Validator API: option(string) => Js.Result.t(unit, string)

[thangngoc89]

Currently, validator API looks like this:

Custom(state => option(string))

Which is IMHO pretty confusing and requires you to read doc/source code to actually know what is option(string) actually means.

I would suggest that we use result type. It's in OCaml 4.0.3 but Bucklescript provides us a compat type Js.Result.t

Usage:

open Js.Result;
type validateResult = Js.Result.t(unit, string);
...
Custom(values => values.password == "123" ? Error("Really") : Ok())

And I think using result type should be self-described

[fakenickels]

Sounds interesting

[fakenickels]

But for me it looks similar, using option or Result in this case.
Let's see what the others think about this

[fakenickels]

We have now something similar to this
Valid | Error(string)