Tc39

ECMAScript Proposals

Official repository tracking the evolution of the ECMAScript (JavaScript) language standard through its proposal stages.

Fates and StatesJavaScript

The ES6 promises specification proposal that defines the standard JavaScript Promise API for asynchronous operations.

matchAll

A JavaScript proposal for String.prototype.matchAll, providing an iterator over all regex matches with capturing groups.

flag sHTML

Adds the `s` (dotAll) flag to JavaScript regular expressions, making `.` match any character including line terminators.

flag dHTML

A Stage 4 ECMAScript proposal to add start and end indices for regex capture groups via the 'd' flag.

Legacy RegExp features

ECMAScript proposal to standardize legacy RegExp static properties like RegExp.$1 and the RegExp.prototype.compile method.

modifiersHTML

A proposal to add regular expression pattern modifiers for controlling flags like i, m, s, and x within subexpressions in ECMAScript.

Restrict subclassing support in built-ins

A TC39 proposal to remove ES6 built-in subclassing machinery (Types II, III, IV) to reduce complexity and security vulnerabilities.

Extended mode and commentsJavaScript

A TC39 proposal to add extended mode (x flag) with insignificant whitespace and comments to ECMAScript regular expressions.

Atomic operatorsJavaScript

A proposal to add atomic groups ((?>…)) and possessive quantifiers (*+, ++, etc.) to ECMAScript regular expressions for backtracking control.

Buffer boundariesHTML

Adds \A and \z escapes to ECMAScript regex for start/end of input anchors unaffected by multiline mode.