[Python-Dev] [patch #100912] should we keep the \xnnnn escape in unicode strings?

[Fredrik Lundh]

mal wrote:

> There were objections from Finn Bock and myself: \xXXXX is
> defined to mean "read all hex chars until the next non-hex char
> and then cast to the underlying type (char or wchar_t)" in C9X.

finn wrote:=20

    "the implementation of \x in JPython is so full of bugs
    and inconsistencies that I'm +1 on your proposal."

since when is +1 an objection? ;-)

> Not that this definition is optimal, but we should stick to what
> the standard says and only depreciate usage of \xXXXX in favour
> of \uXXXX. Code using escapes like "\xABCD" which then results
> in "\xCD" is broken anyway -- having u"\xABCD" return "\uABCD"
> wouldn't make much of a difference (+ the bug would become pretty
> obvious if viewed in a Unicode aware viewer: Asian characters are
> very easy to recognize in ASCII text ;-)

as Tim pointed out in the SRE thread, the only standard that
means something here is Python 1.5.2.  And in Python 1.5.2,
\u means read as many hex digits as you can, and cast the
result to a character.

I'd say it's more important to be compatible with Python (1.5.2
string literals, SRE regular expression literals), than to be com-
patible with C9X...

</F>