[fpc-devel] Encoded AnsiString

[Michael Van Canneyt]

On Sun, 29 Dec 2013, Hans-Peter Diettrich wrote:

> Inspired by the current Lazarus discussion I'd like to learn more about the 
> current state of the implementation of the new AnsiStrings.
>
> In case nothing has be done yet, I'd suggest to extend TAnsiRec by the new 
> codePage and elemSize fields (words). These can be zero for now, so that the 
> remaining codebase is not affected. Then it will be possible to play around 
> with encoded strings, using the codePage field.
>

All this is done already a long time ago in trunk.
We're way past that stage.

Current stage is the creation of a unicode RTL, where all base file/string 
operations accept unicode strings. This is done too.

Next step is creation of the unicode RTL, where "string" = "widestring".
This will be combined with the dotted unit filenames, to be Delphi 2010+ compatible.

To allow people to choose, 2 RTLs will be created: one unicode (string=ansistring), 
one non-unicode (string=widestring).

This will result (probably) in 2 paths:
units/os-cpu
units/os-cpu-unicode
This is not decided yet.

I planned the work in februari/march.

> A related question:
> Why is the string length set to zero in NewAnsiString, when the allocated 
> Length is already known?

Because the allocated memory length is not necessarily equal to the string length.
If you have a string of length 50, setting the length to 25 will not discard 
and reallocate the memory block, but merely set the character length to 25.

Michael.