[arp242]

> so the idea of a world with only precomposed letter forms is more of a exponential explosion in the character set

"Exponential explosion" is really putting it too strong; it's perfectly possible to just add ǿ and á̤ and a bunch of other things. The combinations aren't infinite here.

The problem with e.g. Latin script isn't necessarily that combining characters exist, but that there's two ways to represent many things. That really is just a "mess": use either one system or the other, but not both. Hangul has similar problems.

Devanagari doesn't have any pre-compose characters AFAIK, so that's fine.

That's really the "mess": it's a hodgepodge of different systems, and you can't even know which system to use a lot of the time because it's not organised ("look it up in a large database"), and even taking in to account historical legacy I don't think it really needed to be like this (or is even an unfixable problem today, strictly speaking).

At least they deprecated ligatures like st and fl, although recently I did see ij being used in the wild.

[WorldMaker]

> The combinations aren't infinite here.

They certainly are. Languages are a creative space driven by the human imagination. Give people enough time and they'll build new combinations for fun or for profit or for research or for trying to capture a spoken word/tone poem in just the right sort of exciting way. You may frown on "Zalgo text" [1] (and it is terrible for accessibility), but it speaks to a creative mood or three.

The growing combinatorial explosion in Unicode's emoji space isn't an accident or something unique to emoji, but a characteristic that emoji are just as much a creative language as everything else Unicode encodes. The biggest difference is that it is a living language with a lot of visible creative work happening in contemporary writing as opposed to a language some monks centuries ago decided was "good enough" and school teachers long ago locked some of the creative tools in the figurative closets to keep their curriculum simpler and their days with fewer headaches.

[1] https://en.wikipedia.org/wiki/Zalgo_text

[arp242]

Well, in theory it's infinite, but in reality it's not of course.

We've got 150K assigned codepoints assigned, leaving us with 950K unassigned codepoints. There's truly massive amounts of headroom.

To be honest I think this argument is rather too abstract to be of any real use: if it's a theoretical problem that will never occur in reality then all I can say is: <shrug-emoji>.

But like I said: I'm not "against" combining marks, purely in principle it's probably better, I'm mostly against two systems co-existing. In reality it's too late to change the world to decomposed (for Latin, Cyrillic, some others) because most text already is pre-composed, so we should go full-in on pre-composed for those. With our 950k unassigned codepoints we've got space for literally thousands of years to come.

Also this is a problem that's inherent in computers: on paper you can write anything, but computers necessarily restrict that creativity. If I want to propose something like a "%" mark on top of the "e" to indicate, I don't know, something, then I can't do that regardless of whether combining characters are used, never mind entirely new characters or marks. Unicode won't add it until it sees usage, so this gives us a bit of a catch-22 with the only option being mucking about with special fonts that use private-use (hoping it won't conflict with something else).

[WorldMaker]

The Unicode committees have addressed this for languages such as Latin, Cyrillic, and others and stated outright that decomposed forms should be preferred and decomposition canonical forms are generally the safest for interoperability and operations such as collation (sorting) and case folding (lowercase to uppercase transformations).

Unicode can't get rid of the many precombined characters for a huge number of backward compatibility reasons (including compatibility with ancient Mainframe encodings such as EBCDIC which existed before computer fonts had ligature support), but they've certainly done what they can to suggest the "normal" forms in this decade should "prefer" the decomposed combinations.

> If I want to propose something like a "%" mark on top of the "e" to indicate, I don't know, something, then I can't do that regardless of whether combining characters are used

This is where emoji as a living language actually shines a living example: It's certainly possible to encode your mark today as a ZWJ sequence, say «e ZWJ %», though you might want to consider for further disambiguation/intent-marking adding a non-emoji variation selector such as Variation Selector 1 (U+FE00) to mark it as "Basic Latin"-like or "Mathematical Symbol"-like. You can probably get away with prototyping that in a font stack of your choosing using simple ligature tools (no need for private-use encodings). A ZWJ sequence like that in theory doesn't even "need" to ever be standardized in Unicode if you are okay with the visual fallback to something like "e%" in fonts following Unicode standard fallback (and maybe a lot of applications confused by the non-recommended grapheme cluster). That said, because of emoji the process for filing new proposals for "Recommended ZWJ Sequences" is among the simplest Unicode proposals you can make. It's not entirely as Catch-22 on "needs to have seen enough usage in written documents" as some of the other encoding proposals.

Of course, all of that is theory and practice is always weirder and harder than theory. Unicode encoding truly living languages like emoji is a blessing and it does enable language "creativity" that was missing for a couple of decades in Unicode processes and thinking.

[arp242]

> The Unicode committees have addressed this for languages such as Latin, Cyrillic, and others and stated outright that decomposed forms should be preferred

Yes, and that only makes things worse since the overwhelming majority of documents (99.something% last time I checked) uses pre-composed. Also AFAIK just about everyone just ignores that recommendation.

