GNU bug report logs - #921
In CVS Emacs, calc-eval gives multiplication higher precidence than division

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Package: emacs;

Reported by: jay.p.belanger <at> gmail.com

Date: Sun, 7 Sep 2008 20:45:03 UTC

Severity: normal

Merged with 914, 915, 918, 920, 923, 924, 928, 929, 930, 932, 933, 934, 937, 941, 944

Done: Chong Yidong <cyd <at> stupidchicken.com>

Bug is archived. No further changes may be made.

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Message #5 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Jay Belanger <jay.p.belanger <at> gmail.com>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: Francis Litterio <flitterio <at> gmail.com>, bug-gnu-emacs <at> gnu.org,
        emacs-devel <at> gnu.org
Subject: Re: In CVS Emacs, calc-eval gives multiplication higher precidence than division
Date: Sun, 07 Sep 2008 15:35:37 -0500

>> That's not a bug.  While many systems give division a higher precendence
>> than multiplication, that isn't a universal rule.
>
> Actually, I don't know of any system that gives higher precedence to
> division.

According to Wikipedia:
  An expression like 1/2x is interpreted as 1/(2x) by TI-82, but as
  (1/2)x by TI-83. While the first interpretation may be expected by
  some users, only the latter is in agreement with the standard rules
  stated above. 

> The general rule that (AFAIK) all programming languages
> follow (other than those that don't use infix-with-precedence, such as
> Lisp and Smalltalk) is that * and / have the same precedence (and are
> left associative).

That behavior is available, but you have to ask for it by setting
`calc-multiplication-has-precedence' to nil.
This bug report was last modified 16 years and 256 days ago.

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