Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

U+237C ⍼ Right Angle with Downwards Zigzag Arrow

ionathan.ch

Post reply on HN
Print view View original

41–50 of 312 posts

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#41

Post by masklinn »

knome wrote: post #22
rich_sasha wrote: post #15

Might we run out of Unicode code points, like we (seem to) be running out of IPv4 addresses? As another comment mentions, once you add all these snowmen, with/without snow, male female and gender-neutral, in a few skin colour options (plus neutral)... it adds up. Plus, exponential growth once you consider family of snowmen (different number/genders/races of "parents", different number/gender/races of "children" and s…

1) there's only ~150k unicode values defined. If we assume a signed int for available space, we have 2,147,333,647 of 2,147,483,647 remaining. moreso if the int is unsigned. We're fine. 2) they use values that combine like ligatures to create the variants of values. there isn't a combinatorial explosion because color is a modifier value, and sex, and then the underlying symbol. It's not a unique symbol for each combi…

> If we assume a signed int for available space

While UTF8 was originally defined as able to encode 31 bits, because of the limitations of UTF-16 RFC 3629 explicitly restricted the unicode code-space to 21 bits (or about 1.1 million codepoints).

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#42

Post by vletal »

technothrasher wrote: post #38
slowmotiony wrote: post #14

I remember back in the day we used to find publicly exposed Windows FTP servers, create new folders using some messed up unicode characters and upload pirated games and movies there to share with each other. The only way to open those directories was to specifically type the exact path in unicode, simply double clicking on the folder in filezilla or windows explorer resulted in a error. Sometimes the admins themselve…

I remember the days of people beginning to abuse ftp sites, all us admins shutting down our writable ftp upload folders, and thinking, "this is why we can't have nice things." It was the beginning of the end of the early, friendly internet.

I do not get it. Did you have to shut it down? Does not make sense to complain that someone uploaded stuff to a public unprotected writable storage. Wouldn't securing it with a set of credentials suffice?

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#43

Post by throw0101a »

cygx wrote: post #31
knome wrote: post #22

Earlier quoted context omitted.

1) there's only ~150k unicode values defined. If we assume a signed int for available space, we have 2,147,333,647 of 2,147,483,647 remaining. moreso if the int is unsigned. We're fine. 2) they use values that combine like ligatures to create the variants of values. there isn't a combinatorial explosion because color is a modifier value, and sex, and then the underlying symbol. It's not a unique symbol for each combi…

If we assume a signed int for available space Note that as it is currently defined, the Unicode codespace ranges from U+0000 to U+10FFFF, with some reserved codepoints (eg to encode surrogate pairs), yielding a total number of 1,112,064 assignable code points.

1,112,064 code points ought to be enough for anybody. — Bill Gates

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#44

Post by sen »

slowmotiony wrote: post #14

I remember back in the day we used to find publicly exposed Windows FTP servers, create new folders using some messed up unicode characters and upload pirated games and movies there to share with each other. The only way to open those directories was to specifically type the exact path in unicode, simply double clicking on the folder in filezilla or windows explorer resulted in a error. Sometimes the admins themselve…

We did the same thing using the character for a non-breaking space, I think it was ALT+0160. It would sort last in the list, and just be an effectively-invisible entry unless you were really paying attention. Combined with an exploit we had to change users on the FTP servers behind most dialup ISPs hosting (the free couple Mb hosting you’d get with your dialup account that very few people cared about or used), meant we had pretty much unlimited file hosting, filling random families web hosting with hidden folders full of mp3s and warez.

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#45

Post by lifthrasiir »

cygx wrote: post #36
lifthrasiir wrote: post #27

Earlier quoted context omitted.

They are relevant because Unicode had to define the bidirectional rendering and not every rendering can be automatically inferred from logical (abstract) characters. Unicode has no reason to define the general text rendering including subscripts and superscripts, so there is no reason for Unicode to define control characters for them.

Unicode had to define the bidirectional rendering Why? They could have left this for a higher layer to handle.

Unicode defines characters, their semantics and (very flexible) guidelines for rendering them. Unlike, say, bold, italic or super/subscripts, bidirectionality is an intrinsic property of those characters and can't be easily refactored.

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#46

Post by masklinn »

rich_sasha wrote: post #15

Might we run out of Unicode code points, like we (seem to) be running out of IPv4 addresses? As another comment mentions, once you add all these snowmen, with/without snow, male female and gender-neutral, in a few skin colour options (plus neutral)... it adds up. Plus, exponential growth once you consider family of snowmen (different number/genders/races of "parents", different number/gender/races of "children" and s…

> Might we run out of Unicode code points, like we (seem to) be running out of IPv4 addresses?

