Clojurians Log v2

Never looked at using them for keywords - mostly because they are relatively new feature - but also it would take a bit of work to assess the performance / code size tradeoffs.

Also, it seems strange to be explicitly returning true, and not just defining:

(defn key-test [key other]
  (or (identical? key other) (keyword-identical? key other) (= key other)))

identical? in CLJS compiles to a very efficient JS check which is basically free

cljs.user=> (str (fn [] (identical? 1 2)))
"function (){\nreturn ((1) === (2));\n}"

not completely free, but I think I have yet to meet the first person who made a noticeable optimization by skipping such a test

Yup. I've been looking at the code for the function:

function cljs$core$key_test(key,other){
if((key === other)){
return true;
} else {
if(cljs.core.keyword_identical_QMARK_(key,other)){
return true;
} else {
return cljs.core._EQ_.cljs$core$IFn$_invoke$arity$2(key,other);

}
}
}

I'm looking for something else, and it just struck me as "odd" that it gets tested for identical? twice

cljs.user=> (keyword-identical? 1 1)
true

Then I realized that the cond returning explicit true seemed like a strange pattern as well. There's no problem per se, but I wondered if there was something going on here, and thought I'd ask

google closure would optimize that (the if return true stuff), esbuild would too I think. this is what esbuild makes of it:

function cljs$core$key_test(e,r){return e===r||cljs.core.keyword_identical_QMARK_(e,r)?!0:cljs.core._EQ_.cljs$core$IFn$_invoke$arity$2(e,r)}

right there are some patterns you should not copy from core - or generated suboptimal code for a very long time

This is useful to know! Thank you

in general code around the persistent stuff looks odd because it's concerned about codegen

I'm looking at some of the differences between PersistentHashMap on Clojure and ClojureScript. Part of it is due to following:

clj=> (identical? :a :a)
true

cljs=> (identical? :a :a)
false

So that's why I'm in that code right now

I do appreciate that keywords differ because ClojureScript doesn't have interning for them

@dnolen did you ever look into https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol for implementing keywords?