AquilaX's development blog » Pascal

DateSerial

AquilaX — Thu, 06 Mar 2008 08:14:03 +0000

Working with MS Access's date/time type is a total headache. Which goes first the month or the day, or it depends on the values of the month and the day, or maybe on the Regional settings? There's a medicine for this illness and it's called DateSerial. Fortunately it works for INSERT as well as SELECT statements so i use this simple function in Delphi deal with date/time.

 
function DateToSQL(FDate:TDate):String;
begin
  Result := 'DateSerial('+FormatDateTime('yyyy,mm,dd', FDate)+')';
end;

Greatest Common Divisor in Pascal

AquilaX — Wed, 12 Dec 2007 10:24:14 +0000

A short iterational algorithm for calculating the greatest common divisor using the Euclidean algorithm.

 
function gcd(a, b:Longword):Longword;
var
  t:Longword;
begin
  while b <> 0 do
  begin
    t := b;
    b := a mod b;
    a := t;
  end;
  gcd := a;
end;

This function can be used for calculating Euler's Totient function:

 
function fi(a:Longword):Longword;
var
  i:Longword;
  count:Longword;
begin
  if a = 1 then
  begin
    count := 1;
    Exit
  end;
  count := 0;
  for i := 1 to a do
  begin
    if gcd(i, a) = 1 then
      count := count +1;
  end;
  fi := count;
end;

N.B. Keep in mind that this algorithms are far from optimal.

Datecs FP-550T

AquilaX — Sat, 03 Nov 2007 23:05:07 +0000

If you're planning to develop for FP-550T Fiscal printer through the COM Server, don't download it from the website. Get it from Datecs' FTP Server: ftp.datecs.bg. The version on the website is obsolete and doesn't work correctly.
This may save you a support call.