Cannot export a type from inside a functor call

[Tomi Saarinen]

At least in flow, exporting a type inside a functor call does not generate gentype output. Is this intended?

// To reproduce, define some functor that requires type(s) as parameter
module type Config = {
  type inputType 
}
module Make = (Config: Config) => {
  type inputType = Config.inputType
}

// Works as expected, if export is done outside of the functor
export type myType = [ #var1 | #var2 ]
module Foo1 = Make({
  type inputType = myType
})

// Does not generate any .gen output.
module Foo2 = Make({
  export type inputType = [ #var1 | #var2 ]  
})

It'd be very nice if the latter example worked (if it's not techically really hard/impossible) as it does not pollute the root module namespace.

It seems if I try to refer to Foo2.inputType from another file, the callsite gentype code is generated just nice. Just the export side is missing

[Cristiano Calcagno]

Consider that annotations (export == @genType annotation) are not propagated by the type checker.

[Cristiano Calcagno]

This means that the argument to Foo gets lost into the functor application.
If you declare the argument module M separately and then pass it to the functor, is what's generated useful for what you had in mind?

[Tomi Saarinen]

Did you mean this?

module FooInput = {
  export type myType = [ #var1 | #var2 ]
}
module Foo1 = Make({
  module Input = FooInput
})

So if it's so that the type that's defined inside a functor does not exist after the functor application, then this is indeed probably the second best alternative.

Thanks for the info.