If invalid string should crash(was:string need to be robust)

[spir]

On 03/14/2011 07:55 AM, ZY Zhou wrote:
> Thank you Jussi,
>
> But still this is not part of the standard, U+FFFD is a commonly used approach,
> while the U+DC80..U+DCFF is also a common solution for
> that(http://en.wikipedia.org/wiki/Utf8#Invalid_byte_sequences), different approach
> solve different problems.

I am surprised of some of your very affirmative statements (all along the 
thread). None of the string processing libs I have met use the approach you 
propose here, which is replacing invalid input by other invalid data (surrogate 
values). On the other hand, the replacement character (0xFFFD) evoked by Jussi 
(which I also proposed in a previous post) is a valid Unicode code point; same 
for free user-avalable areas.

> I think the current problem in D is that std.utf module is ill defined, it's not
> designed to make developer's life easier. It just make the developers to ignore
> the case that utf8 string can be invalid.

On the contrary, D perfectly deals with invalid input by signalling it to you 
programmer. It is not ignored, which would be the worse approach. What to do 
with invalid input belongs to your application's logic (as pointed by 
Jonathan); you are demanding D standard libs to do your job at your place, 
exactly the way you want it, using an incorrect approach.

Denis

> --ZY Zhou
>
> == Quote from Jussi Jumppanen (jussij at zeusedit.com)'s article
>> %u Wrote:
>>> I agree with a), but not b), Can't find anything in unicode standard says
>>> you can use the low surrogate like that
>> According to: http://www.cl.cam.ac.uk/~mgk25/
>>      According to ISO 10646-1:2000, sections D.7 and 2.3c, a device
>>      receiving UTF-8 shall interpret a "malformed sequence in the same way
>>      that it interprets a character that is outside the adopted subset" and
>>      "characters that are not within the adopted subset shall be indicated
>>      to the user" by a receiving device. A quite commonly used approach in
>>      UTF-8 decoders is to replace any malformed UTF-8 sequence by a
>>      replacement character (U+FFFD), which looks a bit like an inverted
>>      question mark, or a similar symbol.
>> Refer to this file for the above quote:
>> http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt
>

-- 
_________________
vita es estrany
spir.wikidot.com