program Primtester_2;

// simple primtester between range for perfomance- and filehandling 
// has a function and procedure, no globals, locs = 62
// to teach the function with or without brake shows perfomance!


var
mylist: TStringlist;
beforetime, aftertime: string;
//timedelta: integer;

function checkPrim(acti: integer): boolean;
var
  j: Integer;
  isprim: boolean;
begin
  isprim:= true;
  for j:= 2 to round(sqrt(acti)) do 
   if ((acti mod j) = 0) then begin
     isprim:= false
     break
  end;   
  result:= isprim;
end;


procedure testPrimNumbers(from_range, to_range: integer);
var acti, count: integer;
begin
   count:= 0;
   mylist:= TStringlist.create;
  for acti:= from_range to to_range do begin
    inc(acti)
    //writeln('debug count'+inttostr(acti))
    if checkprim(acti) then begin
      inc(count)
      mylist.add(inttostr(count) +':'+inttoStr(acti))
      //writeln(inttostr(count) +':'+ inttostr(acti))
     end 
  end
   //insert new lines to an existing file-list
   {mylist.LoadFromFile('primetest3.txt');}
   //add a string to the end of list
   {sl.Add('hell\*/bell');} 
end;

//main script
begin
  //irange:= strtoint(readln('how great is the range ?'));
  //check time performance
  beforetime:= now;
    testPrimNumbers(20, 10000);
  aftertime:= now;
  writeln('start: '+ beforetime)
  writeln('stop: ' + aftertime)
  mylist.add(memo2.text)
  mylist.savetoFile('primetest7.txt')
  memo2.lines.loadfromFile('primetest7.txt')     
  mylist.free;
  //orthogonal and idempotent
end.