Module and class with same name

Question

This is allowed:

type Test = class end

[<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
module Test = begin end

But this not:

[<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
module Test = begin end

type Test = class end

Why?

In the second case, the error is: Duplicate definition of type or module 'Test'.

I'd love to be able to define some public [<Literal>] constants that are required for a type and important for users of the type inside a module with the same name.

I don't see anything in the spec about a required order, so my guess is it's a bug. — Daniel, Jul 10 '14 at 20:27
would something like "module Test_Literals", and then "open Test_Literals" prior to type Test do the trick? — sgtz, Jul 11 '14 at 03:46

score 14 · Accepted Answer · answered Jul 11 '14 at 16:48

14

You can open the type declaration, close it and re open later, something like this:

type Test = class end

[<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
module Test =
    [<Literal>]
    let myLiteral = "myLiteral"

type Test with
    static member test = ()

I use this trick all the time ;)

answered Jul 11 '14 at 16:48

Gus

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That's a neat trick. Fixing a duplicate definition error by introducing another duplicate definition... well done, sir! But I guess it only works with type extensions? Nevertheless, this is totally usable in my case... – Nikon the Third Jul 11 '14 at 19:39
3

@NikontheThird it looks like a type extension but it is not. As long as it is in the same file the F# compiler puts everything together. – Gus Jul 11 '14 at 21:24
@Gustavo thanks for the nice trick, however it doesn't work when "Test" is a record type..which I do find needed occasionally. – trek42 Aug 10 '14 at 14:37

Module and class with same name

1 Answers1