On Tue, May 27, 2008 at 12:42:48PM -0700, Guido van Rossum wrote: > [+python-3000] > > On Tue, May 27, 2008 at 12:32 PM, Armin Ronacher > <[EMAIL PROTECTED]> wrote: ... > > A problem comes up as soon as user defined strings (such as UserString) is > > passed to the function. In my opinion a good solution would be a "String" > > ABC one could test against. > > I'm not against this, but so far I've not been able to come up with a > good set of methods to endow the String ABC with. Another problem is > that not everybody draws the line in the same place -- how should > instances of bytes, bytearray, array.array, memoryview (buffer in 2.6) > be treated? > > -- > --Guido van Rossum (home page: http://www.python.org/~guido/)
The issue goes beyond iterability. If a user defined string such as UserString that is not derived from one of the "true" builtin string types is passed to a builtin function that expects a string it will be rejected. PyArgs_ParseTuple discriminates against such user defined types :-) If a String ABC is implemented it could be used as a signal that the object is not just convertable to a string (virtually all objects are) but IS a string and its __str__ should be used during builtin function argument parsing. - Oren _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
