["Request"] DefaultedMap about arrow HOT 5 CLOSED

Is this not covered by stdlib withDefault?

from arrow.

Is this not covered by stdlib withDefault?

Didn't know about that method! 😅 That's neat and covers almost everything. There's one neat feature of having it in a wrapping class though, and that's that you can override the get method to return V instead of V?, and avoid either banging or null coalescing an output that you already know is not null.

It does make the concept a lot less useful though, as it covers most of the use-cases (and the use-case I mentioned in particular).

from arrow.

get being nullable by default is annoying. getValue exists, but sometimes I wish it'd be the default, with a getOrNull function instead. Maybe we can do something here, but it would be sort of strange to redefine all of this in Arrow just to get better typing for that one method.

This could be a good stdlib request to expose their MapWithDefault interface

from arrow.

I agree with @kyay10, this is already partially covered by Kotlin Std, and I don't think it really belongs in Arrow. Regardless of that I think MapWithDefault would be beneficial.

Beware that get doesn't actually return the value defined by withDefault { } AFAIK, and it requires using getValue. At least this used to be the case, not sure if this has been fixed yet.

This is because get is defined on Map, and doesn't use the Java's get and thus ignore the withDefault { } handler.

from arrow.

I'm going to close the issue for now, but feel free to re-open or discuss further ☺️

from arrow.