Look-behind proposal

Jason Orendorff jason.orendorff at gmail.com
Mon May 18 21:53:18 UTC 2015


On Mon, May 18, 2015 at 1:51 PM, Claude Pache <claude.pache at gmail.com> wrote:
> Another more powerful approach (which I prefer), [...]

As long as we prohibit matching groups within lookbehind assertions, I
think the approach you prefer is a strict superset of what's proposed.
So there's no opportunity cost to taking the proposal as-is: the .NET
semantics could be compatibly added later.

I imagine TC39 gives some preference to proposals that exist in a
concrete form. So if you prefer the .NET approach enough to do
anything about it, now's a great time to write some spec text.

> That said, I think there are easier missing features to be added, that are
> supported by most other RegExp flavours. I'm thinking of:
>
> * the `s`, or `.dotall` flag: the dot `.` matches every character, including
> newlines;
> * true support of Unicode, namely: escape sequences such as `\Lu` for
> uppercase letter, or `\X` for grapheme cluster.

Why not submit proposals for these?

-j


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