typetesting, adaptation, typeclasses, ... (was Re: isinstance() considered harmful)

[Kragen Sitaker]

"Jason Orendorff" <jason at jorendorff.com> writes:
> > In MetaPy.Sugar.Sequence, I define everything in terms of
> > simple_getitem, simple_setitem, simple_delitem, insert, and __len__.
> > [...]
> > append is defined in terms of extend [...]
> 
> Wouldn't this be better?
> 
>   def append(self, obj):
>       self.insert(self.__len__(), obj)

Maybe so.  I can't really imagine a case where it would be noticeably
worse.