csharp 可映射示例C＃

Posted 2021-05-12

typeclass Mappable<m> {
    m<b> map(Func<a, b> mapper, m<a> container);
}

typeclassinstance Mappable<List> {
    List<b> map(Func<a, b> mapper, List<a> lst) {
        if (lst.Count == 0) {
            return new List<b>();
        } else {
            a head = lst[0];
            List<a> rest = lst.Slice(1, lst.Count - 1);
            b mappedHead = mapper(head);
            return map(mapper, rest).Prepend(mappedHead);
        }
    }
}