find: use slash or pipe in sed-like command

[Exirel]

Description

Attempted fix for #1188

So it was kind of messy because working with backreference to negate them is (not) surprisingly hard to do. I got some help from StackOverflow but I had to let go of the "you can escape the separator to use it inside the substitution/editing text ".

But heh, on the other hand, as one of the authors of the previous regex, if you want both / and | as separator AND having both in a substitution message:

you're shit out of luck because this is the fucking regex of death as it is.

PS: it was on @dgw 's task list, but I did it anyway out of curiosity for regex backreference.

Checklist

• I have read CONTRIBUTING.md
• I can and do license this contribution under the EFLv2
• No issues are reported by make qa (runs make quality and make test)
• I have tested the functionality of the things this change touches

[dgw]

I unlinked #1188 because that requests support for using any character as delimiter; this PR adds only one alternative, and removes the escaping feature.

This might get skipped for 7.1, not sure. I'd like to experiment with lookarounds for handling escapes, and/or libraries like sedparse that could be used after this plugin gets extracted to its own package in the run-up to Sopel 8 (since we're conservative about dependencies primarily so no one has to install the whole universe even if they disable the whole core set).

[Exirel]

This might get skipped for 7.1, not sure. I'd like to experiment with lookarounds for handling escapes

Works for me, either way I gave it a shot!

[dgw]

I'll hold on an approving review for now, but everything is addressed. I just have to do that lookaround research/experiment(s) and/or decide if this is worth breaking the escaped-delimiter feature in a point release.

[dgw]

@Exirel Were you thinking of simplifying this to the easier solution of two rules? Though I still want to investigate lookarounds.

[Exirel]

@dgw updated, see if you like it better. Escaping is back!

[dgw]

I actually like this approach a lot. It just looks like there might be a little mistake in one of the rules?

[Exirel]

Should be better now.

[dgw]

Here we can see why this was deemed "the fucking regex of death" at one point. Pattern's so long you get lost in it! 😂

[dgw]

Yep, this looks ready to squash out the fixups 🚀