Re: Instead of pcase

[Eli Zaretskii]

> Date: Fri, 01 Dec 2023 16:47:51 +0100
> From:  Michael Heerdegen via "Emacs development discussions." 
> <emacs-devel@gnu.org>
> 
> > My point focuses on the problems this syntax causes to someone who
> > doesn't have intimate knowledge and a lot of practice with pcase.
> 
> It is repeatedly used a wording like "magical", as if that was an
> argument.  Ok, this syntax makes one first wonder how it has to be
> interpreted.  Happened to me, too.  But this (the wondering) takes only
> seconds.  What happens after that?  Have people then seriously tried to
> understand the syntax?  Where and why did they fail?  I heard nothing
> about that.  Just a repetition that it looks "strange" or "magical" or
> that one would expect a different syntax.

You are asking me about what others have done.  I don't know.  I do
know that having understood this once doesn't mean one will remember
that the next time.  If the meaning is complicated enough, and the
next time is far enough from the previous one, one could simply
forget, and then will have to make the same effort understanding that
again.

> Given that cons cells and lists are fundamental building blocks of the
> whole language, I had hoped to hear more about why understanding this
> would be hard.  Nobody did that concretely apart from Richard.  And it
> might be the case that his rewrite will reuse the backquote syntax.

We shall see.

> > If one bumps into such constructs very frequently, then eventually one
> > will become familiarized with them.  But if the frequency is low
> > enough, one could easily forget the details, and then one will need to
> > consult the documentation again the next time.
> 
> What I want to say is that if you need to consult documentation of
> backquote syntax in pcase again and again, you might not have understood
> it entirely.  This is my question: do people fail to understand the
> concept, or don't they even try?

I'll let others answer this.  Me, I just want to tell that complicated
stuff frequently needs to be re-read several times before it sinks.
Especially if these time instances are far apart.