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/*-------------------------------------------------------------------------
*
* lispsort.c
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/lib/Attic/lispsort.c,v 1.19 2003/08/04 02:39:59 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#ifdef NOT_USED
/*
** lisp_qsort: Takes a lisp list as input, copies it into an array of lisp
** nodes which it sorts via qsort() with the comparison function
** as passed into lisp_qsort(), and returns a new list with
** the nodes sorted. The old list is *not* freed or modified (?)
*/
List *
lisp_qsort(List *the_list, /* the list to be sorted */
int (*compare) ()) /* function to compare two nodes */
{
int i;
size_t num;
List **nodearray;
List *tmp,
*output;
/* find size of list */
num = length(the_list);
if (num < 2)
return copyObject(the_list);
/* copy elements of the list into an array */
nodearray = (List **) palloc(num * sizeof(List *));
for (tmp = the_list, i = 0; tmp != NIL; tmp = lnext(tmp), i++)
nodearray[i] = copyObject(lfirst(tmp));
/* sort the array */
pg_qsort(nodearray, num, sizeof(List *), compare);
/* lcons together the array elements */
output = NIL;
for (i = num - 1; i >= 0; i--)
output = lcons(nodearray[i], output);
return output;
}
#endif
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