如何在F#中执行多行Lambda表达式? [英] How to do multiline lambda expressions in f#?

问题描述

我该如何在F#中执行此操作(C#)

How would I do this (C#) in F#

public class MyClass
{
    void Render(TextWriter textWriter)
    {
        Tag(() =>
                {
                    textWriter.WriteLine("line 1");
                    textWriter.WriteLine("line 2");
                });
        Tag(value =>
                {
                    textWriter.WriteLine("line 1");
                    textWriter.WriteLine(value);
                }, "a");
    }

    public void Tag(Action action)
    {
        action();
    }
    public void Tag<T>(Action<T> action, T t)
    {
    action(t);
    }
}

推荐答案

F#中的多行lambda就是

A multi-line lambda in F# is just

(fun args ->
    lots
    of
    code
    here
)

整个代码就像

open System.IO

type MyClass() as this =
    let Render(tw : TextWriter) =
        this.Tag(fun() ->
            tw.WriteLine("line1")
            tw.WriteLine("line2")
        )
        this.Tag(fun(value : string) ->
            tw.WriteLine("line1")
            tw.WriteLine(value)
        , "a"
        )
    member this.Tag(action) = 
        action()
    member this.Tag(action, x) =
        action(x)

假设我没有任何转录错误. (我在公共接口中使用了F#函数类型，而不是Action委托.)

assuming I made no transcription errors. (I used F# function types rather than Action delegates in the public interface.)

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