DEV Community: hemanth.hm

Updates from the 105th TC39 meeting

hemanth.hm — Fri, 06 Dec 2024 13:37:18 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 105th TC39 meeting [2th-5th December 2024].

Stage 4

Intl.DurationFormat Provides a way to format a duration (e.g., "1 hour, 30 minutes") in a locale-sensitive manner.

new Intl.DurationFormat("fr-FR", { style: "long" }).format({
    hours: 1,
    minutes: 46,
    seconds: 40,
});
// => "1 heure, 46 minutes et 40 secondes"

Stage 3

Error.isError Adds a static isError method to check whether a given value is an instance of the Error object.

Error.isError(undefined); // false
Error.isError(isError(new Error()); // true

Stage 2.7

ESM Phase Imports Enhances the ECMAScript Module (ESM) system with new import capabilities to streamline inter-module dependency declarations.

import source myModule from "./my-module.js";

// `{ type: 'module' }` can be inferred since myModule is a module object
const worker = new Worker(myModule);

P.S: Note this is a conditional approval.

Stage 2

Immutable ArrayBuffer Introduces the concept of immutable ArrayBuffer to prevent mutation of binary data after creation.

Object.freeze(new Uint8Array(buf.transferToImmutable()));

Intl Currency Display Choices Expands options for displaying currency values, such as adding control over currency symbols and code styles.

const formal = new Intl.NumberFormat("en-US", {
  style: "currency",
  currency: "USD",
  currencyDisplay: "formalSymbol",
});
formal.format(42); // "US$42.00"

const never = new Intl.NumberFormat("en-US", {
  style: "currency",
  currency: "USD",
  currencyDisplay: "never",
});
never.format(42); // "42.00"

Stage 1

Import Sync An explicit synchronous import function for ES modules, building on the synchronous execution behavior defined by the Defer Import Eval proposal.

let react;
try {
  react = import.sync('react');
} catch {}

if (react) {
  // Bind to the React framework, if available
}

Stabilize New integrity "level" protecting against both override mistakes and proxy reentrancy

Hemanth HM

Updates from the 104th TC39 meeting

hemanth.hm — Tue, 15 Oct 2024 22:16:19 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 104th TC39 meeting [8th-10th October 2024].

Stage 1:

Representing Measures: Proposal to format and represent measurements with proper units in JavaScript.
Immutable ArrayBuffers: Adds immutable variants of ArrayBuffer to ensure buffer contents cannot be changed.
Array.zip: A method that creates an array of arrays, where each sub-array contains elements at the same index from multiple input arrays.

Stage 2:

Iterator chunking: Adds a utility to create chunks from iterators, returning fixed-size groups of elements.
Extractors: Provides utilities for data extraction, allowing structured data to be parsed and manipulated.
Structs: Introduces structured data types that are more predictable and memory-efficient for JavaScript.

Stage 2.7:

Error.isError: Enhances the Error.isError method for better error detection.
Iterator Sequencing: Adds sequencing utilities to iterators, allowing more control over execution order.

Stage 3:

Atomics.pause: Introduces a mechanism to pause execution at atomic operations for concurrency management.

Stage 4:

Promise.try: Provides a utility to handle synchronous exceptions within promises more easily.
Sync Iterator Helpers: Extends iterators with helper methods to improve their usability in synchronous contexts.
Import Attributes: Proposal for syntax to import ES modules with assertions
JSON modules: Proposal to import JSON files as modules.
RegExp Modifiers: Enhances regular expressions with additional modifiers, allowing more flexible pattern matching.

Additionally The TG4 source maps spec got conditional consensus.

Hemanth HM

Updates from the 102nd TC39 meeting

hemanth.hm — Fri, 14 Jun 2024 14:57:17 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 101th TC39 meeting [11-13th June 2024].

Stage 2:

Error.isError: Error.isError tests if a value is an Error instance, irrespective of its Realm origin.
ESM Phase Imports: Solves the static worker module analysis problem for JavaScript, through defining suitable phase imports for Source Text Module.
Discard Bindings: Discard void bindings.
Iterator Sequencing: create iterators by sequencing existing iterators

Stage 2.7:

Deferred Import Evaluation: a way to defer evaluate of a module.
Joint Iteration:synchronise the advancement of multiple iterators
RegExp.escape: proposal seeks to investigate the problem area of escaping a string for use inside a Regular Expression.

Stage 3:

Promise.try: an ergonomic, readable, and intuitive way to invoke a function and always get a Promise.

Hemanth HM

Updates from the 101th TC39 meeting

hemanth.hm — Fri, 12 Apr 2024 18:23:43 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 101th TC39 meeting [8-11th April 2024].

Stage 1:

Error.isError: Error.isError tests if a value is an Error instance, irrespective of its Realm origin.
Signals: A declarative programming model for updating based on changes to state.
Strict using: Proposal to mandate the use of using for certain resources.

Stage 2.7:

Math.sumPrecise: summation method.
Promise.try: an ergonomic, readable, and intuitive way to invoke a function and always get a Promise.

