[ refactor ] ScopedSnocList: Preparing for the long jump (Phase 1)

[GulinSS]

Core idea is to split the process of transition from List-based Scope on SnocList-based Scope on 2 phases:

1. Apply a refactor which does not make any transition (even no observable changes for Idris users) actually but prepare the code for future update.
2. Roll out the transition with limited code changes invasion because it was partially done at the step before.

[gallais]

Thanks for that.

FYI we (including at least @mjustus & me) are planning to do a big code review
on this PR on April 2nd with the hope it can quickly be merged afterwards.

[GulinSS]

@gallais much appreciate! 😇

[GulinSS]

@gallais, @mjustus shy reminder about the review and its importance! 🙏

We are going to make further steps of adding parts from Yaffle when this PR and its companion will succeed.

All this is a refactor which is important but these steps actually are preparations for something which can be added to the change log . And this step is scheduled to start the development after these 2 phases.

So, moving forward here is a corner stone to unlock further Idris improvements. All this is clear for invited people just it seemed important to explicitly emphasize at the message due of questions at Discord group.

[gallais]

We went through about a 3rd of the files. There a semantic issues (e.g. some lists of values being
made Scopeable even though they have nothing to do with Scopes) and we wanted to clarify some
things outside of the diff boundaries so started a fork of the fork.

[GulinSS]

@gallais any news would be very appreciate! We are in progress of porting other parts from Yaffle and pretty worried of possible changes 😅

It would be nice if you can put a link to PR/commits/branch/anything where we might participate during the review process. If it is needed of course.

[gallais]

Ping @mjustus

We haven't had the opportunity to have another meeting yet. And with
a conference happening this week it may not happen for another couple
of weeks either.

[GulinSS]

Pinned for watching: https://github.com/mjustus/Idris2/tree/scoped-snoc-list-preparing-review

[gallais]

We met up today (thanks Justus for your hospitality!) and we've made good progress.
We have looked at about 75/103 files meaning we should be done by the end of our
next meeting in 2 weeks time.

[mjustus]

I have pushed your current state to branch snoc-list-preparing-force-pushed on my copy of the repository and am about to revert this branch to f7bc725 because it was getting too difficult reviewing a moving target with large merge conflict.