protected function next_token(){
		$this->tok = next( $this->input );
		$this->t = self::token_to_symbol( $this->tok );
		return $this->tok;
	}
protected function next_token(){
		$this->tok = next( $this->input );
		$this->t = self::token_to_symbol( $this->tok );
		return $this->tok;
	}
protected function next_token ( ) { $ this -> tok = next ( $ this -> input ) ; $ this -> t = self :: token_to_symbol ( $ this -> tok ) ; return $ this -> tok ; }
Advance input stream to next token
@return Mixed next token in input stream
Advance input stream to next token