dashp/src/flatmap.js

Utilities for monadic promises.

import {
  collect,
  collect2,
  collect3,
  collect4,
  collect5,
  collect6,
  collect7,
  collect8,
} from "./collect";
import {curry2} from "./internal/curry";
import flatten from "./internal/flatten";

const flatmapN = (mapper, f, xs) => mapper(f, xs).then(flatten);

export const {
  flatmap,
  flatmap2,
  flatmap3,
  flatmap4,
  flatmap5,
  flatmap6,
  flatmap7,
  flatmap8,
} = [
  collect,
  collect2,
  collect3,
  collect4,
  collect5,
  collect6,
  collect7,
  collect8,
].reduce((memo, m, i) => {
  const name = `flatmap${i === 0 ? "" : i + 1}`;
  const f = curry2(name, (g, xs) => flatmapN(m, g, xs));
  return Object.assign(memo, {[name]: f});
}, {});