demo for using of qsort from lib and a little problem with it - Gpc

6 Sep 1997


      program Sort_Test;
{ demo for using of the qsort function from gpc }
{ sven@rufus.central.de }
uses
  grx20;
type
  TestType = Integer; { works with Real, ShortInt, Integer, LongInt }
                      { crashs with Byte }
  StrType  = String(8);
  FuncType = ^Function: TestType;
function CompNum(var e1, e2: TestType):Integer;
Var
  r : Real;
begin
  r       := e1 - e2;
  CompNum := Round(r);
end;
function CompString(var e1, e2: StrType):Integer;
begin
  if e1 = e2 then
    CompString := 0
  else if e1 > e2 then
    CompString := 1
  else
    CompString := -1;
end;
procedure qsort(var base; numelem, size : Integer; cmp: FuncType); C;
var
  i  : Integer;
  ta : Array[1..5] of TestType;
  tb : Array[1..5] of StrType;
begin
  ta[1] := 4;
  ta[2] := 2;
  ta[3] := 1;
  ta[4] := 3;
for i := 1 to 5 do Writeln(ta[i]);
qsort(ta, 5, Sizeof(ta[1]), @CompNum);
  Writeln;
for i := 1 to 5 do Writeln(ta[i]);
  Writeln;
tb[1] := 'Peter';
  tb[2] := 'Paul';
  tb[3] := 'Mary';
  tb[4] := 'Sven';
  tb[5] := 'Adam';
qsort(tb, 5, Sizeof(tb[1]), @CompString);
for i := 1 to 5 do Writeln(tb[i]);
  Writeln;
end.