Question

Is there a way to ‘generate’ functions like this one:

fun x -> x.ToString 

I would like to be able to turn an instance method into a static method which takes ‘this’ as a parameter, like so:

items |> Seq.filter my_predicate |> Seq.map Object.ToString 

Answer 1

this has been discussed several times on the F# hub. See for example instance methods as functions. This is quite tricky problem, so there are no plans to have something like this in the first version of F# as far as I know, but it would be great to have something like that eventually :-).

Another workaround that you could do is to add static member as an extension method in F#:

type System.Object with   static member ObjToString(o:obj) = o.ToString()  open System [ 1 .. 10 ] |> Seq.map Object.ObjToString;; 

But that is a bit ugly. Also, it seems that this works only if you use different name for the method. I guess that F# doesn’t allow you to overload existing method with an extension method and always prefer the intrinsic one.