/* Increases a pointer while it points to a character that belongs to a set.  */
static char* goWhile(char *str, char const *set)
/* Increases a pointer while it points to a character that belongs to a set.  */
static char* goWhile(char *str, char const *set)
{
    for (; *str != '\0'; ++str)
    {
        if (!isOneOfThem(*str, set))
            return str;
    }
    return 0;
}