Collections

Collect, await, partition, and flatten Result values while preserving tuple and union types.

Result.all

Collect all successes or return the first error in input order:

const result = Result.all([Result.ok(1), Result.ok("two"), Result.ok(true)] as const);
// Result<[number, string, boolean], never>

const result = Result.all([loadUser(), loadTeam(), loadPlan()]);
// first Err short-circuits collection

The returned error is the first error encountered while iterating.

Result.allAsync

Await all inputs concurrently, then collect in input order:

const result = await Result.allAsync([
  fetchUser(id),
  fetchTeam(teamId),
  Result.ok(cachedPolicy),
] as const);

A raw rejected input Promise is a broken contract and becomes Panic. Promise-returning operations should normally catch expected rejection with Result.tryPromise before collection.

Result.partition

Keep every branch and preserve relative order:

const [users, errors] = Result.partition(results);
// users: Array<success union>
// errors: Array<error union>

Unlike all, partition never short-circuits.

Result.partitionAsync

const [users, errors] = await Result.partitionAsync(requests);

Inputs are awaited concurrently, then partitioned in input order. A rejected Promise becomes Panic.

Result.flatten

const nested: ResultType<ResultType<User, ParseError>, LoadError> = loadNested();
const flat = Result.flatten(nested);
// Result<User, ParseError | LoadError>

Prefer andThen when creating the chain. flatten is useful when a nested Result already exists.