call

Given a key and a set of arguments, call them when given a context. Primarily useful in composition.

Use a closure to call a stored key with stored arguments.

typescript

export const call =
  (key: string, ...args: any[]) =>
  (context: any) =>
    context[key](...args);

typescript

Promise.resolve([1, 2, 3])
  .then(call("map", (x) => 2 * x))
  .then(console.log); // [ 2, 4, 6 ]
const map = call.bind(null, "map");
Promise.resolve([1, 2, 3])
  .then(map((x) => 2 * x))
  .then(console.log); // [ 2, 4, 6 ]