private function next()
    {
        if (!$this->valid()) {
            return;
        }

        ++$this->cursor;
        $this->current = $this->next;
        $this->next = isset($this->string[$this->cursor + 1]) ? $this->string[$this->cursor + 1] : null;
    }
private function next()
    {
        if (!$this->valid()) {
            return;
        }

        ++$this->cursor;
        $this->current = $this->next;
        $this->next = isset($this->string[$this->cursor + 1]) ? $this->string[$this->cursor + 1] : null;
    }
private function next ( ) { if ( ! $ this -> valid ( ) ) { return ; } ++ $ this -> cursor ; $ this -> current = $ this -> next ; $ this -> next = isset ( $ this -> string [ $ this -> cursor + 1 ] ) ? $ this -> string [ $ this -> cursor + 1 ] : null ; }
Advances the cursor to the next position.
Advances the cursor to the next position .