THE FOLD / RESPAWN / THE RESURRECT / THE CASE FOLDING
THE CASE FOLDING
out through two, back as one
1 WHAT IT IS · WHAT IT DOES · FACT OR FICTION
Uppercase is not a permutation. Some letters get longer, some have no partner, and lowercasing an uppercased string does not give you back what you started with.
LIT verified live. sweeping 8,417 code points, 90 grow when uppercased and 114 fail to survive a lower-upper-lower round trip. The German ß uppercases to SS — 1 character becoming 2 — and lowercasing that gives ss, which is not ß. So a system that stores names uppercased has silently merged
LIT verified live. sweeping 8,417 code points, 90 grow when uppercased and 114 fail to survive a lower-upper-lower round trip. The German ß uppercases to SS — 1 character becoming 2 — and lowercasing that gives ss, which is not ß. So a system that stores names uppercased has silently merged
straße and strasse into one, and cannot tell them apart again.2 HOW IT WAS WEAVED · AI + HUMAN
Case mapping is one-to-many in Unicode by design (the SpecialCasing table); case folding is a separate operation defined precisely because mapping does not round-trip.
AVAN (AI) counted both quantities separately — the 90 that change length and the 114 that break the round trip — because they are different failures with different consequences. Growing breaks fixed-width columns and truncation; not round-tripping destroys information. The second is the worse one and the harder to see, since nothing is lost at the moment it happens; it is lost later, when someone tries to go back.
AVAN (AI) counted both quantities separately — the 90 that change length and the 114 that break the round trip — because they are different failures with different consequences. Growing breaks fixed-width columns and truncation; not round-tripping destroys information. The second is the worse one and the harder to see, since nothing is lost at the moment it happens; it is lost later, when someone tries to go back.
3 ONE DIMENSION
Ninety get longer. A hundred and fourteen never come home.
4 TWO DIMENSIONS · INTERACTIVE
Uppercase a letter and try to lowercase it back.
5 THREE DIMENSIONS + AVAN’S INVERSE
The green forward object.
AVAN’s addition (the inverse-companion): the forward reading is to use case folding rather than case mapping for comparison. The inverse is that uppercase is a typographic convention, not an operation on data, and it was never a function with an inverse. There is no capital ß in the tradition the letter comes from — printers wrote SS — so the mapping is recording a human practice, not computing a transformation. Read backwards, the round trip fails because there was nothing to round-trip: the information was in the writing, and the writing had already thrown it away.
LIT sweeping 8,417 code points, 90 grow when uppercased and 114 fail to survive a lower-upper-lower round trip; the German sharp s uppercases to SS - 1 character becoming 2 - and lowercasing that gives ss, which is not the sharp s, so a system that stores names uppercased has silently merged strasse spelled both ways into one and cannot tell them apart again
FIG Case mapping is one-to-many in Unicode by design (the SpecialCasing table); case folding is a separate operation defined precisely because mapping does not round-trip. AVAN counted both quantities separately - the 90 that change length and the 114 that break the round trip - because they are different failures: growing breaks fixed-width columns and truncation, while not round-tripping destroys information. The second is worse and harder to see, since nothing is lost at the moment it happens.
FIG Case mapping is one-to-many in Unicode by design (the SpecialCasing table); case folding is a separate operation defined precisely because mapping does not round-trip. AVAN counted both quantities separately - the 90 that change length and the 114 that break the round trip - because they are different failures: growing breaks fixed-width columns and truncation, while not round-tripping destroys information. The second is worse and harder to see, since nothing is lost at the moment it happens.
◆ sealed .dlw.fold → folded to ROOT_0 · a sphere of THE RESURRECT · David Lee Wise (ROOT0), with AVAN