>> So what if the unicode string doesn't start with an XML declaration?
>> Will it add one?
>
> No.
Ok. So the XML document would be ill-formed then unless the encoding is
UTF-8, right?
> The point of this code is not just to return whether the string starts
> with "<?xml" or not. There are actually three cases:
Still, it's overly complex for that matter:
> * The string does start with "<?xml"
if s.startswith("<?xml"):
return Yes
> * The string starts with a prefix of "<?xml", i.e. we can only
> decide if it starts with "<?xml" if we have more input.
if "<?xml".startswith(s):
return Maybe
> * The string definitely doesn't start with "<?xml".
return No
>> What bit fiddling are you referring to specifically that you think
>> is better done in C than in Python?
>
> The code that checks the byte signature, i.e. the first part of
> detect_xml_encoding_str().
I can't see any *bit* fiddling there, except for the bit mask of
candidates. For the candidate list, I cannot quite understand why
you need a bit mask at all, since the candidates are rarely
overlapping.
I think there could be a much simpler routine to have the same
effect.
- if it's less than 4 bytes, answer "need more data".
- otherwise, implement annex F "literally". Make a dictionary
of all prefixes that are exactly 4 bytes, i.e.
prefixes4 = {"\x00\x00\xFE\xFF":"utf-32be", ...
..., "\0\x3c\0\x3f":"utf-16le"}
try: return prefixes4[s[:4]]
except KeyError: pass
if s.startswith(codecs.BOM_UTF16_BE):return "utf-16be"
...
if s.startswith("<?xml"):
return get_encoding_from_declaration(s)
return "utf-8"
Regards,
Martin
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
http://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
