Context.php

<?php
namespace duzun\hQuery;

// ------------------------------------------------------------------------
class_exists('duzun\\hQuery\\Node', false) or require_once __DIR__ . DIRECTORY_SEPARATOR . 'Node.php';

// ------------------------------------------------------------------------
class Context extends Node {

    public function __construct($doc=NULL, $el_arr=NULL) {
        if($el_arr instanceof parent) {
           if(!$doc) $doc = $el_arr->doc();
           $el_arr = $el_arr->ids;
        }
        elseif(is_array($el_arr)) {
            ksort($el_arr);
        }
        parent::__construct($doc, $el_arr, true);
    }

    public function intersect($el, $eq=true) {
        if($el instanceof self) {
            if($el === $this) {
                if($eq) return $this;
                else $el = array();
            }
            else {
                $el = $el->ids;
            }
        }
        else {
            $el = $this->_ctx_ids($this->_doc_ids($el, true));
        }
        foreach($el as $b => $e) {
            if(!$this->_has($b, $eq)) unset($el[$b]);
        }

        return new self($el, $this->doc);
    }
}