Hi,
I was thinking of fixing the character comparison by replacing them with
their numeric equivalent but I discovered what Devon just mentioned :
a. i. 'éabc'
195 169 97 98 99
0{'éabc'
�
1{'éabc'
�
0 1{'éabc'
é
$'é'
2
I'm currently reading
https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/
to see how I will deal with this.
Jimmy
On Sat, Dec 10, 2022 at 2:49 PM Devon McCormick <[email protected]> wrote:
> Raul's expression "<&(3&u:)" made me think of the endless complications for
> character comparison once you include multi-byte representations as in
> Unicode.
> So this initial expression works fine but extending it beyond elements of
> a.
> leads to ambiguity.
> 'A' <&(3&u:) 'a'
> 1
> a. i. 'Aa' NB. confirming the inequality
> 65 97
> NB. (load "define-abbrev-table.el") NB. This allows me to enter special
> characters in emacs
> 'α' <&(3&u:) 'a'
> 0 0
> 'α' <&(3&u:) 'β' NB. So should we say alpha is only partially
> less than beta?
> 0 1
> (<a.) i. &> 'α';'β'
> 206 177
> 206 178
>
>
>
> On Sat, Dec 10, 2022 at 7:28 AM 'Mike Day' via Chat <[email protected]>
> wrote:
>
> > Yes, my suggestion was an example of using /:~ to exploit J's inbuilt
> > ordering for a
> > simple, quick answer; but maybe
> > /:~ 'aA1.;'
> > (eg) isn't the order relation you require, so I agree with Raul.
> >
> > Mike
> >
> > Sent from my iPad
> >
> > > On 9 Dec 2022, at 19:22, Jimmy Gauvin <[email protected]> wrote:
> > >
> > > Hi,
> > >
> > > the domain of < and others could be extended to include characters.
> > >
> > > Sorting with /: and \: implies there is an "order" relation between
> > > characters.
> > >
> > >
> > > J
> > >
> > >> On Fri, Dec 9, 2022 at 6:21 AM Donna Ydreos <[email protected]>
> wrote:
> > >>
> > >> The domain of < is numeric. You can create a function for letters with
> > >> reference to alphabetic order or some given order including say all
> ASCI
> > >> characters.
> > >>
> > >>>> On Dec 9, 2022, at 3:47 AM, Jimmy Gauvin <[email protected]>
> > wrote:
> > >>>
> > >>> Hi all,
> > >>>
> > >>> testing character data for equality works fine but testing for
> relative
> > >>> order does not.
> > >>>
> > >>> 'a'<'v'
> > >>>
> > >>> |domain error
> > >>>
> > >>> | 'a' <'v'
> > >>>
> > >>> 'a'='v'
> > >>>
> > >>> 0
> > >>>
> > >>> Is this explained somewhere ?
> > >>>
> > >>> Thanks,
> > >>>
> > >>> Jimmy
> > >>>
> ----------------------------------------------------------------------
> > >>> For information about J forums see
> http://www.jsoftware.com/forums.htm
> > >>
> > >> ----------------------------------------------------------------------
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> > >>
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> >
>
>
> --
>
> Devon McCormick, CFA
>
> Quantitative Consultant
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
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