
    protected $currentOffset;
    
    /** @var RuleSet::TYPE_*|-1 */
    protected $currentType;
    
    /** @var int */
    protected $currentTypeOffset;
    
    /**
     * @param array<RuleSet::TYPE_*, Rule[]> $rules
     */
    public function __construct(array $rules) {
        $this->rules = $rules;
        $this->types = array_keys($rules);
        sort($this->types);
        $this->rewind();
    }
    public function current() : Rule {
        return $this->rules[$this->currentType][$this->currentOffset];
    }
    
    /**
     * @return RuleSet::TYPE_*|-1
     */
    public function key() : int {
        return $this->currentType;
    }
    public function next() : void {
        $this->currentOffset++;
        if (!isset($this->rules[$this->currentType])) {
            return;
        }
        if ($this->currentOffset >= \count($this->rules[$this->currentType])) {
            $this->currentOffset = 0;
            do {
                $this->currentTypeOffset++;
                if (!isset($this->types[$this->currentTypeOffset])) {
                    $this->currentType = -1;
                    break;
                }
                $this->currentType = $this->types[$this->currentTypeOffset];
            } while (0 === \count($this->rules[$this->currentType]));
        }
    }
    public function rewind() : void {
        $this->currentOffset = 0;
        $this->currentTypeOffset = -1;
        $this->currentType = -1;
        do {
            $this->currentTypeOffset++;
            if (!isset($this->types[$this->currentTypeOffset])) {
                $this->currentType = -1;
                break;
            }
            $this->currentType = $this->types[$this->currentTypeOffset];
        } while (0 === \count($this->rules[$this->currentType]));
    }
    public function valid() : bool {
        return isset($this->rules[$this->currentType], $this->rules[$this->currentType][$this->currentOffset]);
    }

}