继承自Seq

Question

我想创建自己的自定义集合类型.

我将我的收藏定义为:

type A(collection : seq<string>) =
   member this.Collection with get() = collection

   interface seq<string> with
      member this.GetEnumerator() = this.Collection.GetEnumerator()

但这不编译 No implementation was given for 'Collections.IEnumerable.GetEnumerator()

我该怎么做呢？

Answer 1

在F#中,seq它实际上只是一个别名System.Collections.Generic.IEnumerable<T>.泛型IEnumerable<T>也实现了非泛型IEnumerable,因此您的F#类型也必须这样做.

最简单的方法是将非泛型调用放入通用调用中

type A(collection : seq<string>) =
  member this.Collection with get() = collection

  interface System.Collections.Generic.IEnumerable<string> with
    member this.GetEnumerator() =
      this.Collection.GetEnumerator()

  interface System.Collections.IEnumerable with
    member this.GetEnumerator() =
      upcast this.Collection.GetEnumerator()