Protocols about squint

[borkdude]

This idea excites me: https://twitter.com/borkdude/status/1560711024336150528
Bringing your own immutable collections and add support via protocols for assoc etc.
This would still get you the features from CLJS but in an "unbundled" way.

[lilactown]

To clarify: the above idea could accomplish the following goals:

1. Emit far less code than we do today
2. Allow JS code to easily import and extend ClavaScript protocols
3. Allow ClavaScript code to use JS protocols like the transducer example

[borkdude]

@lilactown Sounds like good goals, but need to learn a bit more:

1. What is the benefit of using a symbol over a string here? When you create Symbol/for + a same string you will have an identical symbol and thus a conflict, similar when you would just use the string?
2. Is it really that much different from what clava generates now (based on code borrowed from CLJS)?
3. Which transducer example?

[lilactown]

1. Symbol.for is an explicit lookup in the global symbol table. It is different than someone randomly calling the object.bar method, which may have a conflict. The other thing that symbols ensure is that the properties don't show up in things like Object.keys and JSON.stringify, which is an improvement over using a long obscure string.
2. It's fairly similar in semantics, but right now Clava generates a lot more code than I wrote above. The code I wrote out also moves all handling of arity into the method implementation, rather than the protocol wrapper, which is more JS-like.
3. It's linked in the OP: cognitect-labs/transducers-js#20

[lilactown]

Other examples of built-in "protocols" that could guide us towards a more JS-like design: https://dmitripavlutin.com/detailed-overview-of-well-known-symbols/

[borkdude]

@lilactown I've read the articles and this seems the way to go forward, agreed!

[lilactown]

An amendment to the initial design: by using Symbol("Foo") instead of Symbol.for("Foo"), we no longer have to worry about collisions, since symbols constructed the former way have unique identities each time.

[lilactown]

Closing this as the general approach seems to work.

Additional issues will be opened for gaps & bugs.