On 4/16/2013 5:07 AM, Antoon Pardon wrote:
Op 16-04-13 05:17, Terry Jan Reedy schreef:
On 4/15/2013 10:32 PM, Steven D'Aprano wrote:
On Mon, 15 Apr 2013 20:52:58 -0400, Terry Jan Reedy wrote:
I will keep the above in mind if I write or review a patch. here are 4
non-subclassable builtin classes. Two are already documented. Bool in
one, forget which other. I believe it was recently decided to leave
the other two as is given the absence of any practical use case.
Why should there be a practical use case here?
As a practical matter, the change is non-trivial. Someone has to be
motivated to write the patch to enable subclassing, write tests, and
consider the effect on internal C uses of slice and stdlib Python used
of slice (type() versus isinstance).
Since classes are in general subclassable,
if written in Python, but not if written in C.
I once had an idea of a slice-like class that I would have liked to
experiment with.
Did the idea actually require that instances *be* a slice rather than
*wrap* a slice?
--
Terry Jan Reedy
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