support mark-(next|previous)-like-this

[Prikaz98]

There is a similar PR, but I didn't use isearch to find the next marks.

mark-(next|previous)-like-this aims to work like multiple-cursors.el This means that if there is nothing to select, it marks the next or previous line.
Handling offsets is a bit complex because we need to maintain the same starting or ending position of the region when calling mark-next or mark-prev.

Demo:

TODO:

• Figure out how to write the test
• Fix the bug where duplicate marks appear when spamming the commands add-cursors-to-(next|prev)-line (previously handled by clear-duplicate-cursors; I believe we can address this within the function that determines the next cursor position)

[Prikaz98]

Also added C-g double click behavior (first cancel mark region, second clean multicursors)

[Prikaz98]

I have a problem with test running. I read an instruction from this page
and checked rove project but unfortunately I've got the same result.
Or this

.qlot/bin/rove lem-tests.asd

Testing System lem-tests

✓ 0 tests completed

Summary:
  All 0 tests passed.

no test executed

or

.qlot/bin/rove tests/cursors.lisp

Unhandled ASDF/FIND-COMPONENT:MISSING-COMPONENT in thread #<SB-THREAD:THREAD tid=1070475 "main thread" RUNNING
                                                             {1003F80003}>:
  Component "lem-tests/cursors" not found

If someone know what is wrong, please let me know 🙏

I saw your like:) Can you help me pls @cxxxr

[cxxxr]

lem-tests is not a package-inferred-system, so it is not possible to run tests on a file-by-file basis from rove.
If you want to test individually, how about running 'run-test' from the REPL?

[Prikaz98]

I think that's enough for this PR. If you see any issues in my code, feel free to leave comments :)

[cxxxr]

Thank you for the PR.
I'm checking the behavior now.
This looks similar to

lem/src/ext/isearch.lisp

Line 90 in 34126e5

(define-key *isearch-keymap* "C-M-n" 'isearch-add-cursor-to-next-match)

but is it different?

[Prikaz98]

Oh, yes, it is a similar function. I didn't know that this function already exists in isearch module. Let's close this PR and I just keep it in my personal build.

Also it will be great to add mention in Lem doc in multiple cursors description. Because when I read it I thought: "Oh, there is no my most useful function mc mode. I must implement this"

[cxxxr]

Yeah, I'm sorry there are no documents. That's something we need to improve.
Also, since the functions of isearch are incomplete, I would be happy if they could be integrated with this PR.

[Prikaz98]

Merged prior changes with the existing implementation in the isearch module. Hopefully, it turned out pretty nice.

[cxxxr]

Thank you so much!
it can't support the behavior of having multiple cursors on the same line that was supported before this change, but I will merge this PR itself.