Prototypical.

I'll soon add 'Pairwise Testing' and docs, but feel free to beat me to it.

Usage

Works by key or (key, value) over Set, Arr, PairArr, Map, Obj and any other supplied type.

import * as B from "./bin.mjs"
import { D3 } from "./md.mjs"

const mkMap = o => new Map(Object.entries(o))


// [1] ∪ [2] with the result as Set = {1, 2}
B.union("Set")("Arr", [1])("Arr", [2])

// ["a"] ∩ {a: 1} with the result as Set = {a}
B.int("Set")("Arr", ["a"])("Obj", {a: 1})

// {a: 1} ∪ {b: 2} with the result as Obj = {a: 1, b: 2}
B.union("Obj")("Obj", {a: 1})("Obj", {b: 2})

// {a: 1, b: 2} - Map({a: 3}) with the result as Map = Map({b: 2})
B.sub("Map")("Obj", {a: 1, b: 2})("Map", mkMap({a: 3}))


// {a: 1, b: 2} `minus by key value` Map({a: 3}) with the result as Map
//  = Map({a: 1, b: 2})

B.subByKv("Map")("Obj", {a: 1, b: 2})("Map", mkMap({a: 3}))

// with SetTheseFn
// {a: 1, b: 2} ∪ {a: 3} with the result as Obj
//  = {a: {this: 1, that: 3}, b: {this: 2}}

B.union_(D3)("Obj")("Obj", {a: 1, b: 2})("Obj", {a: 3})

Addendum

One of my main use cases is:

const [new, existing] = manyOp()
  (["Int", "Map"], ["Sub", "Set"])("Map", a)("SArr", b)

A database tells me which hashes (eg blake3) are new; and I use this to split my input into:

• new : Map (for insertion)
• existing : Set (eg to have a datetime updated)

Notice that the ops are fused.

I'm also experimenting with having a 'Cost Algebra' help decide:

• what side to iterate to compute an intersection
• to replace has by get
• to use or add an intersection, eg for A △ B = (A - B) ∪ (B - (A ∩ B))

You can get a glimpse on these reveries on factor and nap.