F# Type Provider compiled as *.exe file

Question

Why I cannot create Type Provider as *.exe file with [<TypeProviderAssembly()>] and [<EntryPoint>] inside?

When I try to reference such TP using #r @"d:\TP\bin\Debug\MyTypeProvider.exe", I see the following:

test.fsx(3,1): error FS3031: The type provider 'd:\TP\bin\Debug\MyTypeProvider.exe' reported an error: Assembly attribute 'TypeProviderAssemblyAttribute' refers to a designer assembly 'MyTypeProvider' which cannot be loaded or doesn't exist. Could not load file or assembly 'file:///d:\TP\bin\Debug\MyTypeProvider.dll' or one of its dependencies. The system cannot find the file specified.

I need to have a type inference runtime in separate process, because it should be 64bit (unlike 32bit VS process). But I want to pack all things into one file, reference it from VS and start as external process.

Answer 1

Perhaps there's some good underlying reason for always looking for DLLs instead of EXEs, but I suspect this may be an arbitrary limitation.

I can get things to work in FSI if I supply the assembly's full name to the TypeProviderAssemblyAttribute constructor (e.g. [<TypeProviderAssembly("MyExe, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null")>]), but IntelliSense doesn't work and I can't use the TP from other projects. Consider filing a bug with the team - but it would probably help if you could justify why you need an EXE instead of a DLL for your scenario.