从C#调用F#代码

我正在玩F#和C#,并想从C#调用F#代码。

我设法通过在Visual Studio中有两个项目在相同的解决scheme中,并将C#代码的引用添加到F#项目中,以相反的方式工作。 做完这些之后,我可以调用C#代码,甚至在debugging的时候通过它。

我想要做的是F#代码从C#而不是C#代码从F#。 我在F#项目中添加了一个对C#项目的引用,但是它不像以前那样工作。 我想知道这是否可能,而不需要手动。

(编辑:我最初链接到这些文件外部,但我的SVN主机不再允许匿名访问,所以现在代码是内联在这个答案。

下面是从C#调用F#的一个工作示例。

正如您所遇到的,我无法通过从“添加引用…项目”选项卡中进行select来添加引用。 相反,我必须手动执行,通过浏览到“添加引用…浏览”选项卡中的F#程序集。

—— F#MODULE —–

// First implement a foldl function, with the signature (a->b->a) -> a -> [b] -> a // Now use your foldl function to implement a map function, with the signature (a->b) -> [a] -> [b] // Finally use your map function to convert an array of strings to upper case // // Test cases are in TestFoldMapUCase.cs // // Note: F# provides standard implementations of the fold and map operations, but the // exercise here is to build them up from primitive elements... module FoldMapUCase.Zumbro #light let AlwaysTwo = 2 let rec foldl fn seed vals = match vals with | head :: tail -> foldl fn (fn seed head) tail | _ -> seed let map fn vals = let gn lst x = fn( x ) :: lst List.rev (foldl gn [] vals) let ucase vals = map String.uppercase vals 

—– C#unit testing模块—–

 // Test cases for FoldMapUCase.fs // // For this example, I have written my NUnit test cases in C#. This requires constructing some F# // types in order to invoke the F# functions under test. using System; using Microsoft.FSharp.Core; using Microsoft.FSharp.Collections; using NUnit.Framework; namespace FoldMapUCase { [TestFixture] public class TestFoldMapUCase { public TestFoldMapUCase() { } [Test] public void CheckAlwaysTwo() { // simple example to show how to access F# function from C# int n = Zumbro.AlwaysTwo; Assert.AreEqual(2, n); } class Helper<T> { public static List<T> mkList(params T[] ar) { List<T> foo = List<T>.Nil; for (int n = ar.Length - 1; n >= 0; n--) foo = List<T>.Cons(ar[n], foo); return foo; } } [Test] public void foldl1() { int seed = 64; List<int> values = Helper<int>.mkList( 4, 2, 4 ); FastFunc<int, FastFunc<int,int>> fn = FuncConvert.ToFastFunc( (Converter<int,int,int>) delegate( int a, int b ) { return a/b; } ); int result = Zumbro.foldl<int, int>( fn, seed, values); Assert.AreEqual(2, result); } [Test] public void foldl0() { string seed = "hi mom"; List<string> values = Helper<string>.mkList(); FastFunc<string, FastFunc<string, string>> fn = FuncConvert.ToFastFunc((Converter<string, string, string>)delegate(string a, string b) { throw new Exception("should never be invoked"); }); string result = Zumbro.foldl<string, string>(fn, seed, values); Assert.AreEqual(seed, result); } [Test] public void map() { FastFunc<int, int> fn = FuncConvert.ToFastFunc((Converter<int, int>)delegate(int a) { return a*a; }); List<int> vals = Helper<int>.mkList(1, 2, 3); List<int> res = Zumbro.map<int, int>(fn, vals); Assert.AreEqual(res.Length, 3); Assert.AreEqual(1, res.Head); Assert.AreEqual(4, res.Tail.Head); Assert.AreEqual(9, res.Tail.Tail.Head); } [Test] public void ucase() { List<string> vals = Helper<string>.mkList("arnold", "BOB", "crAIg"); List<string> exp = Helper<string>.mkList( "ARNOLD", "BOB", "CRAIG" ); List<string> res = Zumbro.ucase(vals); Assert.AreEqual(exp.Length, res.Length); Assert.AreEqual(exp.Head, res.Head); Assert.AreEqual(exp.Tail.Head, res.Tail.Head); Assert.AreEqual(exp.Tail.Tail.Head, res.Tail.Tail.Head); } } } 

它应该“正常工作”,尽pipe在从C#作品引用项目之前可能需要构buildF#项目(我忘记了)。

问题的一个常见来源是名称空间/模块。 如果你的F#代码不是以一个名字空间声明开始,它会被放在一个与文件名同名的模块中,所以,例如从C#中你的types可能会显示为“Program.Foo”而不是“Foo”(如果Foo是Program.fs中定义的F#types)。

从这个环节看,他们似乎有一些可能的解决scheme,但似乎最简单的是这样的评论 :

F#代码:

 type FCallback = delegate of int*int -> int;; type FCallback = delegate of int * int -> int let f3 (f:FCallback) ab = f.Invoke(a,b);; val f3 : FCallback -> int -> int -> int 

C#代码:

 int a = Module1.f3(Module1.f2, 10, 20); // method gets converted to the delegate automatically in C# 

// Test.fs:

 module meGlobal type meList() = member this.quicksort = function | [] -> [] // if list is empty return list | first::rest -> let smaller,larger = List.partition((>=) first) rest List.concat[this.quicksort smaller; [first]; this.quicksort larger] 

// Test.cs:

 List<int> A = new List<int> { 13, 23, 7, 2 }; meGlobal.meList S = new meGlobal.meList(); var cquicksort = Microsoft.FSharp.Core.FSharpFunc<FSharpList<IComparable>, FSharpList<IComparable>>.ToConverter(S.quicksort); FSharpList<IComparable> FI = ListModule.OfSeq(A.Cast<IComparable>()); var R = cquicksort(FI);