Listing 1536

<?php
/**
 * A class that uses php built-in interface Iterator. 
 * So you can iterat over a string with a foreach loop.
 *
 */
class String extends Element implements Countable, Iterator {
 
    /**
     * Position of the string index
     *
     * @var int
     */
    private $current = 0;
    
    /**
     * True if current position is les then length of the string. Otherwise false.
      *
     * @var boolean
     */
    private $valid = false;
 
    /**
     * Class constructor. Sets string value an length.
     *
     * @param string $html
     */
    function __construct($string) {
        $this->value['string'] = $string;
        $this->value['length'] = strlen($string);
    }
 
    /**
     * Defined by Iterator interface
     *
     */
    public function rewind(){
        $this->current = 0;
        $this->valid = ($this->current < $this->value['length']);
    }
 
    /**
     * Defined by Iterator interface
     *
     */
    public function current(){
        return $this->value['string'][$this->current];
    }
 
    /**
     * Defined by Iterator interface
     *
     * @return string
     */
    public function key(){
        return $this->current;
    }
 
    /**
     * Defined by Iterator interface
     *
     */
    public function next(){
        $this->current++;
        $this->valid = ($this->current < $this->value['length']);
    }
 
    /**
     * Defined by Iterator interface
     *
     * @return boolean
     */
    public function valid(){
        return $this->valid;
    }
 
    /**
     * Defined by Iterator interface
     *
     * @return int
     */
    public function count() {
        return $this->value['length'];
    }
 
    /**
     * Reverse one step.
     *
     */
    public function previous() {
        if (--$this->current < 0) {
            $this->current = 0;
        }
    }
}