我如何处理 F# 中的 IEnumerable? [英] How do I deal with IEnumerable in F#?

问题描述

有很多遗留接口以纯 IEnumerable 的形式获取实体集合.通常可以在 C# 中执行 foreach(CertainTypeWeSureItemIs item in items) 将对象转换为他们想要的任何类型.IEnumerable 不会直接转换为序列.将它包装在 seq { for x in xs ->x } 也没有多大帮助，因为它得到 seq{obj}.那么我如何在 F# 中做到这一点?

There are quite a few legacy interfaces that get collections of entities in form of plain IEnumerable. Commonly one would do foreach(CertainTypeWeSureItemIs item in items) in C# casting objects to whatever type they want as they go. IEnumerable doesn't translate directly to a sequence. Wrapping it in seq { for x in xs -> x } doesn't help much either because it gets seq{obj}. So how do I do this in F#?

推荐答案

使用Seq.cast:

let al = new System.Collections.ArrayList()
al.Add(1) |> ignore
al.Add(2) |> ignore
al |> Seq.cast<int> |> Seq.iter(printf "%i")

这篇关于我如何处理 F# 中的 IEnumerable?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！