[fpc-devel] for-in-index loop

[Michael Schnell]

On 01/25/2013 11:12 AM, Michael Van Canneyt wrote:
>
> Pchar ?
>
You seem to miss my point: the n'th printable character in an utf-8 
coded string (may same be stored as a pchar or a string) starts at the 
m'th byte (m>=n).

To find m for a given n you need to scan all bytes < m.

Thus a loop such as

for I = 1 to 100000 do begin
   n = Integer (random(100000));
   c = myString[n];
end;

Is rather fast with ANSI coded Strings.

When myString is coded in utf-8, it obviously provides silly code byte 
instead of printable characters, and replacing the term myString[n] by a 
straight forward  function searching for the n'th printable character 
will be very slow.

-Michael