F#按索引数组切片数组 [英] F# slicing array by indices array

问题描述

如何为F#数组重载.[]以基于任意索引数组对数组进行切片?

How can I overload .[] for F# array to slice an array based on an arbitrary index array?

例如:

let x = [|1..10|]; 
let indx = [|4;1|];

尽管

[| for i in indx ->x.[i]|] 

可以，直接使用x.[indx]会更好.

would work, it would be nicer to be able using x.[indx] directly.

推荐答案

您始终可以编写一个F#扩展方法以接近语法

You can always write an F# extension method to get close on the syntax

let a = [| 1..10 |]
let idx = [|4;1|]

type 'T ``[]`` with   //'
    member this.Slice(indices:int array) =
        [| for i in indices -> this.[i] |]

printfn "%A" (a.Slice idx)

但是由于数组已经有一个索引器，所以它似乎没有出现，因此有一种方法可以重载/更改它.

but since arrays already have an indexer it doesn't appear there's a way to overload/change it.

这篇关于F#按索引数组切片数组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！