Talk is cheap.

func reverseWords(s string) string {
    if s == "" {
        return ""
    }
    tmp := strings.Split(s, " ")
    i, j := 0, len(tmp) - 1
    for i < j {
        tmp[i], tmp[j] = tmp[j], tmp[i]
        i += 1
        j -= 1
    }
    return strings.Join(tmp, " ")
}