4 ms·

Rot8000 – Rot13 for the Unicode generation

47 points by rottytooth 13y ago

jloughry 13y ago
Why not call it Rot8192 or Rot0x7777 ?
- throwaway0094 13y ago
  rot13 is (X + (26/2)) mod 26 ; this is (X + (2^16)/2) mod 2^16. (The BMP is the first 2^16 code points of unicode.) Edit: silly formatting dropped my math punctuation.
  - CUViper 13y ago
    I suspect they also really wanted the rot8 -> "rotate" joke. AFAICS, it's actually using decimal 8000, not 2^16/2 = 0x8000, so I don't really understand how this is reversible at all unless they're just subtracting it back. What we really need is rot88000h for the full U+0..U+10FFFF range. :)
    - rottytooth 13y ago
      It's using 0x8000, which is half of 0x10000 (the size of the basic multilingual plane). It doesn't extend out of BMP
mischanix 13y ago
Not reciprocal for CJK input, e.g. "한글" takes 5 iterations to reach stability. I believe this has to do with the utf-16 encoding of codepoints > 0x10000
- lelf 13y ago
  한글 is in basic plane. It's U+D55C U+AE00
  - rottytooth 13y ago
    Something might be off in the math -- there are some work-arounds to skip control characters that might be off when starting in this range
  - mischanix 13y ago
    I was considering the fact that when it adds 0x8000 or whatever it's doing it's hitting 0x1.... codepoints and doing weird things with those because of the encoding. Here's a trace of 한글 through this 'rot8000', though: 한글: 0xd55c 0xae00 똼軠: 0xb63c 0x8ee0 霜激: 0x971c 0x6fc0 矼傠: 0x77fc 0x50a0 壜ㆀ: 0x58dc 0x3180 㦼በ: 0x39bc 0x1260 ᪜ㆀ: 0x1a9c 0x3180 㦼በ: (repeating) So... yeah. Weirdness all around. Might have better luck doing this with some carefully crafted xor pad for each codepoint so that it's likely to hit a printable character but impossible to hit a character in the 0xD800..0xDFFF range (and similar ranges)... trying to "wrap" in unicode would require reinterpreting the codepoints to some continuous numeric representation.
lelf 13y ago
It's broken. Λ̊1 → ⊻∪ά → Λ̊⋌ 𝄞 → 뤔뷾 → 駴點 Edit: anyway, even with correct (a+b)%n it's plain bad idea. Unicode is not English alphabet. Everything not in basic multilingual plane is broken automatically. And even in BMP there's going to be bag of glitches starting from hanging combining characters and ending to ‘oops someone normalised our string and it's now different’ (for site, not for user / Unicode).
- bouk 13y ago
  Pretty sure it's meant as a joke
  - rottytooth 13y ago
    It is meant as a joke -- but also planning to fix these issues ... apparently this was the right place to bring it to find all the situations where it doesn't work correctly :)
    - derefr 13y ago
      Rather than rotating through the entire BMP, I would suggest instead using Unicode's localized collations, and just rotating every character that's part of a fully-orderable "alphabet" set through that set according to those orders. (This means, for example, rotating Japanese hiragana, but not kanji.)
- rottytooth 13y ago
  CJK support is fixed now.
peterwaller 13y ago
Copy-pasting the contents of rot8000.com/info in and hitting cypher twice ends up scrambling the contents quite a bit.. It also bypasses 32 control characters, technically making it rot7968, sometimes with an additional offset. -> It also bypasses ⋍2 control characters, technically making it rot⋏⋬68, sometimes with an additional offset.
- rottytooth 13y ago
  hmm, I'm not seeing this result
aculver 13y ago
Inputting "こんにちは。元気ですか？" caused an application error: [ArgumentException: Error serializing value 'ᄳᅳᅋᅁᅏტ㈣䳷ᅇᄹᄫ�' of type 'System.String.'] After realizing it was "？" that was breaking everything, I ended up with this round trip: "こんにちは。元気ですか。" → "ᄳᅳᅋᅁᅏტ㈣䳷ᅇᄹᄫტ" → "こんにちは。ጃ⷗ですか。" It's broken. I suspect Unicode requires more careful manipulation than OP anticipated. :-)
deleted 13y ago
[deleted]
njharman 13y ago
I just realized that 13 was probably chosen for rot13 cause that's half the number of letters in English alphabet. I miss "obvious" stuff like that all the time.
rottytooth 13y ago
I put in a fix for CJK and the result is: nearly everything that's not CJK now rotates into it and back out; CJK is an huge section of the Basic Multilingual Plane. The fix invalidates rotations done with rot8000 before the fix, unfortunately.

47 points by rottytooth 13y ago

jloughry 13y ago

Why not call it Rot8192 or Rot0x7777 ?

throwaway0094 13y ago
rot13 is (X + (26/2)) mod 26 ; this is (X + (2^16)/2) mod 2^16. (The BMP is the first 2^16 code points of unicode.) Edit: silly formatting dropped my math punctuation.
- CUViper 13y ago
  I suspect they also really wanted the rot8 -> "rotate" joke. AFAICS, it's actually using decimal 8000, not 2^16/2 = 0x8000, so I don't really understand how this is reversible at all unless they're just subtracting it back. What we really need is rot88000h for the full U+0..U+10FFFF range. :)
  - rottytooth 13y ago
    It's using 0x8000, which is half of 0x10000 (the size of the basic multilingual plane). It doesn't extend out of BMP

mischanix 13y ago

Not reciprocal for CJK input, e.g. "한글" takes 5 iterations to reach stability. I believe this has to do with the utf-16 encoding of codepoints > 0x10000

lelf 13y ago
한글 is in basic plane. It's U+D55C U+AE00
- rottytooth 13y ago
  Something might be off in the math -- there are some work-arounds to skip control characters that might be off when starting in this range
- mischanix 13y ago
  I was considering the fact that when it adds 0x8000 or whatever it's doing it's hitting 0x1.... codepoints and doing weird things with those because of the encoding. Here's a trace of 한글 through this 'rot8000', though: 한글: 0xd55c 0xae00 똼軠: 0xb63c 0x8ee0 霜激: 0x971c 0x6fc0 矼傠: 0x77fc 0x50a0 壜ㆀ: 0x58dc 0x3180 㦼በ: 0x39bc 0x1260 ᪜ㆀ: 0x1a9c 0x3180 㦼በ: (repeating) So... yeah. Weirdness all around. Might have better luck doing this with some carefully crafted xor pad for each codepoint so that it's likely to hit a printable character but impossible to hit a character in the 0xD800..0xDFFF range (and similar ranges)... trying to "wrap" in unicode would require reinterpreting the codepoints to some continuous numeric representation.

lelf 13y ago

It's broken. Λ̊1 → ⊻∪ά → Λ̊⋌ 𝄞 → 뤔뷾 → 駴點 Edit: anyway, even with correct (a+b)%n it's plain bad idea. Unicode is not English alphabet. Everything not in basic multilingual plane is broken automatically. And even in BMP there's going to be bag of glitches starting from hanging combining characters and ending to ‘oops someone normalised our string and it's now different’ (for site, not for user / Unicode).

bouk 13y ago
Pretty sure it's meant as a joke
- rottytooth 13y ago
  It is meant as a joke -- but also planning to fix these issues ... apparently this was the right place to bring it to find all the situations where it doesn't work correctly :)
  - derefr 13y ago
    Rather than rotating through the entire BMP, I would suggest instead using Unicode's localized collations, and just rotating every character that's part of a fully-orderable "alphabet" set through that set according to those orders. (This means, for example, rotating Japanese hiragana, but not kanji.)
rottytooth 13y ago
CJK support is fixed now.

peterwaller 13y ago

Copy-pasting the contents of rot8000.com/info in and hitting cypher twice ends up scrambling the contents quite a bit.. It also bypasses 32 control characters, technically making it rot7968, sometimes with an additional offset. -> It also bypasses ⋍2 control characters, technically making it rot⋏⋬68, sometimes with an additional offset.

rottytooth 13y ago
hmm, I'm not seeing this result

aculver 13y ago

Inputting "こんにちは。元気ですか？" caused an application error: [ArgumentException: Error serializing value 'ᄳᅳᅋᅁᅏტ㈣䳷ᅇᄹᄫ�' of type 'System.String.'] After realizing it was "？" that was breaking everything, I ended up with this round trip: "こんにちは。元気ですか。" → "ᄳᅳᅋᅁᅏტ㈣䳷ᅇᄹᄫტ" → "こんにちは。ጃ⷗ですか。" It's broken. I suspect Unicode requires more careful manipulation than OP anticipated. :-)

deleted 13y ago

[deleted]

njharman 13y ago

I just realized that 13 was probably chosen for rot13 cause that's half the number of letters in English alphabet. I miss "obvious" stuff like that all the time.

rottytooth 13y ago

I put in a fix for CJK and the result is: nearly everything that's not CJK now rotates into it and back out; CJK is an huge section of the Basic Multilingual Plane. The fix invalidates rotations done with rot8000 before the fix, unfortunately.