OpenEuphoria

Re: Sorting by sequence member`

• Posted by Tony Steward <tony.steward at gmail.com> Oct 10, 2004
• 421 views

Great that works for me THANKS


On Sun, 10 Oct 2004 12:39:17 +0200, Juergen Luethje <j.lue at gmx.de> wrote:
> 
> 
> Tony Steward wrote:
> 
> > I have looked at custom sort and the demo csort.exe but it just
> > doesn't sink in how to do it.
> >
> > Can't run csort.ex as xp complains about running dos program
> >
> > Tony
> >
> >
> > On Sun, 10 Oct 2004 02:10:07 -0700, irv mullins <guest at rapideuphoria.com>
> > wrote:
> >>
> >> posted by: irv mullins <irvm at ellijay.com>
> >>
> >> Tony Steward wrote:
> >>>
> >>> Kat your sorttok doesn't seem to like my data layout (i think) as it
> >>> returns nothing.
> >>
> >>
> >> Tony: I think custom_sort() will do what you want. Look it up in the
> >> docs (it's 5 a.m. here, I've been up since 2 a.m. and am too groggy to
> >> write a demo :)
> 
> The following code is slightly modified after the code that Andy Serpa
> posted here on 25 Feb 2003. Very clean, straightforward, and flexible.
> Thanks again, Andy!
> 
> }}}
<eucode>
> object sort_i
> 
> function compare_index (object x1, object x2)
>   -- Don't call this function directly, see below.
>   integer comp, ix
> 
>   if integer(sort_i) then
>      if sort_i > 0 then
>         return  compare(x1[sort_i], x2[sort_i])
>      else
>         return -compare(x1[-sort_i], x2[-sort_i])
>      end if
>   end if
> 
>   for j = 1 to length(sort_i) do
>      ix = sort_i[j]
>      if ix > 0 then
>         comp =  compare(x1[ix], x2[ix])
>      else
>         comp = -compare(x1[-ix], x2[-ix])
>      end if
>      if comp != 0 or j = length(sort_i) then
>         return comp
>      end if
>   end for
> end function
> 
> global function flex_sort (sequence s, object i)
>   -- This is the function you actually call.
>   -- s = sequence to be sorted (assumed to be at least 2-dimensional)
>   -- i = integer index of element (column) to sort on,
>   -- or sequence of indexes to sort on multiple fields
>   -- (in order of preference).
>   -- If any given index is positive, then it will sort that element in
>   ascending order.
>   -- If negative, it will sort that element in descending order.
>   sort_i = i
>   return custom_sort(routine_id("compare_index"), s)
> end function
> </eucode>
{{{

> 
> Regards,
>   Juergen
> 
> --
> .... there are two ways of constructing a software design: One way is to
> make it so simple that there are /obviously/ no deficiencies and the other
> is to make it so complicated that there are no /obvious/ deficiencies.
> [C.A.R. Hoare (1987), The Emperor's Old Clothes]
> 
> 
> 
> 
> 


-- 
Regards
Tony Steward
www.locksdownunder.com

IF IT IS TO BE IT IS UP TO ME!