[Lazarus] Strings

[Marco van de Voort]

On Wed, Nov 18, 2009 at 07:12:24AM +0100, J?rgen Hestermann wrote:
> > And I think shortstring should generally be discouraged. The standard is
> > always "255 is enough", but sooner or later somebody hits it:
> 
> That's like saying that short integer types like byte or word should be
> discouraged and only Int64 should be used.

Well, can be speed penalties on byte and word indeed.
 
> Shortstrings are just a completely different string type than ansistrings.

That's correct.

> Therefore it is dangerous to use the generic string type because in
> general a programer needs to know how the strings are stored, otherwise
> significant bugs are likely.

That goes for both shortstring and ansistring.

> With Shortsstrings you don't have to think
> about reference counters and other traps that can be cause hard to find
> errors (i.e. when using ansistrings within a highly nested data
> structure).

No problem what so ever. ansistrings are safe unless you much in the
internals on purpose.

> Just think of a array of strings. If shortsstrings are used, all data is
> in one block of memory

(and on average 75% too large)

> You can move it around and make copies of it. But
> with ansistring this is not so easy. You only have an array of pointers.

Assign them all of them, is a lot faster, since copy-on-write.

Seriously, there are basket cases where shortstrings are useful. But that
was not what this is about. In the general case, you should avoid them.