bug#17871: 24.4.50; (elisp) `Core Advising Primitives': interactive spec as function?

[Drew Adams <drew.adams@oracle.com>]

> >> (advice-add 'compose-mail :around #'my-compose-mail-advice)
> >
> > That's a good example.  I've now added it to the trunk with some
> > slight modifications.
> 
> Thanks (and let me use this opportunity to express sincere admiration
> and gratitude for your general bug slaying performance and stamina).
> 
> If that really improves the substance of this bug report only Drew can
> say I guess.
> 
> I for one still think that a more detailed explanation similar to
> Michael's from a previous mail[1] would be helpful, ideally with more
> examples.

+1.

The example will help, no doubt.  But it would also
help to explicitly point out that this use (for
advice) of `interactive' is not the usual one.

What Michael said here:

  Although we can with nadvice use the same syntax
  for defining pieces of advice as for defining functions,
  advices have a different meaning (semantic).  The
  interactive specs of advices are not exactly interactive
  specs in the common sense - although they look similar,
  they are related, but different features.

  I think a short example would be good.  Also, the term
  "function" is a bit unclear here, maybe we should add
  "a lambda expression or fbound symbol" or so, to make
  clear that we don't mean a sexp that returns a function.

> And although I have managed to clarify a few points myself thanks to
> this conversation, my personal conundrum[2] remains unanswered: why
> does a simple advice have no effect on the interactive spec of the 
> function being advised, and is that really a feature? But perhaps
> that's for another thread.

Yes.