Deprecate String#codepoint_at

[vlazar]

Ref #8449

I'm not sure if the use of String#codepoint_at should be removed in this PR or in follow-up PR where String#codepoint_at is removed.

I see some other deprecation warnings when running crystal specs, so I assume it may be intentional and serves as a reminder to remove usage later when the method itself is removed.

Let me know if String#codepoint_at usage should be removed in this PR.

[straight-shoota]

Deprecated methods should not be used, so please remove its uses in stdlib.

But they continue to be tested in the spec suite, that's where the warnings come from (see discussion in #8454).

[vlazar]

@straight-shoota Sorry, I'm confused now. By stdlib do you mean only the src/ excluding spec/?

The only usage is currently in specs, and those specs are not for codepoint_at itself, it's just that it's being used for testing.

From #8454 (comment)

I prefer a CI with warnings rather than untested deprecated methods. But If I'm the only one who thinks that way, we can go ahead.

So should I remove the usage of codepoint_at from specs in this PR?

[straight-shoota]

Oh sry, I was under the impression there was a single "real" use somewhere in stdlib.

By stdlib do you mean only the src/ excluding spec/?

Well, essentially all uses except those where specifically this method is tested should be removed. In this case, there are none. But "escapes with unicode" acts as such, so I guess we should leave it for now and only change that with #8476.

[asterite]

I'm still not sure why we removed this...

[vlazar]

No real world usage as described in the original issue #8449?

I could only find two real usages of this method in markd, while looking all of GitHub's Crystal repositories.

[asterite]

I think the number of actual usages don't matter. Crystal is not a hugely popular language. It's good to have the option to easly get a codepoint of a char. That's what makes Ruby great, the many shortcuts you have to things, to avoid boilerplate code or doing many hoops. But if others think removing this was fine then it's fine.

[vlazar]

It's not late yet to revert before the release.

[straight-shoota]

@asterite Useful shortcuts are great. But codepoint_at(index) doesn't provide a huge benefit over char_at(index).ord. If we follow the discussion from #8449 and rename ord to codepoint, it would at least be a bit shorter, but still not provide a simplification in terms of reducing boilerplate etc.
So you have two ways to do the exact same thing and they are largely identical from a user perspective. Per this argument we try to avoid aliases, and this is essentially the same thing. Removing this method doesn't remove any features because there's an equivalent alternative. But it's one less feature to learn.