> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solved.gg/llms.txt
> Use this file to discover all available pages before exploring further.

# ES scope

> What full ECMAScript compatibility includes and excludes for scripty pre-v0.0.1.

# ES scope

This page defines the **I1** conformance boundary. If a feature is outside this boundary, it does not block the language half of `0.0.1` — but it must still be listed honestly if users might expect it.

## Spec pin

| Item                     | Value                                                                                              |
| ------------------------ | -------------------------------------------------------------------------------------------------- |
| **Language**             | ECMAScript                                                                                         |
| **Edition**              | **2026** (ECMA-262 **17th edition**, June 2026)                                                    |
| **Specification (HTML)** | [262.ecma-international.org/17.0](https://262.ecma-international.org/17.0/)                        |
| **Catalog**              | [ECMA-262](https://ecma-international.org/publications-and-standards/standards/ecma-262/)          |
| **Pin date**             | 2026-07-17 (program start)                                                                         |
| **Re-pin trigger**       | Ecma publishes a newer ECMA-262 edition **or** we choose to claim a newer edition in release notes |

When re-pinning:

1. Update [Sources](/scripty/v0.0.1-dev/reference/sources) (edition snapshot URL + date)
2. Diff the feature matrix for new rows
3. Bump Test262 pin to a matching suite revision
4. Update engineering `docs/es-pin.md` + `docs/matrix/language.md` in the scripty repo
5. Open engineering work for deltas — do not claim the new edition until matrices catch up

## In scope (blocks language gate)

| Category               | Examples                                                                                                                                                                              |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Syntax**             | Modules, classes, async/await, generators, private fields/methods, optional chaining, nullish coalescing, top-level await, decorators **if** in the pinned edition as normative, etc. |
| **Types & values**     | Undefined, Null, Boolean, String, Number, BigInt, Symbol, Object                                                                                                                      |
| **Execution**          | Environments, this binding, strict mode as required, completion records, exceptions                                                                                                   |
| **Built-ins**          | Standard library objects required by the edition (see [Built-ins](/scripty/v0.0.1-dev/es/builtins))                                                                                   |
| **Iteration**          | Iterators, async iterators, Iterator helpers (ES2025+), generator objects                                                                                                             |
| **Collections**        | Map, Set, WeakMap, WeakSet + edition methods (e.g. Set methods)                                                                                                                       |
| **Binary data**        | ArrayBuffer, SharedArrayBuffer (if required), DataView, TypedArrays                                                                                                                   |
| **Meta**               | Proxy, Reflect, `Symbol.*` well-known symbols as required                                                                                                                             |
| **Modules (language)** | ESM parse/link/evaluate, cyclic graphs, import attributes as required by the edition                                                                                                  |
| **Promises jobs**      | Promise reaction jobs as specified (host may provide job queue; semantics must match)                                                                                                 |

## Annex B policy

| Choice                       | Policy                                                                                       |
| ---------------------------- | -------------------------------------------------------------------------------------------- |
| **Default**                  | Annex B features are **opt-in per row**                                                      |
| **To claim Annex B support** | Row must be `supported`/`dogfooded` with tests                                               |
| **If unimplemented**         | Mark `unsupported` and fail closed — do not silently accept Annex B syntax without semantics |

Document each Annex B decision in the [feature matrix](/scripty/v0.0.1-dev/es/feature-matrix).

## Explicitly out of scope for I1

| Category                                                  | Reason                                                       |
| --------------------------------------------------------- | ------------------------------------------------------------ |
| DOM / CSSOM / HTML globals                                | Not ECMAScript language; browser hosts only                  |
| Web APIs beyond language built-ins (e.g. `fetch` as host) | Host / runtime layers — not the ES language bar              |
| Node / Bun / Deno exclusive APIs                          | I2 / I3 / Node matrices                                      |
| Full Test262 **host** tests that require HTML             | Not language kernel                                          |
| Non-Linux platforms                                       | Permanent product lock                                       |
| Optimizing JIT                                            | Performance track; not required for language correctness bar |
| TypeScript typechecking                                   | Type strip is a transform layer, not ES                      |

Host-provided job scheduling, timers (`setTimeout`), and I/O are **runtime** concerns. I1 requires that **when** the host enqueues Promise jobs, Promise semantics match the spec. Timer APIs themselves are not ES language features.

## “Fully compatible” checklist

Use this checklist in release review:

* [ ] Edition pin matches claimed release notes
* [ ] Test262 pin recorded; CI green for in-scope set
* [ ] Zero open blockers on in-scope failures
* [ ] Feature matrix has no in-scope `unsupported` or `partial` rows
* [ ] Annex B policy rows reviewed
* [ ] No marketing claim of browser or npm completeness

## Relationship to internal matrices

The scripty repo keeps engineering matrices under `docs/matrix/language.md`. This public matrix is the **program-facing** source of truth for the ES2026 goal. When they disagree, update both in the same change set.


## Related topics

- [Principles](/scripty/v0.0.1-dev/principles.md)
- [Pre-v0.0.1 program](/scripty/v0.0.1-dev/index.md)
- [ES phases](/scripty/v0.0.1-dev/es/phases.md)
- [I1 — ES Engine](/scripty/v0.0.1-dev/es/index.md)
- [ES feature matrix](/scripty/v0.0.1-dev/es/feature-matrix.md)