Re: ewoc patch

[Stefan Monnier]

> I like the ewoc package, but I found it somewhat inflexible.  I am
> submitting this diff (attached) in the hope of improving it.

> In particular:

>  * ewoc always wants every entry to be separated from the other
>    entries by a newline.

>  * It does not work properly with blank entries.  These become a real
>    problem when a blank separator is allowed.  Nodes often get printed
>    out of order.

Not sure what you mean by "blank" entries.  If you mean entries which
don't get printed (i.e. "invisilbe" entries), then yes, it's
a limitation that it would be good to lift.  IIUC you lift it by:

> * Design: Nodes that have no text have no start marker.

which I think is a good solution (when I tried to lift that limitation
it didn't occur to me, so I tried to manually separate the markers that
needed to move from those that needed to stay put and it was messy).

>  * ewoc-map is slightly misnamed; it doesn't map, it's more like
>    for-each.

It's the historical name.  To fit with other macros (like dotimes,
dolist), we could call it ewoc-do rather than ewoc-foreach.

>  * Added a version number.  I didn't have much to go on, so I just
>    said it was "2.0".  I will gladly change it to correspond to an
>    official version number.

The Emacs package generally doesn't like version numbers, so I'd rather
not introduce one here, unless there's really a good reason for it.

>  * Added a new field to the ewoc, "separator".  That's the string that
>    separates entries.  It defaults to "\n".

IIUC it can also be the empty string, right?  IIUC, the current ewoc.el
already makes it possible to get rid of the separator.  Making it
an argument might be a good idea as well.

> Testing:

>  * Created a test suite.  The suite relies on rtest, which
>    unfortunately is still between releasable versions.

We still don't have a testsuite in Emacs, but we'll gladly add the
testsuite to our repository (we have a `test' subdirectory for that).

> diff -c -b /home/tehom/emacs-21.4/lisp/emacs-lisp/ewoc.el 
> /home/tehom/projects/emtest/lisp/viewers/ewoc.el
> --- /home/tehom/emacs-21.4/lisp/emacs-lisp/ewoc.el    2001-07-16 
> 08:22:59.000000000 -0400
> +++ /home/tehom/projects/emtest/lisp/viewers/ewoc.el  2009-12-08 
> 22:57:46.000000000 -0500
> @@ -129,6 +129,8 @@
 
Emacs-21.4 is rather old.  ewoc hasn't seen much development, but it's
still substantially different.  Could you try and adapt your changes to
our latest code?


        Stefan