Re: Reading directory names with read-file-name

[storm@cua.dk (Kim F. Storm)]

Richard Stallman <rms@gnu.org> writes:

>     I've looked some more on this, and the file-name-handlers (e.g.  used
>     by ange-ftp) further complicates chaning the API for read-file-name,
>     read-file-name-internal, and file-name-all-completions, as well as
>     introducting a read-directory-name function.
> 
> How so?

My concern is that existing file-name-handlers for read-file-name
are written to match the current API for that function, and
they are expected to "mirror" the behaviour of read-file-name
for any given set of arguments.

Now, if we change the API for read-file-name, e.g. by changing
the interpretation of the MUSTMATCH argument or adding a PREDICATE
argument, the existing file-name-handlers may no longer work correctly.

And if I add a new read-directory-name function, the existing
file-name-handler for read-file-name will not be called when reading a
directory name; instead a new file-name-handler will be needed for
read-directory-name (which is simple), but the existing packages which
install file-name-handlers for read-file-name will need to be extended
with a file-name-handler for read-directory-name as well.

So it's not trivial to change the API...

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk