How to handle "Unknown" or "Any" type in ReasonML?


Hey there!

Does ReasonML have some sort of ANY type that can be used for helper functions if you don’t know about certain types beforehand?

E.g. I have a function that helps with http requests, that would need a type something like this:

type fetchState =
  | Loading
  | Error(fetchErr)
  | Loaded(array(ANYTHING));

Depending on the JsonDecoders I pass to the function, the return type for Loaded(array(...)) can be anything. Does anyone know how to do this with the above snippet?


Hi, @feluxe!

You’ll want to use a parameterized type for that. Here are some docs:

And here’s a clip from a book:


@splodingsocks This was exactly what I was looking for :smiley: Thanks so much!