all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
From: "Drew Adams" <drew.adams@oracle.com>
To: "'Matt Price'" <moptop99@gmail.com>
Cc: help-gnu-emacs@gnu.org
Subject: RE: basic help evaluating function in an alist
Date: Sat, 1 Dec 2012 19:44:53 -0800	[thread overview]
Message-ID: <B5A7126D12854BFF89F76BDE5D6B1A4C@us.oracle.com> (raw)
In-Reply-To: <CAN_Dec-jh0HAF1i4PppCWkKRGz0d-Rf6tULDMhs=xcngbYaxFg@mail.gmail.com>

> > '(guide . (selected-window))
> >
> > (cons 'guide (selected-window))
>
> I still don't quite understand what it is in the
> syntax that causes the function (selected-window) to be evaluated in
> one case and not the other

In the first case, the dotted pair `(guide . (selected-window))' is quoted.
When evaluated, the sexp `(quote (guide . (selected-window)))' returns that
dotted pair: `(guide . (selected-window))'.  `quote' returns its argument
without evaluating it.

In the second case, the sexp `(cons 'guide (selected-window))' is evaluated,
which means applying function `cons' to its two arguments, after evaluating each
of them.

Evaluation of the first argument, which is `(quote guide)', returns the symbol
`guide'.  Evaluation of the second arg, `(selected-window)', returns the
selected window.  Function `cons' then creates a cons cell whose car is the
symbol `guide' and whose cdr is that window.




  reply	other threads:[~2012-12-02  3:44 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-01 22:57 basic help evaluating function in an alist Matt Price
2012-12-01 23:12 ` Drew Adams
2012-12-02  2:40   ` Matt Price
2012-12-02  3:44     ` Drew Adams [this message]
2012-12-04 14:41       ` Matt Price
     [not found] <mailman.14266.1354402640.855.help-gnu-emacs@gnu.org>
2012-12-01 23:12 ` WJ
2012-12-02  1:06   ` WJ

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=B5A7126D12854BFF89F76BDE5D6B1A4C@us.oracle.com \
    --to=drew.adams@oracle.com \
    --cc=help-gnu-emacs@gnu.org \
    --cc=moptop99@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/emacs.git
	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.