OpenEuphoria

Re: stable sorting

• Posted by Juergen Luethje <eu.lue at gmx.de> Feb 26, 2003
• 464 views

Hi Kat, you wrote:

> On 25 Feb 2003, at 17:02, Juergen Luethje wrote:

[...]

>> Say I have a list of records with student names and marks, already
>> sorted by name. Then i want to sort this list by mark, so that students
>> with the same mark remain listed in alphabetical order.
>
> <snip>
>
>> Is there a library in the archive, with which this can be achieved?
>> I didn't find one.
>
> Yes, sorttok(). Several examples of sorting multiple fields at the same time
> are in the readme.html : See:
> http://www.pell.net/warning/ai/strtok-v2-1.html#sorttok

Great, thank you!

> It handles such things as a descending sort in one field, then an ascending
> sort within that sort, and a descending in that sort, etc,, as many internal
> sorts as you have fields in the list, mixing up-down sorts as you want.
>
> If you want your list not sorted, but you want the trace route thru the list
> in
> the sort order you specify, see sortntok().

The functions are very useful and flexible! I downloaded 'strtok-v2-1.zip'
and am very curious to have a closer look at the source code, if I've
some more time. Hopefully I'll understand, how it works.


> Strtok v2.2 is due out someday in March 2003.

Well.. how about making sorttok() and sortntok() (or two additional
functions) even more generic? At the moment, one "record" must be a
string:

sorted = sorttok({"Fred,Astaire,45,Alberta,Canada",
                  "Lucy,Ball,56,Barre,North Dakota",
                  "Red,Skelton,34,London,England",
                  "Pierre,du Pont,12,Paris,France"},
                  3, ',')

I don't always have comma (or semicolon or whatever) delimeted fields.
So wouldn't it be more generic, if one field is an atom or a sequence?
E.g.:

sorted = sorttok({{"Fred","Astaire",45,"Alberta","Canada"},
                  {"Lucy","Ball",56,"Barre","North Dakota"},
                  {"Red","Skelton",34,"London","England"},
                  {"Pierre","du Pont",12,"Paris","France"}},
                  3, ',')

> Kat

Best regards,
   Juergen

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