Delphi

Bit-packed structure (record) in Free Pascal and Delphi

Submitted by Serguei_Tarassov on

Here is the code explaining some methods to pack bit accessing logic in your program.

program project1;
 
type
  TRec1 = packed record // Doesn't pack at all
    b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15, b16: boolean;
  end;
 
  TRec2 = bitpacked record // Free Pascal specific
    b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15, b16: boolean;
  end;
 
  TRecByte = (b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15, b16);
  TRecBytes = set of TRecByte;
var
  r1: TRec1;
  r2: TRec2;
  s1: TRecBytes;

Why need to specify unit names?

Submitted by Serguei_Tarassov on

In the previous article "Crack C# namespaces in 30 seconds" I demonstrated how to make error having no idea about it. So you will have a lovely time in debugging. But in C# you're condemned to use using directive or your code will be unreadable with all these horrible specifiers MySolution.AppModules.Accounting.AccountingType.DefaultValue.

Delphi and Free Pascal bencmark: array vs TList vs dynamic array

Submitted by Serguei_Tarassov on

Let's perform a simple benchmark testing the random and sequential access to arrays and lists. I would like to compare:

  • static array with predefined size (allocated on stack)
  • TList container class (allocated on heap)
  • dynamic array (allocated on heap)
  • generic Delphi TList or Free Pascal TFPGList (allocated on heap)

I use an array/list of 10M elements of integer and varaint data type. You can change the type definition in "type" section if need to test other cases.

Crack C# namespaces in 30 seconds

Submitted by Serguei_Tarassov on

The namespaces conception in C# seems exhaustive and insufficient at the same time in comparison with strong module notation like in Oberon-2 and even with modular programming like in Free Pascal/Delphi.

Why insufficient? You cannot declare constants and functions within namespaces but you should add a class with constant field or static method for it. It's really sad...

Why exhaustive? The "using" directive with such introduced classes is the source of unexpected errors. Here is an example below.

Make error "Fatal: Command arguments too long"

Submitted by Serguei_Tarassov on

This bug is reproduced on Delphi 7 and C++Builder 6 at least (probably in later versions too) when starting Borland make utility. Indeed, the message "Fatal: Command arguments too long" and the real problem are as like as chalk and cheese.

Check the length of your PATH variable. In my case the length was > 400 characters. Deleting some paths reduced the length down to 300-350 characters and solve the problem.

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