Peter Popov wrote:
Hi All
As you now, the Slice function (internal to the Delphi compiler) is
not currently implented in fpc (see bug
http://www.freepascal.org/bugs/showrec.php3?ID=2856). I am wondering
how easy it is to implement/circumvent this problem. In these regard,
can someone shed light on the following two things:
1. Are open array parameters in fpc functions and procedure
implemented in the same way as in Delphi. That is,
procedure MyFunc(x: array of integer)
is actually compiled as
procedure MyFunc(count: Integer; x: ^Integer)
and inside MyFunc, x is treated as a zero based arrays of size count,
and count is only accessible through High(x).
Are fpc open arrays done in the same way?
2. What is the internal structure of a dynamic array/open array in
fpc. Maybe, given a pointer and a array size, one can hack a
temprorary dynamic array structure (probably without typecasting) and
pass it as an open array parameter. Even without typecasting, this
will let me compile existing delphi code.
Thanks
Peter
Array slicing is already possible with the use of absolute eg:
program Project1;
{$mode objfpc}{$H+}
procedure Crap(var A: array of Integer);
var
b: array[1..3] of Integer absolute A[2];
i: Integer;
begin
for i:=1 to 3 do b[i]:=0;
end;
var
a: array of Integer;
i: Integer;
begin
SetLength(a, 6);
for i:=0 to 5 do
a[i]:=i + 1; // 1 to 6
Crap(a);
for i:=0 to 5 do
Write(a[i], ' ');
Writeln;
end.
Output is 1 2 0 0 0 6
Ales
_______________________________________________
fpc-devel maillist - [email protected]
http://lists.freepascal.org/mailman/listinfo/fpc-devel
