Re: Proposal: `buffer-offer-save' be made a permanent-local

[MON KEY <monkey@sandpframing.com>]

Kevin Rodgers wrote:
> Isn't it as easy as:
>
> (put 'nonpermanent-local-variable 'permanent-local t)

Yep, and therein lies the rub.

My major-mode did this instead:

(put 'deadweight-unless-you-look-for-me 'permanent-local t)

How does _your_ major-mode know to test for this permanent local?

And vice versa, how does _my_ major-mode know to test for
`nonpermanent-local-variable'?

Right now we rely on the scorched earth tactics of
`kill-all-local-variables' to resolve these sorts of ambiguities. IOW
we napalm the room to erase whatever farts the previous fella left
behind.  And, in general this approach has been a fairly effective
form of air freshener but doesn't cover up certain lingering odors:

,----
| As a special exception, local variables whose names have a non-nil
| `permanent-local' property are not eliminated by this function.
|
`---- (describe-function 'kill-all-local-variables)


If you find the existing approach above ugly then you may then agree
with the proposed solution to:

 a) elevate some symbol e.g. `buffer-offer-save' to a higher status

 b) teach your major-mode to check for this symbol (where applicable)

 c) hope everyone elses major-modes do this as well

 d) wait for Emacs to begin verbosely prompting you to save every last
    useless buffer you visited _before_ she will allow her process to
    terminate.

 e) Seek out the offending elisp code that did:

    (set (make-local-variable 'buffer-offer-save) t)

    i) Check in a coupla places 'cause the major-mode/code which first
        set the var may be two or three times removed.

 f) Having located the offending code fire off a disgruntled email to
    the responsible party asking why they thought it reasonable to
    reach into your Emacsen and toggle that variable in _your_ buffers
    without first asking if it was kosher to do so...

 g) Become increasingly baffled when said coder explains that while the
    property _was_ set by his code _you_ are wrong to be miffed b/c he
    assumed:

    "this is what most people expect.
     You are the corner case.
     Sorry 'bout that"

Good luck trying to explain to someone how it is that the real
exceptional special circumstance isn't your expectations but the
permanent local variable that keeps getting flipped behind your back
when you aren't looking.

--
/s_P\