@thi.ng/associative/difference.js

ES Map/Set-compatible implementations with customizable equality semantics & supporting operations

import { copy } from "@thi.ng/object-utils/copy";
import { empty } from "@thi.ng/object-utils/empty";
import { __combineSet } from "./internal/combine.js";
import { into } from "./into.js";
const difference = (a, b, out) => {
  if (a === b) {
    return out || empty(a, Set);
  }
  out = out ? into(out, a) : copy(a, Set);
  for (const i of b) {
    out.delete(i);
  }
  return out;
};
function differenceR(src) {
  return __combineSet(differenceR, difference, src);
}
export {
  difference,
  differenceR
};