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From: Daniel Brockman <daniel@brockman.se>
To: emacs-devel@gnu.org
Subject: Re: Calc: `*' binds more strongly than `/'
Date: Thu, 19 Apr 2007 04:58:34 +0200	[thread overview]
Message-ID: <87y7kpax45.fsf@wigwam.brockman.se> (raw)
In-Reply-To: 873b2xz6t9.fsf@totally-fudged-out-message-id

Christian Schlauer <cs-muelleimer-rubbish.bin@arcor.de> writes:

> But then I say that writing A/B*C and interpreting it like (A/B)*C
> saves me the trouble of typing in parentheses

Not really.  You could just type that as A*C/B.

The point is that the reduced precedence of `/' allows you
to always put all numerator factors before the slash and all
denominator factors after it, which is often very convenient.

(You could make the same argument for `+' and `-' --- i.e.,
that `A-B+C' should mean `A-(B+C)'.  However, this is not as
natural because one usually does not think of sums as units.
Writing `A-B-C' is completely natural, but `A/B/C' is not
completely natural --- in fact, it is a little confusing.)

I think this is good notation, but I also think that it
would be a good idea to warn the user and make sure that
they know what they are doing when entering such things.

Just make the warning easy to disable and all is well?

Those are my two cents.

-- 
Daniel Brockman <daniel@brockman.se>

  reply	other threads:[~2007-04-19  2:58 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-14 11:57 Calc: `*' binds more strongly than `/' Christian Schlauer
2007-04-14 15:09 ` Jay Belanger
2007-04-15 19:21   ` Chong Yidong
2007-04-15 20:05     ` Stefan Monnier
2007-04-17 12:47       ` Randal L. Schwartz
2007-04-17 18:03         ` Stefan Monnier
2007-04-18  8:44           ` Kim F. Storm
2007-04-18 19:27             ` Stefan Monnier
2007-04-18 20:02               ` Davis Herring
2007-04-18 20:16                 ` David Kastrup
2007-04-18 21:43                   ` Davis Herring
2007-04-19 16:10                 ` Stefan Monnier
2007-04-20 11:13                   ` Randal L. Schwartz
2007-04-20 13:40                     ` Stefan Monnier
2007-04-20 14:07                       ` Jay Belanger
2007-04-22  1:31                         ` Miles Bader
2007-04-22 10:19                           ` Christian Schlauer
2007-04-22 10:23                         ` Christian Schlauer
2007-04-22 19:47                           ` Jay Belanger
2007-04-23 10:46                           ` Jason Rumney
2007-04-23 13:03                             ` Kim F. Storm
2007-04-23 15:54                               ` Jay Belanger
2007-04-25 19:56                                 ` Christian Schlauer
2007-04-25 20:54                                   ` Jay Belanger
2007-04-26  3:35                                     ` Stefan Monnier
2007-04-26  4:06                                       ` Jay Belanger
2007-04-26 14:11                                         ` Stefan Monnier
2007-04-26 21:07                                           ` Christian Schlauer
2007-04-26 15:07                                         ` Davis Herring
2007-04-26 16:01                                           ` Stefan Monnier
2007-04-26 18:32                                             ` Luc Teirlinck
2007-04-26 21:29                                               ` Christian Schlauer
2007-04-26 23:17                                                 ` Luc Teirlinck
2007-04-26 21:07                                     ` Christian Schlauer
2007-04-27  1:27                                       ` Jay Belanger
2007-04-26 17:47                                   ` Davis Herring
2007-06-20 15:23                         ` Jay Belanger
2007-06-20 16:02                           ` Kim F. Storm
2007-06-20 17:13                             ` Jay Belanger
2007-06-20 17:29                             ` Luc Teirlinck
2007-06-20 17:54                               ` Jay Belanger
2007-06-20 19:14                                 ` Kim F. Storm
2007-06-20 19:28                                 ` Luc Teirlinck
2007-06-20 20:18                                   ` Jay Belanger
2007-04-17 18:54         ` Jay Belanger
2007-04-18 21:55           ` Christian Schlauer
2007-04-19  2:58             ` Daniel Brockman [this message]
2007-04-22 10:27               ` Christian Schlauer
2007-04-26 16:00                 ` Daniel Brockman
2007-04-19 15:16           ` Drew Adams
2007-04-19 17:05             ` David Kastrup
2007-04-19 17:18               ` Drew Adams
2007-04-19 17:33                 ` David Kastrup
2007-04-16 15:38     ` Richard Stallman
2007-04-17 12:47 ` Randal L. Schwartz
2007-04-18 21:29   ` Christian Schlauer

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