Re: [GNU ELPA] New package: tam

[Lynn Winebarger]

On Mon, Sep 18, 2023 at 1:02 PM Philip Kaludercic <philipk@posteo.net> wrote:
> > Apologies, I renamed the library to tam.el and failed to note the
> > changes I made to the renamed file did not get committed and pushed.
>
> So what does that mean?

That I don't use git enough to avoid rookie errors? I had already
addressed some of the items you brought up in my working copy, they
just hadn't been committed and pushed to the server.
I think I've addressed all the items you brought up in the last
version I pushed.

> I am the kind of person who thinks twice about installing a package when
> it has dependencies.  But if you prefer to use a package available on
> ELPA, then that is of course OK as well.

I revised it to make use of cl-loop per your observation in the
previous email.  I'm not really a fan of the loop imperative DSL, but
this case was simple enough (as you pointed out).
Some packages (like queue) provide pretty basic data structures, so I
think avoiding packages that depend on them only encourages
reimplementing the wheel.
However, I might be the world record holder for the number of elisp
libraries loaded and included in a dump file.
> >> -(defsubst tam-table-size (tbl)
> >> +(defsubst tam-table-size (tbl)         ;why not `defalias'
> >
> > I tried defalias first, but got a byte-compiler error about a void
> > variable.  Which I found confusing, since it should be looking for a
> > function definition, not a variable.  I'm using 28.3.
> > Some of the following should have already been fixed from when I ran 
> > checkdoc.
>
> What did you do?  That sounds like something was misquoted:
>
> (defalias 'tam-table-size #'tam--table-size)

I forgot defalias is a function and not a macro.  Thanks.

> >                                                             I'll
> > change it if required, but I find computing the place inside a set
> > form to be disconcerting if it's not required.  For example, I
> > wouldn't use a set form like
> > (set (if P 'A 'B) some-value)
> > in place of
> > (if P (setq A some-value) (setq B some-value))
>
> In that case, is there a reason you are using setf?

I'm confused - the documentation does not indicate that an "if" form
would be a "place" that setf knows how to handle.  The cl-lib doc does
say it extends setf to handle macro expansions, but 'if' is a special
form that does not macro-expand.
I use setf because that's the cleanest way to set fields of a
structure.  It's more like setq than set (it's a macro for one thing)
as far as I can tell.

> > I do want to return lists reflecting the ordering of the slots.  I am
> > not a fan of constructing an ordered structure only to reverse it.
>
> FWIW this is standard practice, and what a cl-loop with collect would
> also expand to.  And if I am not mistaken, this is more efficient, than
> accumulating a linked list in the right order to begin with (it is a
> difference of O(n) vs O(n^2), I believe).

Wait, did you mean cl-loop with collect will do the nreverse?  I
thought you meant it would keep track of the tail of the list and
update it.
Accumulating a list in the right order is only O(n^2) if you only keep
the head of the list.  The queue structure (or what I would write with
let-bound variables) holds a reference to the last cons cell of the
list to use in adding an entry on the end.  It's probably negligible
for very short lists, but it's just bad form.

> > That said, these functions are primarily intended for debugging.
>
> Wouldn't that kind of a convenience be an argument against adding an
> extra dependency?

Only if I was trying to get a library included in startup.el, or if
the dependency was not in GNU ELPA.  Otherwise, why are people writing
packages?  They are not all stand-alone user interfacing programs.
Some are just basic data structures and algorithms that haven't been
included in core emacs for whatever reason.  Queue is one of those.

Lynn