[Python-Dev] Re: [Distutils] Questions about distutils strategy

[Jean-Claude Wippler]

Guido van Rossum wrote:
> 
> [... my not-really-meant-as-rant about adopting zip as format ...]
>
[zip concatenation feature]

> How does this work?  Does that work for all zip tools, or just for the
> ZIP reader in Wrap?  (I looked up how Jim A does it -- his central
> directory at the end of the file contains the total size of the data
> covered by that directory, so he seeks back to the beginning of it and
> sees if another magic number precedes it; and so on.  Very simple.)

Same for Wrap.  Standard tools would not see the preceding ZIP groups.

In terms of maintenance, I'd avoid this trick.  I merely wanted to point
out that zip archives can be stacked, if the reader is set up to it.

> Question: does the wrap::open code go out to the regular filesystem
> if it finds there's no wrap archive?  That would be handy so you can
> test the code in its unwrapped form without change.

IIRC, Wrap overrides "open" for embedded entries as "file.zip/abc.py".
There's more being developed in this area: a "virtual file system" which
lets you mount archives and such (VFS by Matt Newman, mentioned with his
permission), so that the file-system model can be extended to navigate
into a lot more things than real file systems.

Andrew Kuchling's post hints at another tangent: opendir/readdir is of
course simply an enumeration.  There's a lot of "genericity" lurking in
scanning across file systems, trees, networks, and resources in general.

<minirant> The filesystem <-> OO dichotomy needs a review. </minirant>

> Python needs this too.

<voice location=in-the-desert level=timid>
Concepts like these have a lot to offer - and would make even more sense
if they were done in a way which benefits multiple scripting languages.
Feel free to reply by email if you ever want to further discuss this.
</voice>

-- Jean-Claude