[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Replace trivial pcase occurrences in the Emacs sources
From: |
Eli Zaretskii |
Subject: |
Re: Replace trivial pcase occurrences in the Emacs sources |
Date: |
Thu, 01 Nov 2018 06:14:30 +0200 |
> From: Michael Heerdegen <address@hidden>
> Cc: address@hidden, address@hidden, address@hidden
> Date: Wed, 31 Oct 2018 21:41:01 +0100
>
> (defun second-elt-is-positive-p (l)
> (pcase l
> (`(,_ ,(pred (< 0)) . ,_) t)))
>
> (second-elt-is-positive-p (list 1 2 3))
> ==> t
>
> (second-elt-is-positive-p (list 1 -2 3))
> ==> nil
>
> Is the pattern `(,_ ,(pred (< 0)) . ,_) destructuring or does it
> additionally have to bind at least one variable to be called like that?
I think we have a destructuring here, since elements of a list are
extracted and assigned to the elements of the pattern. What we do
with the extracted elements (ignore 2 of them and apply a predicate to
the 3rd) is not really important for the purposes of this discussion.
- Re: Replace trivial pcase occurrences in the Emacs sources, Eli Zaretskii, 2018/11/01
- Re: Replace trivial pcase occurrences in the Emacs sources, Garreau\, Alexandre, 2018/11/01
- Re: Replace trivial pcase occurrences in the Emacs sources, Eli Zaretskii, 2018/11/01
- Re: Replace trivial pcase occurrences in the Emacs sources, Garreau\, Alexandre, 2018/11/01
- Re: Replace trivial pcase occurrences in the Emacs sources, Eli Zaretskii, 2018/11/01
- Re: Replace trivial pcase occurrences in the Emacs sources, TEIRLLM, 2018/11/01
- Re: Replace trivial pcase occurrences in the Emacs sources, Richard Stallman, 2018/11/02
- Re: Replace trivial pcase occurrences in the Emacs sources, Nix, 2018/11/04
- Re: Replace trivial pcase occurrences in the Emacs sources, Garreau\, Alexandre, 2018/11/04
- Re: Replace trivial pcase occurrences in the Emacs sources, TEIRLLM, 2018/11/01