[chimera-dev] compression

[Eric Pettersen]

I've been thinking a little more about using compressed files.  How 
about this:

Current OpenSave functions would continue to work much as they do now, 
except that appropriate .gz files would also be listed in the browser, 
and possibly returned in the list of paths.  Instead of opening 
returned paths with the built-in open, you would instead use a function 
in OpenSave (osOpen?) that would check for possible compression and 
return an appropriate file-like object.

For contexts where an uncompressed file path is needed (e.g. handing 
off to PDBio [for now]), there would be another function in OpenSave 
that takes a path and returns a corresponding path to a uncompressed 
file [a no-op if the file was already uncompressed].  Any temporary 
uncompressed files would automatically be deleted on APPQUIT.

Opinions?

--Eric