Implement lookaround

[mdinger]

• lookahead - foo <?after bar> matches foo in foobar
• negative lookahead - foo <!after bar> matches foo in foobaz
• lookbehind - <?before foo> bar matches bar in foobar
• negative lookbehind - <!before foo> bar matches bar in sushibar

An example with both: <?before foo> bar <?after baz> matches bar in foobarbaz

This is different from Perl 6 as noted in perl_changes and is subject to change. I'll need to get experience using it and then compare. Perl 6 may have gotten it correct but I'm not sure or convinced. Granted, I don't think deviating from Perl 6 shouldn't be taken lightly.

I have a PR for this but it doesn't work correctly and I have to do a major revision. Not sure when I'll get to it.

[olorin37]

It would be great to propagate raku / perl6 regexes to other languages and Rust seems good for the beginning...

[mdinger]

I have not worked on this for a very long time and currently have no plans to currently. If someone decides to start working on this, I can add them as a collaborator or something similar so they can start doing cool things with it.

[olorin37]

Yep it would be nice to have it, but I also could not find time for such project currently... Pozdrawiam, Jakub A. Gramsz

…

________________________________ From: mdinger ***@***.***> Sent: Friday, December 10, 2021 11:37:40 PM To: mdinger/rules ***@***.***> Cc: Jakub A. G. ***@***.***>; Comment ***@***.***> Subject: Re: [mdinger/rules] Implement lookaround (#1) I have not worked on this for a very long time and currently have no plans to currently. If someone decides to start working on this, I can add them as a collaborator or something similar so they can start doing cool things with it. — You are receiving this because you commented. Reply to this email directly, view it on GitHub<#1 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABNIB5JZOLDOFCUAEVNVDLDUQJ6LJANCNFSM4BPYSDPQ>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.