Stage 3:

Redeclarable global eval-introduced vars: Make eval-introduced global vars redeclarable.
Dynamic code brand checks:Flexible brand checks before dynamic code loading.

Stage 4:

Set Methods: New Set methods
Duplicate named capture groups: allow regex capturing group names to be repeated

Hemanth HM

Updates from the 100th TC39 meeting

hemanth.hm — Thu, 08 Feb 2024 22:52:01 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 99th TC39 meeting [6-8th Feb 2024].

Stage 1:

Iterator Unique: add a method to iterators to produce an iterator of only its unique values.
Micro and mini waits: Micro and mini waits in JS.
Joint Iteration: synchronise the advancement of multiple iterators.
iterator chunking: add a method to iterators for producing an iterator of its subsequences.
Improved Escapes for Template Literals: raw string literals that can contain any arbitrary text.
Math.sum: add a method to sum multiple values.
Module Sync Assert: Attempting to resolve issues with an async module in the dependency graph causing bugs or breaking changes in the current module.
ESM Phase Imports: Solves the static worker module analysis problem by defining phase imports for Source Text Module.
Function and Object Literal Decorators: Decorators for Function Expressions and Declarations.
Discard" (void) Bindings: void discard bindings for ECMAScript

Stage 2:

Promise.try:an ergonomic, readable, and intuitive way to invoke a function and always get a Promise.

Stage 3:

Uint8Array to/from Base64: Uint8Array<->base64/hex.

Stage 4:

ArrayBuffer: ArrayBuffer.prototype.transfer and friends.

To Inactive State:

Math Extensions: Math Extensions.
Generator arrow functions: Generator arrow functions.
Math.signbi: IEEE-754 sign bit.

@gnumanth

Updates from the 99th TC39 meeting

hemanth.hm — Fri, 01 Dec 2023 02:51:48 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 99th TC39 meeting [27-30 November 2023].

Stage 4:

Array Grouping: A proposal to make grouping of array items easier
Promise.withResolvers: Returns a promise with its resolution and rejection functions exposed.

Stage 1:

Math.sum: add a method to sum multiple values.
Module Sync Assert: Attempting to resolve issues with an async module in the dependency graph causing bugs or breaking changes in the current module.
ESM Phase Imports: Solves the static worker module analysis problem by defining phase imports for Source Text Module.

Withdrawn proposals:

@gnumanth

Updates from the 98th TC39 meeting

hemanth.hm — Fri, 29 Sep 2023 05:28:48 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 97th TC39 meeting [26-28 September 2023].

Stage 4:

Resizable ArrayBuffer: Resizable and growable ArrayBuffers.

Sage 2:

ShadowRealm: ECMAScript Proposal, specs, and reference implementation for Realms [Stage 3 -> 2].
RegExp.escape: Proposal for investigating RegExp escaping for the ECMAScript standard.

Stage 1:

Joint Iteration: synchronise the advancement of multiple iterators.
Locale Extensions:Allow Web platform engines to use limited system-defined user preferences.
Iterator Sequencing: Create iterators by sequencing existing iterators.
Negated in and instanceof:negated in and instanceof operators.
Stable Formatting: Stable Intl-inspired formatting options.

Withdrawn:

FinalizationRegistry#cleanupSome: This method was planning to enable library authors to clean up without yielding to the event loop.
Symbol.thenable: Was planning to avoid thenable behavior, a modifier should be added to an object for Promise.resolve awareness.

@gnumanth

Updates from the 97th TC39 meeting

hemanth.hm — Thu, 13 Jul 2023 17:45:59 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 97th TC39 meeting [Jul 11 - Jul 13 of 2023].

Stage 3:

Array Grouping: A proposal to make grouping of array items easier.
Promise.withResolvers: Creates a Promise with the reject,resolveandpromise functions placed as methods
on the promise object itself.
Source Phase Imports: Proposal to enable importing modules at the source phase.
Time Zone Canonicalization: Stacked on Temporal to improve handling of changes to the IANA Time Zone Database.

Stage 2:

Deferred Import Evaluation:a way to defer evaluate of a module (previously known as "Lazy Module Initialization").

Stage 1:

DataView get/set Uint8Clamped methods: getUint8Clamped and setUint8Clamped on DataView.prototype.
Optional Chaining assignment: add support for optional chaining on the left of assignment operators: a?.b = c.

Updates from the 96th TC39 meeting

hemanth.hm — Fri, 19 May 2023 00:47:56 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 96th TC39 meeting [May 16 - May 18 of 2023].

Stage 4:

Atomics.waitAsync: asynchronous atomic wait.
RegExp v flag: RegExp v flag with set notation + properties of strings"
Well-Formed Unicode Strings: method to determine if a String is well-formed Unicode.

