Re: Sorting implemented in Guile standard library

[Bill Markmann <bmarkmann@gmail.com>]

I'm not a guile hacker, but looking at the source for "libguile/sort.c", it
looks like quicksort:

#include "sort.h"

/* We have two quicksort variants: one for SCM (#t) arrays and one for
   typed arrays.
*/

#define NAME        quicksort
#define INC_PARAM   ssize_t inc,
#define VEC_PARAM   SCM * ra,
#define GET(i)      ra[(i)*inc]
#define SET(i, val) ra[(i)*inc] = val
#include "quicksort.i.c"

The sort functions look like they call "s_scm_restricted_vector_sort_x",
and then in there:

  if (handle.element_type == SCM_ARRAY_ELEMENT_TYPE_SCM)
    quicksort (scm_array_handle_writable_elements (&handle) - dims[0].lbnd
* dims[0].inc,
               spos, epos, dims[0].inc, less);
  else
    quicksorta (&handle, spos, epos, less);


I'd assume that's what is underneath (sort items less) and friends.  Just a
guess, though... :-)


On Sun, Aug 16, 2020 at 4:56 PM Zelphir Kaltstahl <
zelphirkaltstahl@posteo.de> wrote:

> Hello Guile Users!
>
> I was checking out
> https://www.gnu.org/software/guile/manual/html_node/Sorting.html and
> noticed, that the definition of `sort` does not mention, which algorithm
> is used for sorting:
>
> > Sort the sequence items, which may be a list or a vector. less is used
> for comparing the sequence elements. This is not a stable sort.
>
> So my question is: Which algorithm is used for Guile's `sort` function?
>
> Regards,
> Zelphir
>
> --
> repositories: https://notabug.org/ZelphirKaltstahl
>
>
>