[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: pcase defuns
From: |
Richard Stallman |
Subject: |
Re: pcase defuns |
Date: |
Thu, 31 Mar 2022 00:27:10 -0400 |
[[[ To any NSA and FBI agents reading my email: please consider ]]]
[[[ whether defending the US Constitution against all enemies, ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]
> The way I look at it, it does do this, but it's just structured
> differently. The normal defun as one arglist. Mine has one per
> matching clause, which means that it can take a variety of
> different arguments, all matching. And the arglist and the
> matching clauses are the same thing, so the arglist can be (n), or
> ('foo n), or (1 2 (3 n)), etc. Yes, it's weird, but I think the
> differentiation here is useful, see my next point.
The argument list is not just a concept in users' minds.
The command C-h f, which shows documentation for a function,
displays the function's argument list. If you try C-h f cons RET,
you'll see what I mean.
See also `func-arity'.
So there is a practical reason for defining constructs to
set up the function's argument list.
> In particular, with your
> proposal, we lose the ability to have fairly different arg
> patterns, with different numbers of args, or different
> destructuring patterns.
Not necessarily. You could specify `&rest args' for an arglist that
conveys no information. But users find it useful to see in a simple
way what the arguments of the function should be.
--
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)