tags 13281 patch
quit

"Drew Adams" <drew.adams@oracle.com> writes:

>  
> 1. Node `Package-Requires' says that this file-header field must be a
> list of lists, each of whose cadr is a version number (string).  IOW,
> the version number seems to be mandatory: it must be present.

It's not mandatory, I've clarified this in the patch below.
  
> 2. It does not say how these version-number strings are compared,
> rendering this spec of the field almost meaningless.  `string-lessp'?
> `version<'?  `version<='?

I added a mention of `version-to-list' in the patch.  Along with the
existing text saying "the minimum acceptable version number" I think
that makes the meaning clear.

  
> What is the relation between this `Version' "attribute" and the
> file-header `Version' field?  None?  Where does the attribute value come
> from, if not from that field?  No info at all about this.

`(elisp) Simple Packages' says

    The package's attributes are taken from the various headers

`(elisp) Multi-file Packages' says

       One of the files in the content directory must be named
    `NAME-pkg.el'.  It must contain a single Lisp form, consisting of a
    call to the function `define-package', described below.  This defines
    the package's version, brief description, and requirements.

I added the word "attributes" to the last sentence in the patch.  I
think that makes it clear.

>  
> 4. #3 means that a library must use a version number that is
> recognizable by `version-to-list'.  And what if it does not - what
> happens?  How to refer to a required library, using `Package-Requires',
> if that required library does not have a `Version' file-header entry
> that corresponds to `version-to-list'?

`(elisp) Simple Packages' says

       The version number comes from the `Package-Version' header, if it
    exists, or from the `Version' header otherwise.  One or the other
    _must_ be present.
  
> 5. Why does a package need to be released in "releases", each of which
> is accompanied by an increase in the version number?  And is it really
> even true that this is a hard requirement?

I added an explanation in the patch about why it's needed.

>  
> This does not seem to be a requirement for multiple-file packages.  Why
> should it be a requirement for single-file packages?
>  
> I know it is not required for multi-file packages because I have some
> that work fine with MELPA etc., and their `Version' numbers are not
> incremented each time the package files are uploaded, which is daily
> (automatically).

This doesn't cover MELPA though.  MELPA automatically adds a version
number based on the timestamp of when the source is retrieved.  The
manual does not document MELPA as it is not part of GNU Emacs.
  
>  
> And what about inherited dependencies?  If hl-line+.el requires
> hl-line.el, do I need to flatten the `Package-Requires' for
> crosshairs.el, to include hl-line?

No.  I added the word "recursively" to the "Dependencies"
attribute description in the patch.
  
> And what if the list of dependencies is long - do I need to write them
> all on a single line, making the line-width far too wide for the file?
> If not, what do `Package-Requires' continuation lines look like?

It must be on a single line.  I've added a mention about that in the
patch.