On 10/15/07, Guido van Rossum <[EMAIL PROTECTED]> wrote:
> On 10/15/07, Jim Jewett <[EMAIL PROTECTED]> wrote:
> > On 10/12/07, Guido van Rossum <[EMAIL PROTECTED]> wrote:
> > > On 10/12/07, Gregory P. Smith <[EMAIL PROTECTED]> wrote:
> > > > > > - add missing methods to PyBytes (for list, see the PEP and compare
> > > > > > to
> > > > > > what's already there)
> >
> > > > As I work on these.. Should the mutable PyBytes_ (buffer) objects
> > > > implement
> > > > the following methods inplace and return an additional reference to
> > > > self?
> >
> > > > .capitalize(), .center(), .expandtabs(), .rjust(), .swapcase(),
> > > > .title(),
> > > > .upper(), .zfill()
> >
> > > No... That would be a huge trap to fall in at all sorts of occasions.
> >
> > So would returning a different object. I expect a mutation operation
> > on an explicitly mutable object to mutate the object, instead of
> > creating something new.
> >
> > If it returns a new one, I can imagine doing something like:
> >
> > obj.inqueue=bytesbuffer(100)
> > obj.inqueue.lower() # oh, wait, that didn't really do anything
> > after all...
> > if obj.inqueue[:4] == b"http": # works on my *regular* input...
> >
> > Maybe the answer is "don't do that", and to only do this sort of
> > processing before it goes in the buffer or after it comes out, but ...
> > it still looks like a major gotcha.
>
> Since these methods with these very names already exist for strings
> and return new values there, I don't see the gotcha unless you never
> use strings.
Maybe .lower() should return immutable bytes, rather than mutable
buffer? For the use cases I can imagine this'd still work correctly,
and fits better with why it makes a copy. buffer is all about
operating in-place, so any copy immediately doesn't fit the buffer
concept.
obj.inqueue = bytesbuffer(100)
# replaces existing buffer contents. Temp copy need not be mutable
obj.inqueue[:] = obj.inqueue.lower()
if obj.inqueue[:4] == b"http":
obj.inqueue = bytesbuffer(100)
if obj.inqueue[:4].lower() == b"http": # compares bytes with bytes
--
Adam Olsen, aka Rhamphoryncus
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