# 'aábcðdeéfghiíjklmnoópqrstuúvwxyýzþæö'
46
# 'AÁBCÐDEÉFGHIÍJKLMNOÓPQRSTUÚVWXYÝZÞÆÖ'
46
lc=.'aábcðdeéfghiíjklmnoópqrstuúvwxyýzþæö'
uc=.'AÁBCÐDEÉFGHIÍJKLMNOÓPQRSTUÚVWXYÝZÞÆÖ'
13 rottN ((#L:0~ lc;uc) u:i.2^16) 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
|domain error
| 13 rottN(( #L:0~lc;uc)u:i.2^16)'prófaþetta með íslenzkum
stöfunum æÆöðÐþÞ'
2011/12/23 Raul Miller <rauldmil...@gmail.com>
> True.
>
> The underlying problem is that the algorithm itself is language specific.
>
> I do not know how to implement a consistent version of this mechanism
> for German, for example. The problem with German is that ß does not
> have an "upper case" variant. So rotation of lower case letters in
> german would have to be different from rotation for upper case letter.
> Perhaps that's acceptable?
>
> If it makes sense to apply the same rotation to cycles of differing
> lengths, here's a version which works for the arbitrary cases
> involving unicode characters which J can handle.
>
> NB. n: boxed character sequences to be rotated (must not overlap)
> NB. m: how much to rotate them
>
> rottN=: 2 :0
> D=. m (|. ; 3 u: ])&.> boxopen n
> {&(; (0{::[)`(1{::[)`]}&.>/ D,<u:i.2^16)@(3&u:)
> )
>
> 5 rottN '0123456789' '123'
> 678
>
> ;/a.{~65 97+/i.26
> +--------------------------+--------------------------+
> |ABCDEFGHIJKLMNOPQRSTUVWXYZ|abcdefghijklmnopqrstuvwxyz|
> +--------------------------+--------------------------+
> 13 rottN (;/a.{~65 97+/i.26) 'testing'
> grfgvat
> 13 rottN (;/a.{~65 97+/i.26)^:2 'testing'
> testing
>
> Or, using character selectors instead of character sequences (and
> living with unicode character ordering):
>
> 13 rottN ((#L:0~ lc;uc) u:i.2^16) 'prófaþetta með íslenzkum stöfunum
> æÆöðÐþÞ'
>
> But it's up to you to define lc and uc
>
> FYI,
>
> --
> Raul
>
>
> 2011/12/23 Björn Helgason <gos...@gmail.com>:
> > This is only english
> >
> > _1 rottn 1 rottn 'testing'
> > testing
> >
> > Does not work with my alpha
> >
> > _1 rottn 1 rottn 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
> > prófaþetta með Ãslenzkum stöfunum æÆöðà þÞ
> > 3 u: 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
> > 112 114 195 179 102 97 195 190 101 116 116 97 32 109 101 195 176 32
> > 195 173 115 108 101 110 122 107 117 109 32 115 116 195 182 102 117 110
> > 117 109 32 195 166 195 134 195 182 195 176 195 144 195 190 195 158
> >
> > 3 u: 7 u: 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
> > 112 114 243 102 97 254 101 116 116 97 32 109 101 240 32 237 115 108
> > 101 110 122 107 117 109 32 115 116 246 102 117 110 117 109 32 230 198
> > 246 240 208 254 222
> > # 3 u: 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
> > 53
> > # 3 u: 7 u: 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
> > 41
> > 8 u: 4 u: 3 u: 7 u: 'prófaþetta með íslenzkum stöfunum æÆöðÐþÞ'
> > prófaþetta með íslenzkum stöfunum æÆöðÐþÞ
> >
> > # 3 u: 7 u: 'aábcðdeéfghiíjklmnoópqrstuúvwxyýzþæö'
> > 36
> > # 3 u: 7 u: 'AÁBCÐDEÉFGHIÍJKLMNOÓPQRSTUÚVWXYÝZÞÆÖ'
> > 36
> >
> >
> >
> > 2011/12/23 Raul Miller <rauldmil...@gmail.com>
> >
> >> Here's another variation:
> >>
> >> rotn=: 1 :'{&((65 97 +/~ i.26) m&|.@[`[`]} i.256)&.(a.&i.)'
