}
	}
}

// firstError returns the first error value triggered by the input.
func firstError(input *Input) (err error) {
	panicOnError = true
	defer func() {
		panicOnError = false
		switch e := recover(); e := e.(type) {
		case nil:
		case error:
			err = e
		default:
			panic(e)
		}
	}()

	for {
		tok := input.Next()
		if tok == scanner.EOF {
			return
		}
	}