{GenSort - Sample sort procedure generator.		      }
  {				   Frank Rubin	Nov. 14, 2004 }
  {   One sort procedure is needed for each different array or}
  {each type of array to be sorted.			      }
  {							      }
  {sortname  the name for the generated sort procedure.       }
  {	     Example:  TimeSort 			      }
  {arname    (optional) the name of the array to be sorted.   }
  {	     If arname is given, then a procedure to sort that}
  {	     specific array will be generated.	If arname is  }
  {	     omitted then the generated sort procedure will   }
  {	     get the array name as a parameter. 	      }
  {	     Example:  Inventory			      }
  {artype    the type of the array to be sorted.	      }
  {	     Example:  array of trans_rec		      }
  {eltype    the type of each array element.		      }
  {	     Example:  customername			      }
  {field1,field2,field3 				      }
  {	     (optional) sort fields within each record, in    }
  {	     order of importance.			      }
  {	     Example:  last_name, first_name,)		      }
  {							      }
  {   Sample calls to GenSort, with a sample call to each of  }
  {the generated sort procedures:			      }
  {							      }
  {%GenSort (VolSort,, array of vol, real,,,);		      }
  {VolSort (packvolume, 0, maxpacks);			      }
  {							      }
  {%GenSort (TranSort, trantable, tranlist, tranitem,	      }
  {	     date, time,);				      }
  {TranSort (1, trancount);				      }

%Procedure  GenSort (sortname: code;	{Name for the resulting sort procedure}
		     arname: code;	{Optional array name}
		     artype: code;	{Type of the array to be sorted}
		     eltype: code;	{Type of each array element}
		     field1,field2,	{Optional sort fields}
			field3: code);
%Var
  fieldcount: integer;			{Num of optional fields specified}
  sarray: code;

%Begin	{GenSort}
%fieldcount := 0;			{How many sort fields were given?}
%if  field1
     then  %fieldcount := 1;
%if  field2
     then  %fieldcount := 2;
%if  field3
     then  %fieldcount := 3;

   {External sort procedure}
%if  arname
then  %begin
%sarray :=arname;
Procedure  SortName (const lo_end,hi_end: longint);
%end;
else  %begin
%sarray :=sortar;
Procedure  SortName (var sortar: artype;
		     const lo_end,hi_end: longint);
%end;

   {Internal recursive sort procedure}
Procedure  Sort (const bot,top: longint);
Var
  i,j: longint; 			{Loop indexes}
  pivot: eltype;			{Pivot element}
  temp: eltype; 			{Temp for swapping}
Begin  {Sort}
  i := bot;				{Start at the ends of the range}
  j := top;
  pivot := sarray[(bot+top) shr 1];	{Choose the middle element}
  repeat%;
%if  fieldcount = 0  then
    while  sarray[i] < pivot  do	{Skip low elements at the bottom}
%;
%if  fieldcount = 1  then
    while  sarray[i].field1 < pivot.field1  do	      {Skip low elements at the bottom}
%;
%if  fieldcount = 2  then  %begin
      {Skip low elements at the bottom}
    while   (sarray[i].field1 < pivot.field1) or
	   ((sarray[i].field1 = pivot.field1) and
	    (sarray[i].field2 < pivot.field2))	do
%; %end;
%if  fieldcount = 3  then  %begin
      {Skip low elements at the bottom}
    while   (sarray[i].field1 < pivot.field1) or
	   ((sarray[i].field1 = pivot.field1) and
	    (sarray[i].field2 < pivot.field2)) or
	   ((sarray[i].field1 = pivot.field1) and
	    (sarray[i].field2 = pivot.field2) and
	    (sarray[i].field3 < pivot.field3))	do
%; %end;
      i := i + 1;
%if  fieldcount = 0  then
    while  sarray[j] > pivot  do	{Skip high elements at the top}
%;
%if  fieldcount = 1  then
    while  sarray[j].field1 > pivot.field1  do	      {Skip high elements at the top}
%;
%if  fieldcount = 2  then  %begin
      {Skip high elements at the top}
    while   (sarray[j].field1 > pivot.field1) or
	   ((sarray[j].field1 = pivot.field1) and
	    (sarray[j].field2 > pivot.field2))	do
%; %end;
%if  fieldcount = 3  then  %begin
      {Skip high elements at the top}
    while   (sarray[j].field1 > pivot.field1) or
	   ((sarray[j].field1 = pivot.field1) and
	    (sarray[j].field2 > pivot.field2)) or
	   ((sarray[j].field1 = pivot.field1) and
	    (sarray[j].field2 = pivot.field2) and
	    (sarray[j].field3 > pivot.field3))	do
%; %end;
      j := j - 1;
    if	i <= j				{Swap these out-of-order elements}
	then  begin
		temp := sarray[i];
		sarray[i] := sarray[j];
		sarray[j] := temp;
		i := i + 1;
		j := j - 1;
	      end;
  until  i > j;
  if  bot < j
      then  Sort (bot, j);
  if  i < top
      then  Sort (i, top);
End;  {Sort}

Begin
  Sort (lo_end, hi_end);
End;
%End;  {GenSort}