Proposing new arrow characters with Bidi_Mirrored=Yes

[NeatNit]

On Tuesday, 8 April 2025 at 21:48, Mark E. Shoulson via Unicode <unicode at corp.unicode.org> wrote:

> (The above quoted-quotes from Asmus)
>
> (this quoted-quote is from me)

I'm still getting the hang of mailing lists. Not even sure whether to use plain text or rich text. Thanks for your patience :) I'll be sure to include the quote header from now on. Is it overdoing it to include it on every individual quote? Hmm...

On Tuesday, 8 April 2025 at 21:48, Mark E. Shoulson via Unicode <unicode at corp.unicode.org> wrote:

> Ah! OK, now we're talking. I see the use case. I haven't read details on the software in question, but I take it the point is that you're presenting a route and there's a list of waypoints and it's presented as "And now go from point A → point B" and needs to be localized/internationalized. This actually... sounds like a reasonable use? I mean, it makes sense why this wouldn't be served by the current situation and why people would want something smarter.

Yes! This is exactly the type of thing I'm talking about, mirroring arrows are needed for internationalization. Thanks for expressing it better than I apparently did.

To be pedantic, while the example you gave of "point A → point B" is a valid one, it's not the one shown in those first two examples. Those examples show a diff after someone edited data. The arrow shows: old value → updated value.

In the first issue I linked, I suggested replacing the arrow with U+22B6 ⊶ Original Of, which is a mirroring character, but this suggestion was not taken, or perhaps they didn't see it. Regardless, if the aesthetic they want is an arrow, Unicode shouldn't force them to use a different visual instead just to get the required behavior.

> Now that I see your intended situation, I think what I was imagining would not, in fact, help you. [...]

I thought not, but the modifier idea is way better. I am aware of the various directional overrides, and the much more useful directional markers and isolators. Not really sure when overrides are useful, but I'm sure there are some cases - if nothing else, it's useful for English speakers to test bidi unicode behavior!

> > I actually love that idea! It would solve the issue for all arrows (and any other glyphs in ExtraMirroring.txt), while only introducing one or two new code point. Maybe also <NON MIRRORED SELECTOR> to disable mirroring even on character with Bidi_Mirroring=Yes.
> 
> And this would work better, if we take it to mean "the character this is attached to is _subject_ to mirroring."

Exactly, thank you for making that clearer. "The character is subject to mirroring" is precisely what's needed.

> But markup-type characters in Unicode are a grey area and those which exist are not widely loved either. As Marcus Scherer writes: [...]

Well, lessons you guys have learned in the past is something I'm obviously not going to know. I do believe this kind of control character is a great idea. It's a choice between the control character, the near-duplicate characters, or leaving this use-case unfulfilled. Obviously I don't want the last option, and duplicate characters have their obvious downsides as previously discussed. I don't see any obvious downside to your proposed control character, besides general wariness.

> > > I don't even want to know about handling this in TTB contexts...
> > 
> > What is TTB? Couldn't quickly find it.
> 
> Top-To-Bottom. Vertical text. Just one more way for things to be confused.

Oh. Well, at least there's not Bottom-To-Top also, right?

... right?

- Nitai