This is a classic "reality should adjust to the standard" type of thinking. Previous comments about that: https://news.ycombinator.com/item?id=36984331

I suppose "e ZWJ %" is a bit better than Private Use as it will appear as "e%" if you don't have font support, but the fundamental problem of "won't work unless you spend effort" remains. For a specific niche (math, language study, something else) that's okay, but for "casual" usage: not so much. "Ship font with the document" like PDF and webfonts do is an option, but also has downsides and won't work in a lot of contexts, and still requires extra effort from the author.

I'm not saying it's completely impossible, but certainly harder than it used to be, arguably much harder. I could coin a new word right here and now (although my imagination is failing me to provide a humorous example at this moment) and if people like it, it will see usage. In 1960s HN when we would have exchanged these things over written letters, and it would have been trivial to propose a "e with % on top" too, but now we need to resort to clunky phrases like this (even for typewriters you can manually amend things, if you really wanted to).

Or let me put it this way: something like ‽ would see very little chance of being added to Unicode if it was coined today. Granted, it doesn't see that much use, but I do encounter it in the wild on occasion and some people like it (I personally don't actually, but I don't want to prevent other people from using it).

None of this is Unicode's fault by the way, or at least not directly – this is a generic limitation of computers.

[WorldMaker]

> Yes, and that only makes things worse since the overwhelming majority of documents (99.something% last time I checked) uses pre-composed.

It shouldn't matter what's in the wild in documents. That's why we have normalization algorithms and normalization forms. Unicode was built for the ugly reality of backwards compatibility and that you can't control how people in the past wrote. These precomposed characters largely predate Unicode and were a problem before Unicode. Unicode won in part because it met other encodings where they were rather than where they wished they would be. It made sure that mappings from older encodings could be (mostly) one-to-one with respect to code points in the original. It didn't quite achieve that in some cases, but it did for, say, all of EBCDIC.

Unicode was never in the position to fix the past, they had to live with that.

> This is a classic "reality should adjust to the standard" type of thinking.

Not really. The Unicode standard suggests the normal/canonical forms and very well documented algorithms (including directly in source code in the Unicode committee-maintained/approved ICU libraries) to take everything seen in the wilds of reality and convert them to a normal form. It's not asking reality to adjust to the standard, it is asking developers to adjust to the algorithms for cleanly dealing with the ugly reality.

> Or let me put it this way: something like ‽ would see very little chance of being added to Unicode if it was coined today.

Posted to HN several times has been the well documented proposal process from start to finish (it succeeded) of getting common and somewhat less common power symbols encoded in Unicode. It's a committee process. It certainly takes committee time. But it isn't "impossible" to navigate and is certainly higher than "little chance" if you've got the gumption to document what you want to see encoded and push the proposal through the committee process.

Certainly the Unicode committee picked up a reputation for being hard to work with in the early oughts when the consortium was still fighting the internal battles over UCS-2 being "good enough" and had concerns about opening the "Astral Plane". Now that the astral plane is open and UTF-16 exists, the committee's attitude is considered to be much better, even if its reputation hasn't yet shifted from those bad old days.

> None of this is Unicode's fault by the way, or at least not directly – this is a generic limitation of computers.

Computers do anything we program them to do and in general people find a way regardless of the restrictions and creative limitations that get programmed. I've seen MS Paint drawn symbols embedded in Word documents because the author couldn't find the symbol they needed or it didn't quite exist. It's hard to use such creative problem solving in HN's text boxes, but that from some viewpoints is just as much a creative deficiency in HN's design. It's not an "inherent" problem to computers. When it is a problem they pay us software developers to fix it. (If we need to fix it by writing a proposal to a standards committee such as the Unicode Consortium, that is in our power and one of our rights as developers. Standards don't just bind in one-direction, they also form an agreement of cooperation in the other.)

[arp242]

The thing with normalization is that it's not free, and especially for embedded use cases people seem quite opposed to this. IIRC it requires about ~100K of binary size, ~20K of memory, and some non-zero number of CPU cycles. This is negligible for your desktop computer, but for embedded use cases this matters (or so I've been told).

This comes up in specifications that have a broad range of use cases; when I was involved in this my idea was to just spec things so that there's only one allowed form; you'll still need a small-ish table for this, but that's fine. But that's currently hard because for a few newer Latin-adjacent alphabets some letters cannot be represented without a combining character.

So then you have either the "accept that two things which seem visually similar are not identical" (meh) or "exclude embedded use cases" (meh).

I never really found a good way to unify these use cases. I've seen this come up a few times in various contexts over the years.

> Posted to HN several times has been the well documented proposal process from start to finish (it succeeded) of getting common and somewhat less common power symbols encoded in Unicode.

Would this work for an entirely new symbol I invent today? It's not really the Unicode people that are "difficult" here as such, they just ask for demonstrated usage, which is entirely reasonable, and that's hard to get (or: harder than it was before computers) especially for casual usage. I'm sure that if some country adopts/invents a new script today, as seems to be happening in West-Africa at in recent years, the Unicode people are more than amendable to work with that, but "I just like ‽" is a rather different type of thing.