[Lazarus] Can't compile trunk with fpc 2.4.5 under ubuntu

[Sven Barth]

Am 28.02.2012 15:31, schrieb Martin Schreiber:
> Am 28.02.2012 16:13, schrieb Sven Barth:
>> Am 28.02.2012 15:40, schrieb Hans-Peter Diettrich:
>>> Sven Barth schrieb:
>>>
>>>> Before Delphi 2009 you might have been right, but with that version
>>>> Embarcadero did a cut and we now need to adapt and live with that.
>>>
>>> I dare to disagree. A "ByteString" only requires a dedicated encoding
>>> (value), which makes it incompatible with other encodings, and thus
>>> disables all conversions. Such an encoding doesn't break Delphi
>>> compatibility, but allows to use all stringhandling functions with it.
>>
>> And instead of introducing yet another type or another special encoding
>> we could just leverage the features FPC has today and use TBytes.
>>
> Or even better, use FPC 2.6 AnsiString and UnicodeString and drop the
> encoding aware FPC 2.7 AnsiString. ;-)
>
> BTW, please have a look into the different string concatenation
> compilerproc, it is probably not so easy to model that with equal or
> better performance with TBytes and operator overloading. Is it possible
> with operator overloading to combine different types?

Did you look at the 2.7.1 or 2.6.0 implementation of these procs? If the 
2.6.0 one then I suggest you to look at the 2.7.1 ones and reconsider 
your statement ;)

Nevertheless I'll try to do a speed measurement with TBytes and 
AnsiString both in 2.6 and 2.7.1. If we can improve the performance of 
FillChar (which would also benefit class creation btw) then this might 
be a rather performant alternative ;)

> "
> <TBytes>:= <TBytes> + 'stringconstant' + <TBytes> + <AnsiString>;
> "

I quickly adjusted my test program:

=== source begin ===

program bytearraytest;

{$mode objfpc}

type
   TBytes = array of Byte;

operator + (aLeft, aRight: TBytes): TBytes;
begin
   SetLength(Result, Length(aLeft) + Length(aRight));
   if Length(aLeft) > 0 then
     Move(aLeft[0], Result[0], Length(aLeft) * SizeOf(Byte));
   if Length(aRight) > 0 then
     Move(aRight[0], Result[Length(aLeft)], Length(aRight) * SizeOf(Byte));
end;

operator + (aLeft: TBytes; aRight: AnsiString): TBytes;
begin
   SetLength(Result, Length(aLeft) + Length(aRight));
   if Length(aLeft) > 0 then
     Move(aLeft[0], Result[0], Length(aLeft) * SizeOf(Byte));
   if Length(aRight) > 0 then
     Move(aRight[1], Result[Length(aLeft)], Length(aRight) * SizeOf(Char));
end;

operator + (aLeft: AnsiString; aRight: TBytes): TBytes;
begin
   SetLength(Result, Length(aLeft) + Length(aRight));
   if Length(aLeft) > 0 then
     Move(aLeft[1], Result[0], Length(aLeft) * SizeOf(Char));
   if Length(aRight) > 0 then
     Move(aRight[0], Result[Length(aLeft)], Length(aRight) * SizeOf(Byte));
end;

var
   arr1, arr2, arr3: TBytes;
   b: Byte;
   i: LongInt;
   s: AnsiString;
begin
   SetLength(arr1, 5);
   for i := 0 to 4 do
     arr1[i] := i + 1;
   SetLength(arr2, 5);
   for i := 0 to 4 do
     arr2[i] := i + 6;
   arr3 := arr1 + arr2;
   for b in arr3 do
     Write(b, ' ');
   Writeln;
   arr3 := Copy(arr2, 2, 2);
   for b in arr3 do
     Write(b, ' ');
   Writeln;
   s := 'Hello World';
   arr3 := arr1 + 'stringconstant' + arr2 + s;
   for b in arr3 do
     Write(b, ' ');
   Writeln;
end.

=== source end ===

And here is what it prints:

=== source begin ===

PS P:\tests\oneshots> .\bytearraytest.exe
1 2 3 4 5 6 7 8 9 10
8 9
1 2 3 4 5 115 116 114 105 110 103 99 111 110 115 116 97 110 116 6 7 8 9 
10 72 101 108 108 111 32 87 111 114 108 100

=== source end ===

Regards,
Sven