There were several items on the agenda, this post focuses on feature proposals and their progress from the meeting that was held between March 28th-31st, 2022.
Stage 1:
Type Annotations: Enable developers to add type annotations.
Function once: Standardize
oncefunction in the language core.
Stage 2:
- Decorator metadata: Decorators can associate metadata with the value that is being decorated. (P.S: The repo shall be updated with content.)
Stage 3:
RegExp set notation + properties of strings: extend the syntax for character classes to add support for set difference/subtraction, set intersection, and nested character classes.
Change array by copy: Provides additional methods on
Array.prototypeandTypedArray.prototypeto enable changes on the array by returning a new copy of it with the change.Decorators (sans metadata): Functions called on classes, class elements, or other JavaScript syntax forms during definition.
Top comments (3)
Disappointed not to see Record & Tuple advanced, that's my most anticipated proposal at the moment. Can't wait for comparison-by-value of complex objects!
Pattern matching didn't get to accepted for stage 2? ☹️
Yeah, fingers-cross for future meetings on that one! If it's of any interest I wrote a pattern-matching library after initially learning about the TC39 proposal, trying to shoe-horn it into looking a little like the spec with varying degrees of success.