> >>
> >> 1 rotn 'testing'
> >> uftujoh
> >> 13 rotn 'testing'
> >> grfgvat
> >> 13 rotn 13 rotn 'testing'
> >> testing
> >> _1 rotn 1 rotn 'testing'
> >> testing
> >>
> >> In this expression, each arbitrary constant is used only once:
> >>
> >> 26: letters in the alphabet
> >> 65: 'A'
> >> 97: 'a'
> >> 256: the number of character codes
> >>
> >> I could replace 256 with #a. but I do not think that adds any clarity.
> >>
> >> That said...
> >> rottn=: 1 :'{&((65 97 +/~ i.26) m&|.@u:@[`[`]} a.)&(3&u:)'
> >>
> >> --
> >> Raul
> >> On Fri, Dec 23, 2011 at 11:27 AM, Raul Miller <rauldmil...@gmail.com>
> >> wrote:
> >> > Wait, bad idea... that rot13 only works because 13 is a factor of 26.
> >> >
> >> > Instead (and this is a fast bug fix, I have not thought much about
> >> > more elegant forms, though several paths for rephrasing come to mind):
> >> >
> >> > rotN=: 1 :'{&((65 97 +/ m |. i.26) ((65 97 +/i.26)}) i.256)&.(a.&i.)'
> >> >
> >> > --
> >> > Raul
> >> >
> >> > On Fri, Dec 23, 2011 at 11:21 AM, Raul Miller <rauldmil...@gmail.com>
> >> wrote:
> >> >> Here's what I use for rot13:
> >> >>
> >> >> rot13=: {&((65 97+/~i.2 13) |.@[} i.256)&.(a.&i.)
> >> >>
> >> >> If I wanted to generalize that, I would probably go with:
> >> >>
> >> >> rotN=: 1 :'rot13=: {&((65 97+/~i.2,m) |.@[} i.256)&.(a.&i.)'
> >> >>
> >> >> 13 rotN 'testing'
> >> >> grfgvat
> >> >> 13 rotN rot13 'testing'
> >> >> testing
> >> >>
> >> >> --
> >> >> Raul
> >> >>
> >> >> On Fri, Dec 23, 2011 at 11:00 AM, Lorenzo Costanzia di Costigliole
> >> >> <lorenzo.costan...@gmail.com> wrote:
> >> >>> NB. What is the most elegant way to rotate uppercase
> >> >>> NB. and lowercase letters by n? ("rotation cipher")
> >> >>>
> >> >>> c2n=: a.&i.
> >> >>>
> >> >>> lc=: >&96 *. <&123
> >> >>> uc=: >&64 *. <& 91
> >> >>>
> >> >>> s=: 'Btggn Rwgxhibph 2011 id iwt Y-Egdvgpbbxcv bpxaxcv axhi!'
> >> >>>
> >> >>>
> >> >>>
> >> >>> NB. I came up with those, but I think there’s still room for
> >> improvement
> >> >>> NB. (Isn't there something in the J-Phrases?)
> >> >>>
> >> >>> NB. uppercase -> 2, lowercase -> 1, else -> 0
> >> >>> cl=: +:@uc + lc
> >> >>> cl`(] , ([: 26&| +&n)&.(-&97) ,: ([: 26&| +&n)&.(-&65))}&.c2n s
> >> >>>
> >> >>> ((] + ] ]`([: 26&| n + ])@.((0~:[)"0) [ - ]) (97&*@lc +
> 65&*@uc))&.c2n
> >> s
> >> >>>
> >> >>> NB. Enumerate all possibilities
> >> >>> |: ((] + ] (26 # ])`([: 26&| (i.26) + ])@.((0 ~: [)"0) [ - ])
> (97&*@lc
> >> >>> + 65&*@uc))&.c2n s
> >> >>>
> >> >>> NB. Thanks!
> >> >>>
> ----------------------------------------------------------------------
> >> >>> For information about J forums see
> http://www.jsoftware.com/forums.htm
> >> ----------------------------------------------------------------------
> >> For information about J forums see http://www.jsoftware.com/forums.htm
> >>
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
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