Re: find-file-noselect needs save-match-data

[Stefan Monnier]

>> Actually, I'd even argue against any such new function,
> How about adding another optional argument then?

Same deal: you're trying to solve a non-problem.

>> on the grounds that it's solving a non-problem, i.e. it will just add new
>> functions, new code, new complexity for no real benefit.

> Consider `abbreviate-file-name'.  It has the following construct:

>       (if (and (string-match abbreviated-home-dir filename)
>              ;; If the home dir is just /, don't change it.
>              (not (and (= (match-end 0) 1)
>                        (= (aref filename 0) ?/)))
>              ;; MS-DOS root directories can come with a drive letter;
>              ;; Novell Netware allows drive letters beyond `Z:'.
>              (not (and (or (eq system-type 'ms-dos)
>                            (eq system-type 'cygwin)
>                            (eq system-type 'windows-nt))
>                        (save-match-data
>                          (string-match "^[a-zA-`]:/$" filename)))))
>         (setq filename
>               (concat "~"
>                       (match-string 1 filename)
>                       (substring filename (match-end 0)))))

Looks fine to me.  I don't find it particularly unreadable and its
efficiency seems to be perfectly adequate.


        Stefan


PS: By the way, the above code looks odd.  The comment seems to imply that
the MS-DOS check just reproduces the preceding / check, but it's not
the case: the / check makes sure that if HOME is / then /a/b will not be
changed to ~/a/b, whereas the MS-DOS check will only prevent changing A:/ to
~ but it will not prevent changing A:/b/c to ~/b/c.  I noticed this when
I considered replacing those two checks with

               ;; If the home dir is just /, don't change it.
               ;; Same thing for A:/ under FreeDOS.
               (let ((home (directory-file-name (match-string 0))))
                  (equal home (file-name-directory home)))