Ceci n'est pas une char

[kris]

Walter Bright wrote:
> Thomas Kuehne wrote:
> 
>> Challenge:
>> Provide a D implementation that firsts converts to UTF-32 and has
>> shorter runtime than the code below:
> 
> 
> I don't know about that, but the code below isn't optimal <g>. Replace 
> the sar's with a lookup of the 'stride' of the UTF-8 character (see 
> std.utf.UTF8stride[]). An implementation is std.utf.toUTFindex().


It's not as simple as that any more. Lookup tables can sometimes cause 
more stalls that straight-line code, especially with designs such as the 
P4. Not to mention the possibility of a bit of cache-thrashing with 
other programs.

Thus, the lookup may be sub-optimal. Quite possibly less optimal.