如何快速生成列表迭代文件(how to generate a list quickly iterating a file)

如何快速生成列表迭代文件(how to generate a list quickly iterating a file)

我来自ac＃和python背景，觉得必须有更好的方法来读取文件并填充经典的F＃列表。 但后来我知道af #list是不可变的。 必须有一个使用List<string>对象并调用其Add方法的替代方法。

到目前为止，我手头有：

let ptr = new StreamReader("stop-words.txt") let lst = new List<string>() let ProcessLine line = match line with | null -> false | s -> lst.Add(s) true while ProcessLine (ptr.ReadLine()) do ()

如果我在python中编写类似的东西，我会做类似的事情：

[x[:-1] for x in open('stop-words.txt')]

Me coming from a c# and python background, feels there must be a better way to read a file and populate a classic F# list. But then I know that a f# list is immutable. There must be an alternative using a List<string> object and calling its Add method.

So far what I have at hand:

let ptr = new StreamReader("stop-words.txt") let lst = new List<string>() let ProcessLine line = match line with | null -> false | s -> lst.Add(s) true while ProcessLine (ptr.ReadLine()) do ()

If I were to write the similar stuff in python I'd do something like:

[x[:-1] for x in open('stop-words.txt')]

最满意答案

简单解决方案

System.IO.File.ReadAllLines(filename) |> List.ofArray

虽然你可以写一个递归函数

let processline fname = let file = new System.IO.StreamReader("stop-words.txt") let rec dowork() = match file.ReadLine() with |null -> [] |t -> t::(dowork()) dowork()

Simple solution

System.IO.File.ReadAllLines(filename) |> List.ofArray

Although you can write a recursive function

let processline fname = let file = new System.IO.StreamReader("stop-words.txt") let rec dowork() = match file.ReadLine() with |null -> [] |t -> t::(dowork()) dowork()