Added more unicode sub/superscripts to Latex tab completions

[lstagner]

This is an addition to pr #6927. This adds a full superscript Latin lowercase alphabet except q ( ᵃ ᵇ ᶜ ᵈ ᵉ ᶠ ᵍ ʰ ⁱ ʲ ᵏ ˡ ᵐ ⁿ ᵒ ᵖ ʳ ˢ ᵗ ᵘ ᵛ ʷ ˣ ʸ ᶻ ), a limited uppercase Latin alphabet ( ᴬ ᴮ ᴰ ᴱ ᴳ ᴴ ᴵ ᴶ ᴷ ᴸ ᴹ ᴺ ᴼ ᴾ ᴿ ᵀ ᵁ ⱽ ᵂ ), a few subscripted lowercase Latin letters ( ₐ ₑ ₕ ᵢ ⱼ ₖ ₗ ₘ ₙ ₒ ₚ ᵣ ₛ ₜ ᵤ ᵥ ₓ ), and some Greek letters ( ᵅ ᵝ ᵞ ᵟ ᵋ ᶿ ᶥ ᶲ ᵠ ᵡ ᵦ ᵧ ᵨ ᵩ ᵪ ).

[stevengj]

Seems fine to me.

[kmsquire]

Just to ask the obvious, since I haven't been part of these discussions: why is it that some of the letters can't be represented? \^q doesn't seem to map to anything in my REPL.

[lstagner]

@kmsquire Its a matter of what is available in unicode. If you can find a unicode superscript q I welcome the addition.

[stevengj]

See this discussion on Unicode q superscripts. Useful quote:

Members of the UTC sometimes let a-priori prejudices get in the way of wisdom. We saw this before the disunification of Coptic from Greek, and Ecclesiastical Georgian from standard Georgian. We still see it in a number of areas: it's a battle to encode any punctuation, any symbol (unless backed by a Japanese telco), borrowings between Latin, Cyrillic, and Greek.

If we have nearly all of the basic Latin alphabet available as superscript letters it is perverse not just to complete the set. What's more perverse is that sometimes it's agreed to add characters in order to complete sets, but other times barriers are put up against doing so. Unfortunately, the UTC has never been consistent. I know this, because I've had both kinds of answer from them so often it makes my head spin. It's no wonder this causes frustration, which causes push-back, which causes bad feelings, which causes bad relations.

[lstagner]

This Unicode Technical Note "UNICODE NEARLY PLAIN-TEXT ENCODING OF MATHEMATICS" might be a good resource for the future

[kmsquire]

@lstagner, @stevengj, thanks! I was actually surprised to see that any alphabetic letters existed as super- or subscripts.

I suspect that others will have the same question if using these becomes popular.

[stevengj]

Not all of these seem to be supported in identifiers yet:

julia> aₙ = 3
ERROR: syntax: invalid character "ₙ"

[JeffBezanson]

This is in category Lm, which is allowed for identifiers. However utf8proc seems not to know about this character, or has some bug in its tables.

[JeffBezanson]

Ah, that character was added in unicode 6.0.0, and the latest utf8proc only supports 5.0.0.

[stevengj]

I've created a github repo to work on a proposal for more sub/superscripts, to be submitted to Unicode: https://github.com/stevengj/subsuper-proposal

Comments/contributions are welcome.

[tkelman]

Great! I wasn't joking in #18139 (comment). Worked for http://unicodepowersymbol.com.