[Python-Dev] PEP 263 considered faulty (for some Japanese

[Stephen J. Turnbull]

>>>>> "Fredrik" == Fredrik Lundh <fredrik@pythonware.com> writes:

    Fredrik> Stephen J. Turnbull wrote:

    >> By the way, where others in this thread have similar
    >> experience, it would be helpful if they could refer to previous
    >> implementations similar to PEP 263.

    Fredrik> XML.

Not similar enough.  There is a big difference between a spec which
states

    Definition: A parsed[1] entity contains text, a sequence of
    characters, which may represent markup or character data.
    Definition: A character is an atomic unit of text as specified by
    ISO/IEC 10646. Legal characters are tab, carriage return, line
    feed, and the legal characters of Unicode and ISO/IEC 10646.

and PEP 263, which deliberately avoids any such declaration.  There is
a big difference between a spec which refers to "different encodings
of characters" which are to be treated by the parser as a sequence of
ISO/IEC 10646 characters, and PEP 263 which specifies parser behavior
with respect to the stream of externally encoded entities.

Note well, these are the differences that I have claimed are likely to
cause trouble for Python if PEP 263 is adopted as is.

    Fredrik> PEP 263 implements the same model, minus UTF-16, and with
    Fredrik> a two-phase implementation plan.

It does not.

    Fredrik> nothing new here.

True.  But the historical antecedent for PEP 263 is much closer to
Emacs/Mule, which comes down on the PEP 263 side of both the issues
identified above, than to XML.

In fact, I described (without being familiar with the XML spec until
you mentioned it) something very close to the XML specification, and
an implementation which gives the same practical benefits as PEP 263.


Footnotes: 
[1]  I am not an XML expert, but as far as I can tell, "parsed entity"
refers to the fact that before it may be used it must be parsed, not
to some kind of transformation of the entity, which is then submitted
to the XML processor.  Ie, the restrictions in section 4 refer to the
data as stored externally, just as PEP 263 does.

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