Re: [Emacs-diffs] master 4d3a595: `load-path' should contain only directory names

[Random832]

Stefan Monnier <address@hidden> writes:
> The problem here is in the manual: "directory name" is a general term
> used in the POSIX world and beyond, and it usually doesn't care whether
> there's a trailing slash.  There are a few particular situations where
> the difference matters, indeed, but rather than co-opt the generally
> known term and load it with a more precise semantics than is usual, I'd
> prefer that we introduce new names for "directory name with a slash" and
> "directory name without a slash".

I think the intent of the existing documentation is that a so-called
"directory name" is the one that may be concatenated to a filename to
form a path. For example, on VMS:
  DKA0:[MYDIR.SUBDIR1.SUBDIR2]        would be the "directory name"
  DKA0:[MYDIR.SUBDIR1]SUBDIR2.DIR;1   would be the "directory filename"

Maybe this should be called a "directory prefix"? I don't think you can
concatenate it to a relative path other than a simple filename on VMS
though. What _do_ (or did) these functions do on VMS or other systems
with exotic path formats (Risc OS?), if any are (were ever) supported?

I wonder, what Emacs does (or did) on classic MacOS. There, relative
pathnames started with a separator (:foo = foo in cwd) and absolute ones
did not (HD:foo == foo in root of HD volume). Doubling a path separator
would be interpreted as the parent directory (::foo == ../foo)

Logic would dictate, therefore, that both the "directory name" and
"directory filename" would not end with a colon, and that it would
only be valid to concatenate if you have a relative path (one that does
begin with a colon).