[fpc-devel] Unicode and UTF8String

Martin Friebe fpc at mfriebe.de
Mon Dec 1 22:50:11 CET 2008


Mattias Gaertner wrote:
> On Mon, 01 Dec 2008 15:06:45 +0000
> Martin Friebe <fpc at mfriebe.de> wrote
>> That would mean that in order to avoid conversation, some functions
>> of the RTL would be needed in overloaded versions for each string
>> type. IMHO this applies only to those, which do not (or not always)
>> make calls to the OS. Any other function does the conversation
>> anyway. (It will be a case by case base)
>>     
> Sorry, I can't follow here.
> Please enlighten me, why an overloaded function with an internal
> conversion is better than an implicit conversion?
>   
I made a difference between rtl function which will call OS functions 
(the one that would need to internally convert the format) and those 
that do not make OS calls (or do not always make them)

Yes I agree, and said so before: If a rtl function is going to pass on 
the data to the OS, and conversation is always needed, then no 
overloading is needed. Use RTLString.

If an function does not use the OS (e.g extract file-path or name) then 
no internal conversion is needed. Therefore overloaded functions would 
give benefit to some programmers. (to name one group: most beginners, 
who have more than enough to worry about; and will be glad if strings 
are kept simple to use ( a fixed known type, not a type that looks 
somehow abstract, because you do not know its implementation at the time 
you write your code)

>> [...]
>> Also it would be nice (so I do not know how) not to have to duplicate 
>> code, in order to archive this. Something like generics, maybe.
>>     
>
> The goal of RTLString is to avoid duplicate code in the RTL.
>   
Yes I acknowledged that this would be a problem. And also RTLString has 
the benefit, of allowing unicode fpc to be available far earlier than it 
would otherwise.

The question remains, could it then be extended/optimized? Maybe a 
generic like template (for functions, instead of objects)? Which needs 
to be written only once, and the will be specialized for each string type?

Best Regards
Martin



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