Splits outcomes into their successes and their failures, keeping both.

This is the shape most batch work actually wants, and the one Promise.all cannot give you: a rejected Promise.all discards the settled successes alongside the other failures. Task.results produces exactly the array this consumes.

import * as Result from './index.ts';
import { Task } from '../task/index.ts';
import * as Failure from './failure.ts';

const Rejected = Failure.define('Rejected', (d: { path: string }) => `rejected ${d.path}`);
const load = (path: string) =>
  Task<string, Failure.Of<typeof Rejected>>(() => {
    if (!path.startsWith('a')) throw Rejected({ path });
    return path;
  });

const outcomes = await Task.results(['a.json', 'b.json'].map(load));
const { values, errors } = Result.partition(outcomes); // ['a.json'] / [Failure(Rejected)]