Implement utility selectors bound to current state

[devinivy]

Resolves #2. In short, the idea is: app.actions is to app.dispatch as app.selectors is to app.select. For former binds actions to dispatch(), and the latter binds getState() to selectors.

[zemccartney]

oh, huh. what cases does returning plain value cover? is that kinda a selector to access a constant?
less a question about this PR, more about redux practice generally

[devinivy]

I didn't design it for any specific use-case. I wanted select to be identical to selectors except with any functions in there bound to state, and that lead to me just ignoring unfamiliar values. I suppose the other option would be to strip them out for select, but it seems like it would make app.select and app.selectors less "reflective" of each other.

[zemccartney]

oh, gotcha, that makes sense. thanks for explaining! 🙏

[zemccartney]

baller! 🍺 ❤️

[zemccartney]

random side-thought (taking back my "only" comment 🎺 ): maybe, in the example application, show an example of composing selectors? Not directly relevant to this, just came to mind on the topic of selectors in general. squirrel braining away!

[devinivy]

Not sure I can picture what you're thinking of, although it reminds me of some things reselect allows you to do. Can you give an example of what you mean?

[zemccartney]

ha, yea, it came to mind when I was reviewing the section in the redux docs on selectors and reselect as I was reviewing this, trying to better wrap my head around this.

But yea, for an example, something like:

const app = MiddleEnd.create({
        mods: {
            counter: {
                selectors: {
                    get: ({ counter }) => counter,
                    // Would this work?
                    cone: (inc) => app.select.counter.get() + inc
                }
        }
});

And I'm realizing now that that might not work, binding app in there like that...hmm. But yea, that's the gist of what i had in mind. No idea how useful, if functional, though 🤷‍♂

[zemccartney]

ay, actually, on the topic of reselect, what are your thoughts on supporting (down the line, not here, of course) any sort of selector memoization, whether internally or via compatibility with a tool like reselect?

[devinivy]

I would recommend using reselect for that. I don't think strange-middle-end needs to do anything special to support it. I am working on a separate library as time allows that implements selectors on normalizr entities (https://github.com/devinivy/denormie), which should work well with this library if it's ever completed. And yeah, your example above should work fine!

[zemccartney]

ooooh very cool, thanks for the early notice. Pumped to see what comes out of that 🙏

[bmleight]

I dig it!