You keep repeating this throughout the thread. Can you give an example?

export type SemVer = `${number}.${number}.${number}`;

Could you extend it to work with regex groups like:

export const SemVerRegex = /^(?<major>0|[1-9]\d)\.(?<minor>0|[1-9]\d)\.(?<patch>0|[1-9]\d)(?:-((?:0|[1-9]\d|\d[a-zA-Z-][0-9a-zA-Z-])(?:\.(?:0|[1-9]\d|\d[a-zA-Z-][0-9a-zA-Z-]))))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$/;

Could the groups be extracted so you the type back if you ran the regex on a string like: "1.2.3", or "1.2.3-prerelease"?

 /** @typedef {`${number}.${number}.${number}`} SemVer */ 

The second part of my comment is a value yes, but it's implicitly typed by typescript automatically. I was asking about how to use that type (and it's internals) in jsdoc.

What do you mean by this? Can you share an example?

Regular expressions do not act as type guards, and there's no way to express a type that allows one regular expression but rejects another (they're all just `RegExp`): https://www.typescriptlang.org/play/?target=5#code/MYewdgzgL...

`test()` only returns a boolean, you want to look at `exec()` which returns the result of the regular expression (typed as: `RegExpExecArray | null` which you can narrow down to `RegExpExecArray` by checking if the result is null or not).

RegExpExecArray gives you a structure that looks different between the jsdoc version and the typescript version.

The typescript version has `.groups` inside RegExpExecArray.

You can use that as is, or you can add some extra type utilities to extract the named groups from inside the regex. (If you look inside typescript's issues on github you'll find a whole bunch of them that people have wanted typescript to include by default).

There's a few regex PRs to add extraction and syntax checking to typescript by default, but they're delayed until after the compiler switch from ts to go. (but there's porting to go in the PRs anyway).

> RegExpExecArray gives you a structure that looks different between the jsdoc version and the typescript version.

> The typescript version has `.groups` inside RegExpExecArray.

The JSDoc version has `.groups` too, and it appears to be typed identically to the TypeScript version given similar configuration.

Here's the TypeScript version: https://www.typescriptlang.org/play/?target=5&strictNullChec...

And here's the JSDoc version: https://www.typescriptlang.org/play/?target=5&strictNullChec...

Could you show me what you mean in the playground? You can change it to JSDoc mode by selecting "JavaScript" in the "Lang" dropdown in the "TS Config" tab.