# tc39/proposal-iterator-helpers

Methods for working with iterators in ECMAScript

Repository: https://github.com/tc39/proposal-iterator-helpers
Canonical: https://ross.abutalabs.com/products/proposal-iterator-helpers
Homepage: https://tc39.es/proposal-iterator-helpers
Language: HTML
License Family: other
Topics: ecmascript-proposal, tc39, javascript, iterators
Archived: true
Last push: 2024-10-08T04:41:47+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 2788, "days_push": 694, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, archived, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1348, forks 34 (observed 2026-08-28T04:04:27.705727+00:00)

## What it is
A TC39 ECMAScript language proposal specifying iterator helper methods (map, filter, take, drop, flatMap, reduce, etc.) on the Iterator prototype. The proposal reached Stage 4 and was merged into ECMA-262, so this repository is archived and no longer active.

## Use cases
- add map and filter to javascript iterators
- lazily process infinite sequences in javascript
- understand how iterator helpers work in es2025
- read the tc39 spec for iterator.prototype.take
- replace lodash-style iterator utilities with native methods
- learn how tc39 proposals advance through stages

## When to choose
- you want to read the original specification text or design rationale for iterator helpers
- you are researching the TC39 process or the history of this proposal

## When to avoid
- you want a runnable library or polyfill - use the built-in methods in modern JavaScript runtimes instead
- you need async iterator helpers - those were split into a separate proposal
- you expect active development - the repo is merged and inactive

## Facets
- artifact type: learning-resource
- maturity: abandoned
- function: programming-language, interpreter, developer-tools
- domain: programming-languages, developer-tools, documentation
- platform: browser, cross-platform
- tags: ecmascript, tc39, javascript, iterators, language-specification, stage-4-proposal, algorithms, nodejs

## Member repositories
- tc39/proposal-iterator-helpers (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:27.705727+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:42:26.990245+00:00, confidence not recorded.
  - readme: https://github.com/tc39/proposal-iterator-helpers (fetched 2026-08-28T04:04:27.705727+00:00, sha 96559c3f0b8b)
  - homepage: https://tc39.es/proposal-iterator-helpers (fetched 2026-08-29T12:01:28.096752+00:00, sha ba955f88a2e1)
- Data as of 2026-08-30T08:39:29.467469+00:00.