s/case-folding/lowercasing/

Proper Unicode case-folding absolutely does map ß to ss, ς to σ, etc. Moreover, there are some scripts (IIRC Georgian) where for historical reasons case-folding yields uppercase letters, not lowercase ones. The case-folding mapping is specifically designed in concert with the comparison rules to yield the same result, that’s why it’s a separate operation from lowercasing.

(I believe the thing described in TFA is supposed to be proper case-folding in that sense, but given TFA is AI-written I wouldn’t trust its descriptions either way.)

That said, if you want to match the sort order customary in a specific language, you need to use language-specific rules for producing collation keys rather than generic case-folding. There’s no way out of this because different users of e.g. the Latin alphabet want contradictory results. And if you think you do want generic casefolding, then you probably actually want NFKC_Casefold instead unless your input is pre-normalized.

This sounds strange given how much modern GPUs can do, but consider that a typical Windows machine ca. 2005 will have Access/JET Red, Active Directory/JET Blue, possibly MSSQL, definitely MSMQ/MTS, ODBC, OLE DB, DAO, ADO, that one SQL interpreter inside Windows Installer, and I’ve only just listed Microsoft’s database-adjacent things. I’m not surprised that press reports about the “MinWin” initiative mentioned as the main difficulty the fact that nobody could figure out if any given component was actually necessary for a Windows install to function, let alone to be compatible with third-party software. (Is anybody other than WordPad using the Word 6.0 parser included among the text converters?..) Now consider that this was, by our standards, a lightweight system on a massively underpowered computer.

Comments URL: https://news.ycombinator.com/item?id=49149414

Points: 8

# Comments: 1

When you have showdead on (as I’m guessing you do), there are weird AI-generated comments by new accounts on every front-page thread, so I wouldn’t ascribe too much significance to that part.

At least the author seems to think[1] it is one, if in not so many words:

> And don't ever let anyone tell you that Accelerando is techno-optimistic or pro-AI; by the end of the book our entire species is extinct, surviving only as simulations/memories recalled by something arguably not alive.

[1] https://news.ycombinator.com/item?id=48163630

[1] https://www.keychron.com/pages/k4-keyboard-user-manual

Standard exception handling is:

- Whenever an error happens, the program puts a description of it into an “exception” object. You go from the innermost dynamic scope to the outermost looking for handlers. Once you find a handler willing to accept that type of exception, you unwind to the point where it was installed then invoke it, passing the exception object.

Condition handling[3] is:

- Whenever an error happens, the program puts a description of it into a “condition” object. You go from the innermost dynamic scope to the outermost looking for handlers. Once you find a condition handler willing to accept that type of condition, you invoke it as a regular callback, without unwinding, passing the condition object.

- The handler then packs up some data into a “restart” object. You go through all the dynamic scopes again (remember that the erroring function is still active). Once you find a restart handling willing to accept this type of restart, you unwind to the point where it was installed then invoke it, passing the restart object.

(I am omitting things outside the happy path: a way for the exception/condition handler to punt, what happens if the condition handler does not invoke a restart, etc.)

As far as the benefits of this two-phase approach, Practical Common Lisp gives an example[4] of a single-record parser that raises an “invalid record” condition, a loop around it that installs a “skip to next record” restart, and finally the caller can make the policy decision on what to do for invalid records.

As another example, Common Lisp signals an “unbound-variable”[5] condition leaving the “use-value” and “store-value” restarts in scope, then the REPL installs a handler that offers them interactively. (My own half-serious example of a DOS abort/retry/fail prompt is in this vein too, chosen mostly because it feels strange that you can’t do it in a conventional exception system.)

[1] https://package.opendylan.org/dylan-programming-book/excepti...

[2] https://news.ycombinator.com/item?id=31196046

[3] https://www.nhplace.com/kent/Papers/Condition-Handling-2001....

[4] https://gigamonkeys.com/book/beyond-exception-handling-condi...

[5] https://www.lispworks.com/documentation/HyperSpec/Body/e_unb...

Would have been nice to hear how specifically it was made to work in the end.

> Turns out, cross-fading two 4MP images at 60 frames per second on a moderately powerful single board computer is not so easy.

Yeah, at first it feels stupid that every pretty LCD screen for bus or train stops, ads or whatnot has a full computer behind it, but then you ballpark the memory bandwidth and realize you need a ~ 1 GHz device anyway just to be able to chew through the pixels fast enough. (1920² px × 24 bpp × 60 Hz = 620 MB/s.) You also realize why “fill rate” used to be such a buzzword 20 years ago and why it took a while until true color became ubiquitous.

On the flip side of the O(n²), you can easily drive a watch-sized display with pretty good ppi using a 32-bit MCU, which is why the Apple/Google/Samsung battery-guzzling approach to smartwatches seems wrongheaded to me compared to Pebble/Zepp/etc.

Wayland: wl_shm and that’s it for the “stack”.

I think a Horizon Zero Dawn developer characterized their approach as “more realistic than reality” or something along those lines, i.e. they were aiming for the kind of perfect saturated look that you would only get in that golden hour with ideal surroundings but that we all recognize as real and at the same time don’t find too dull to stare at for hours. And I think for daytime HZD did do that quite well.

[1] https://queue.acm.org/detail.cfm?id=3703126