From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: New library num-base-converters Date: Tue, 15 Aug 2017 11:24:05 -0400 Message-ID: References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1502810717 2303 195.159.176.226 (15 Aug 2017 15:25:17 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 15 Aug 2017 15:25:17 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Aug 15 17:25:12 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dhdiM-0008Oz-0b for ged-emacs-devel@m.gmane.org; Tue, 15 Aug 2017 17:25:06 +0200 Original-Received: from localhost ([::1]:41225 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dhdiS-0005cR-K8 for ged-emacs-devel@m.gmane.org; Tue, 15 Aug 2017 11:25:12 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43351) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dhdhk-0005au-7H for emacs-devel@gnu.org; Tue, 15 Aug 2017 11:24:29 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dhdhf-0002dB-7j for emacs-devel@gnu.org; Tue, 15 Aug 2017 11:24:28 -0400 Original-Received: from [195.159.176.226] (port=48769 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dhdhf-0002cs-0m for emacs-devel@gnu.org; Tue, 15 Aug 2017 11:24:23 -0400 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1dhdhS-0005Pb-70 for emacs-devel@gnu.org; Tue, 15 Aug 2017 17:24:10 +0200 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 29 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:eLLatvE/N3zBnNgkO8kvYRU2Xzg= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:217569 Archived-At: >>> +(defun nbc-number-base-converter (num base-in base-out) >>> + "Translate NUM, a string representing an integer, to a different base. >>> +BASE-IN, an integer, is the basis of the input NUM. >>> +BASE-OUT, an integer, is the basis to display NUM." >> Having a string as both input and output is a bad API, I think. > It's better API than not having API at all; it provides me the flexibility > to handle input as '0xff', '#xff' or 'ff'. Not that bad. What do you mean by "handle"? It only lets you convert the string to a string in a different base, which is rarely what you need. Instead you will generally want to extract the number it represents, then modify it a bit than turn it back into a string in a given base. >> All one needs is basically to add a `base` arg to number-to-string >> (there's already one for string-to-number). > Then we are again limited to 2 < b < 16 bases. No. We can similarly extend string-to-number to accept bases > 16. If you want to provide it without changing Emacs's core, you can make it a package that exports -string-to-number and -number-to-string, but the API should separate the conversion from a string to a number and back, rather than force you to conversions between strings, which force you to do things like "baseN-to-dec, then string-to-number, do something, then number-to-string, then dec-to-baseN", which is just silly (and inefficient to boot). Stefan