Re: Is there any elisp functions to tell whether the cursor is in a comment block?

[Lennart Borgman (gmail)]

Drew Adams wrote:
> > > > I am thinking about a page on EmacsWiki that holds the 
> > > > information. This page could for example have entries like
> > > >
> > > >    === Tabkey2.el 21=n 22=y 23=y ===
> > > >    elisp:tabkey2.el
> > > >    comment ... comment ...
> > > >
> > > > ELPA could then fetch information from this page. And 
> > > > users could too.
> > > >
> > > > The elisp pages on EmacsWiki could at the bottom have a link 
> > > > to this page.
> > > A file-header field in each library file can give the same 
> > > information. I use this field, for example:
> > >
> > >  ;; Compatibility: GNU Emacs 20.x, GNU Emacs 21.x, GNU Emacs 22.x
> > >
> > > However, the field value is free-form at present. A 
> > > conventional form would let tools pick up the value.
> > >
> > > An advantage is locality of reference and update: some 
> > > developers are more likely to update a file header field than
> > > a separate wiki page.
> > Yes, that might be good too, but it can't be used for packages.
>
> Why not?
>
> If a tool (e.g. ELPA) can pick up the info from a wiki page, as you suggest, why
> can't it pick it up from an elisp file (which can also be a wiki page) or a
> "package file" or whatever. IOW, whatever info you would provide in the form you
> suggested could alternatively be provided in the source code itself. No?

Yes, you are right. It can be done. For a package consisting of several 
files there can be a file, say this-package-compatibility.el, that 
contains this information.

For a single elisp file I think the compatibility info can be in the 
file itself.

So maybe your suggestion is better.

I would suggest a shorter version of the compatibility line, like

  ;; Compatibility: Emacs=20.*,21.*,22.* XEmacs=unknown

I would also suggest adding this information to all elisp files on 
EmacsWiki. Perhaps this can be done automatically using the dates the 
files where added and assuming the files only works for the then current 
released version of Emacs?