Typed directories

[Gregory Merchan <merchan phys lsu edu>]

I've seen that for various kinds of directory metadata using files inside
a directory has been rejected because of performance. For example, it
was suggested that the desktop direcotry's name be localized according to
the contents of a dot-file in the directory. Because schemes like this would
require looking into every directory and reading a file, performance would
be miserable in directories containing many subdirectories.

I would like to take a cue from NeXT (or MacOS X) and have such a facility
for a limited set of directories. It seems that NeXT doesn't consider files
for metadata in a directory unless the directory has a special name. For
example, if the directory is an application, and thus contains an information
property list, its property list is only read if the directory's name ends
in ".app".

I'm not sure it works that way, as I've never used such a system, but that
seems like a scheme that could be useful and avoid the performance penalty.

A few implementation questions come to mind:
  Should all dotted name directories be checked for internal metadata?
  Should only recognized dotted name directories be checked?
  How would dotted names be recognized?
  What would be the format of the metadata?

I think only recognized dotted name directories should be checked. Recognition
should be handled through the existing MIME system, if possible.

Because NeXT, GNUStep, and MacOSX are such close kin, I think we should use a
compatible metadata system. There's also the benefit of thorough existing
documentation.

I hope those who have used bundles (typed directories) will attest to their
merits and help bring a similar, at least compatible, system to GNOME.

Cheers,
Greg