Stage 3:

Decorator Metadata: Extend the Decorators proposal by adding the ability for decorators to associate metadata with the value being decorated.
Float16Array: Float16 on TypedArrays, DataView, Math.f16round

Stage 2:

Base64 for Uint8Array:ArrayBuffer to/from Base64
Promise.withResolvers: Creates a Promise with the reject,resolveandpromise functions placed as methods
on the promise object itself.
Time Zone Canonicalization: TC39 Proposal (stacked on Temporal) to improve handling of changes to the IANA Time Zone Database.

Stage 1:

Intl.ZonedDateTimeFormat: Intl Format for Temporal.ZonedDateTime

Updates from the 95th TC39 meeting

hemanth.hm — Fri, 24 Mar 2023 00:58:36 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 95th TC39 meeting.

Stage 3:

Async Explicit Resource Management: Address a common pattern in software development regarding the lifetime and management of various resources (memory, I/O, etc.).
import attribute: Import Assertions re-adanced to Stage-3. Proposal for syntax to import ES modules with options, e.g. for JSON modules.

Stage 2:

Async Context: proposal is to provide a mechanism to ergonomically track async contexts in JavaScript.
Float16Array: Float16 on TypedArrays, DataView, Math.f16round.
Iterator.range: A proposal for ECMAScript to add a built-in Iterator.range()

Stage 1:

Await Dictionary: A proposal to add Promise.ownProperties(), Promise.fromEntries()
Class Method Parameter Decorators: Decorators for ECMAScript class method and constructor parameters
Promise.withResolvers: Creates a Promise with the reject,resolveandpromise functions placed as methods
on the promise object itself.
Time Zone Canonicalization: TC39 Proposal (stacked on Temporal) to improve handling of changes to the IANA Time Zone Database.

@gnumanth

Elections for the 2023 TC39 Chair Group are complete 🎉

The Chairs this year are...

🔸 @SoftwareChrisGo Chris de Almeida (IBM)
🔸 @robpalmer2 Rob Palmer (Bloomberg)
🔸 @ryzokuken Ujjwal Sharma (Igalia)
— TC39 (@TC39) March 22, 2023

Updates from the 94th TC39 meeting

hemanth.hm — Thu, 02 Feb 2023 20:29:09 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the 94th TC39 meeting.

Stage 4:

Change Array by Copy: Provides additional methods on Array.prototype and TypedArray.prototype to enable changes on the array by returning a new copy of it with the change.
Intl.NumberFormat V3: Additional features for Intl.NumberFormat to solve key pain points.
Symbols as WeakMap keys: Permit Symbols as keys in WeakMaps, entries in WeakSets and WeakRefs, and registered in FinalizationRegistries

Stage 3:

ArrayBuffer transfer: proposal to add ‘ArrayBuffer.prototype.transfer’ (transfer, transferToFixedLength, detached)

Stage 2:

Import Assertions: Proposal for syntax to import ES modules with assertions (P.S: Important to note import assertions was demoted from stage 3) Details
Intl era/monthCode: To specify necessary details about era, eraYear and monthCode usage with Temporal in internationalization setting (for calendars other than iso8601)
Symbol Predicates: proposal to introduce ways to differentiate symbols.

Stage 1:

Async Context: proposal is to provide a mechanism to ergonomically track async contexts in JavaScript.
Proto pollution mitigation: Symbol.proto proposal to prevent prototype pollution by introducing a secure mode that only allows prototypes to be accessed through methods or symbol keys, not string property keys. This aims to increase security by making it harder for prototypes to be manipulated maliciously.

P.S: “Iterator helpers” was split into sync (stage 3) and async (stage 2).

Updates from the 93rd TC39 meeting

hemanth.hm — Fri, 02 Dec 2022 23:45:50 +0000

There were several items on the agenda, this post focuses on feature proposals and their progress from the meeting that was held between 29th November to 1st December 2022

Stage 4:

Intl Enumeration API: Return supported values of options, such as timeZone, calendars, numberingSystems, currencies, units

Stage 3:

Set Methods: Proposal for new Set methods.
Explicit Resource Management: Address a common pattern in software development regarding the lifetime and management of various resources (memory, I/O, etc.).
Iterator Helpers: Methods for working with iterators.
Well-Formed Unicode Strings: Method to determine if a String is well-formed Unicode.

Stage 2:

eraDisplay option for Intl.DateTimeFormat: Intl.DateTimeFormat displays era field only if date displayed is in same era as today's.
Async Explicit Resource Management: This proposal relates to async functionality deferred from the original Explicit Resource Management proposal and shares the same motivation.
ArrayBuffer.prototype.transfer: This proposal is spun out of the resizable buffer's proposal.

Stage 1:

Mass Proxy Revocation: Proposal for revoking proxies en masse.
Intl Era and MonthCode: To specify necessary details about era, eraYear and monthCode usage with Temporal in internationalization setting (for calendars other than "iso8601").
Intl.MessageResource: This proposal aims to make it easier to localize the web, increasing the openness and accessibility of the web for speakers of all languages.

[@gnumanth](https://twitter.com/gnumanth)