Clojurians Log v2

Is it just me or is there no convenience functions to create Maybe or Either from something potentially nullable?

Can you give any example of that you are doing?

Basically something like this:

(let [result (something-that-might-return-null ...)]
  (if result
    (just result)
    (nothing)))

And that's quite verbose and I was wondering if I was missing a convenience function that could encapsulate that

(and something analogous for Either where you would specify the Left value if the result was nil)

I agree for Maybe but not for Either

That behavior for either is too much opinionated

Well, I partly agree that Either is more semantically rich than Maybe here and there's more reason to handle both Right and Left by hand

the cats.monad.exception already provides a "Either" analogous abstraction just for succes and failure and also provides a try-on macro that allows easy wrap any result in a proper type

(exc/try-on (somethird-party-fn-that-raises-exceptions))

note that nil already participates in the Maybe abstraction, is equivalent to Nothing

Right!

I forgot about it...

for use that you just need to (require '[cats.builtin])

And then I don't have to wrap it by hand every time? I see.

hmm

no, I think we should create the analogous try-on macro for maybe for that...

the nil is treated as nothing, but any other value is not treated as Just...

I see, I'll just keep doing the manual wrapping for now then

Nice!

We surelly add the helper for the next version

we could call it ensure-maybe, its behavior will be similar to core's ensure-reduced

Since you already have maybe/from-maybe then maybe to-maybe or from-nullable could be a good choice as well?

I dig to-maybe 👍, happy to merge a patch with these additions

I've opened an issue to not forget about it https://github.com/funcool/cats/issues/133

Hmm

to-maybe is ok, but I'm will be more happy with something like try-on naming

to maybe is just a conversion, but I think it can be a macro

just for avoid additional call stack frame

or provide the two variants, macro and function

that is possible in cljs...