inline assoc, dissoc, get on objects?

[borkdude]

We could do this:

{ ...{ x: 1 }, y: 2, z: 3 }

if we knew for sure that the argument map was a JS object.

dissoc:

(({ key1, key2, ...rest }) => rest)(obj)

get with default:

"a" in x ? x["a"] : 42;

Of course you could shrink the size of the above by calling rest some single char thing

(conj ^array x b c) => […x, b, c]

For Map:

const m2 = new Map([...m1, ['x', 10], ['y', 20]]);

Would be worth checking if this is any faster than a function in which we do this only for objects

• contains? -> "key" in object

• doto -> comma expression

[yuhan0]

Similar idea for merge and concat (though latter depends if you want to preserve the lazy-seq semantics from clojure):

[(merge) (merge m1) (merge m1 m2)
 (concat) (concat v1) (concat v1 v2)]
;; =>
["{}" "{...m1}" "{...m1,...m2}"
 "[]" "[...v1]" "[...v1,...v2]"]

Along with collapsing literal maps

[(merge m {:a 1}) (merge {:a 1} m) (merge {} m {})
 (concat xs [1 2 3]) (concat [1 2 3] xs) (concat [] xs [])]
;; =>
["{...m,'a':1}" "{'a':1,...m}" "{...m}"
 "[...xs,1,2,3]" "[1,2,3,...xs]" "[...xs]"]