code: function next() {
  		$this->token_start = null;
  
  		if (++$this->pos < $this->size) {
  			if (isset($this->char_map[$this->doc[$this->pos]])) {
  				if (is_string($this->char_map[$this->doc[$this->pos]])) {
  					return ($this->token = $this->{$this->char_map[$this->doc[$this->pos]]}());
  				} else {
  					return ($this->token = $this->char_map[$this->doc[$this->pos]]);
  				}
  			} else {
  				return ($this->token = self::TOK_UNKNOWN);
  			}
  		} else {
  			return ($this->token = self::TOK_NULL);
  		}
  	}
docs: Continues to the next token
  @return int Next token ({@link TOK_NULL} if none)