function export(){
		if( $this->is_terminal() ){
			if( $this->t === $this->value ){
				// scalar token
				return $this->value;
			}
			// PHP Tokenizer style array
			return array( $this->t, $this->value );
		}
		// else is a branch
		$a = array();
		foreach( $this->children as $Child ){
			$a[] = array( $this->t, $Child->export() );
		}
		return $a;
	}