通用功能签名(Generic function signatures)

通用功能签名(Generic function signatures)

我正在努力将C＃应用程序移植到F＃，我有这个界面：

public interface ISerializer { string ContentType { get; } string Serialize(object value); T Deserialize<T>(string value); }

所以我想定义一个这样的类型：

type Serializer = {ContentType: string; Serialize: Object -> string; Deserialize<'T>: string -> 'T}

但我不能。 这里的功能方式是什么？

I'm endeavouring to port a C# app to F# and I have this interface:

public interface ISerializer { string ContentType { get; } string Serialize(object value); T Deserialize<T>(string value); }

So I'd like to define a type like this:

type Serializer = {ContentType: string; Serialize: Object -> string; Deserialize<'T>: string -> 'T}

But I can't. What's the functional way here?

最满意答案

您可以在F＃中定义相同的界面，如下所示：

type ISerializer = abstract ContentType : string abstract Serialize : obj -> string abstract Deserialize<'a> : string -> 'a

没有办法使用自然的功能数据类型（如记录）获得相同的“内部”多态性，因此您必须使用OO结构。

如果您真的想要使用记录，可以为Deserialize定义一个包装Deserialize并将其放入记录中：

type IDeserializer = abstract Deserialize<'a> : string -> 'a type Serializer = { ContentType : string Serialize : obj -> string Deserializer : IDeserializer }

但我认为这不值得。

You can define the same interface in F# like this:

type ISerializer = abstract ContentType : string abstract Serialize : obj -> string abstract Deserialize<'a> : string -> 'a

There's no way to get the same "internal" polymorphism with a natural functional datatype such as a record, so you have to use the OO constructs.

If you really wanted to use a record, you could define a single wrapper for Deserialize and put that inside a record:

type IDeserializer = abstract Deserialize<'a> : string -> 'a type Serializer = { ContentType : string Serialize : obj -> string Deserializer : IDeserializer }

but I don't think it's really worthwhile.