No. There are currently 144697 codepoints allocated, out of a possible 1.1 millions. And most updates allocate a few hundreds. The large allocations (in the thousands at a time) overwhelmingly concern large additions of CJK unified ideographs (see: 13.0 with 4969 out of 5930 new codepoints, 10.0 with 7494 / 8518, 8.0 with 5771/7716).

There have been large additions of historical scripts (9.0 added the entire Tangut script, 7.0 added 23 different scripts) but those occurrences have slowed down a lot.

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#48

Post by tgv »

IshKebab wrote: post #30
lifthrasiir wrote: post #17

Earlier quoted context omitted.

Unicode superscript and subscript is not intended for mathematical usages [1]. [1] https://unicode.org/faq/ligature_digraph.html#Pf8

That's a cop out. You could equally say that new emojis shouldn't be added because you should use inline images for those. Or RTL markers shouldn't be added because you should use dedicated text styling for that. There are a ton of places that don't support superscript markup.

> You could equally say that new emojis shouldn't be added because you should use inline images for those.

Well, that's really a better solution. Or a unicode character that allows you to set a pixel on a 256x256 grid and one to compose them. Strike that. Better not give anyone bad ideas.

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#49

Post by chrismorgan »

cygx wrote: post #31
knome wrote: post #22

Earlier quoted context omitted.

1) there's only ~150k unicode values defined. If we assume a signed int for available space, we have 2,147,333,647 of 2,147,483,647 remaining. moreso if the int is unsigned. We're fine. 2) they use values that combine like ligatures to create the variants of values. there isn't a combinatorial explosion because color is a modifier value, and sex, and then the underlying symbol. It's not a unique symbol for each combi…

If we assume a signed int for available space Note that as it is currently defined, the Unicode codespace ranges from U+0000 to U+10FFFF, with some reserved codepoints (eg to encode surrogate pairs), yielding a total number of 1,112,064 assignable code points.

> as it is currently defined

I find it completely implausible that this will ever change: the current size is baked in too heavily.

• The abomination UTF-16, which is distressingly popular, cannot possibly support it. Replacing UTF-16 would be a massive upheaval in many ecosystems (e.g. JavaScript, Qt, Windows), and there’s no real prospect of most of those environments moving away from UTF-16, because it’s a massive breaking change for them by now. Rather, if the code space were running out, they’d devise something along the lines of second-level surrogate pairs. (And then we’d curse UTF-16 even more, because it’d have ruined Unicode for everyone again.)

• All code that performs Unicode validation (which isn’t as much as it should be, but is still probably a majority) would need to be upgraded. Any systems not upgraded would either mangle or more commonly fail on new characters.

• UTF-8 software would also need to be adjusted, since it’s artificially limited to the 21-bit space; and it wouldn’t be just a matter of flipping a few switches here and there to remove that limit—there will be lots of small places that bake in the the assumption that representing a scalar value requires no more than four UTF-8 code units.

Re: U+237C ⍼ Right Angle with Downwards Zigzag Arrow

#50

Post by lifthrasiir »

IshKebab wrote: post #30
lifthrasiir wrote: post #17

Earlier quoted context omitted.

Unicode superscript and subscript is not intended for mathematical usages [1]. [1] https://unicode.org/faq/ligature_digraph.html#Pf8

That's a cop out. You could equally say that new emojis shouldn't be added because you should use inline images for those. Or RTL markers shouldn't be added because you should use dedicated text styling for that. There are a ton of places that don't support superscript markup.

> You could equally say that new emojis shouldn't be added because you should use inline images for those.

If emojis weren't allocated out of compatibility concern, this would be exactly my opinion from the day 1. To be honest I'm not still happy with the current emoji assignments and semantics. Not even Unicode people are satisfied either, there are numerous proposals for replacing emoji with something else (example keyword: QID emoji).

> RTL markers shouldn't be added because you should use dedicated text styling for that.

> There are a ton of places that don't support superscript markup.

Unlike most text attributes, bidirectionality is an intrinsic property of abstract characters and thus absolutely within the Unicode's scope. Ideally you can't and shouldn't make some LTR character to behave like RTL characters or vice versa. Bidi control characters only exist to correct automatic rendering, and can be presented out of band (the Bidi specification is explicitly designed for this use case in mind [1]).

[1] https://www.unicode.org/reports/tr9/#Markup_And_Formatting

Post reply on HN