unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
From: "Stephen J. Turnbull" <stephen@xemacs.org>
To: Stephen Leake <stephen_leake@stephe-leake.org>
Cc: emacs-devel@gnu.org
Subject: Re: C-x C-e on numbers
Date: Fri, 05 Dec 2014 15:53:36 +0900	[thread overview]
Message-ID: <877fy6lh8v.fsf@uwakimon.sk.tsukuba.ac.jp> (raw)
In-Reply-To: <85oarjnyzx.fsf@stephe-leake.org>

Stephen Leake writes:

 > M-: (show-binary 42)

(defun show-binary (n)
  "Documentation left as exercise for the reader."
  ;; hexadecimal version also an exercise
  (let ((s (format "%o" n)))
    ;; loop unrolled for creativity conservation
    (setq s (replace-in-string s "0" "000"))
    (setq s (replace-in-string s "1" "001"))
    (setq s (replace-in-string s "2" "010"))
    (setq s (replace-in-string s "3" "011"))
    (setq s (replace-in-string s "4" "100"))
    (setq s (replace-in-string s "5" "101"))
    (setq s (replace-in-string s "6" "110"))
    (setq s (replace-in-string s "7" "111"))
    ;; stripping leading zeros or padding to wordsize, more homework
    (concat "#b" s)))

Seriously, does this function really need to be particularly efficient?




  reply	other threads:[~2014-12-05  6:53 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-04 15:56 C-x C-e on numbers Alfred M. Szmidt
2014-12-04 16:27 ` Andreas Schwab
2014-12-04 16:47 ` Stephen Leake
2014-12-05  6:53   ` Stephen J. Turnbull [this message]
2014-12-05  7:04 ` Stefan Reichör

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

  List information: https://www.gnu.org/software/emacs/

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

  git send-email \
    --in-reply-to=877fy6lh8v.fsf@uwakimon.sk.tsukuba.ac.jp \
    --to=stephen@xemacs.org \
    --cc=emacs-devel@gnu.org \
    --cc=stephen_leake@stephe-leake.org \
    /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 public inbox

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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).