From: Vincent Lefevre <vincent@vinc17.net>
To: zsh-workers@zsh.org
Subject: Re: Math expression evaluation error?
Date: Mon, 12 Jan 2015 10:17:37 +0100 [thread overview]
Message-ID: <20150112091737.GB27773@xvii.vinc17.org> (raw)
In-Reply-To: <54B205B8.4080208@eastlink.ca>
On 2015-01-10 21:10:16 -0800, Ray Andrews wrote:
> Sure. That's the best argument for leaving it alone and of course it is
> perfectly sound. I'd go the other way, liking friendliness more, but
> I respect your decision. And I could be quite wrong about 1/2 + 1/2 = 0,
> strange as it looks to me, rounding down could be vital to some code
> somewhere.
It's only a notation problem. Unfortunately / was chosen (historically,
not by zsh) as the symbol for integer division. The shell expression
1/2 + 1/2 just means:
integer_div(1,2) + integer_div(1,2)
where integer_div is the integer division function, which gives 0.
This is perfectly correct math.
--
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
next prev parent reply other threads:[~2015-01-12 9:17 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-09 19:46 jdh
2015-01-09 20:15 ` Peter Stephenson
2015-01-09 21:40 ` jdh
2015-01-09 22:19 ` Ray Andrews
2015-01-09 23:06 ` Lawrence Velázquez
2015-01-09 23:52 ` Ray Andrews
2015-01-10 0:25 ` Bart Schaefer
2015-01-10 7:27 ` Ray Andrews
2015-01-10 16:53 ` Bart Schaefer
2015-01-10 18:48 ` Ray Andrews
2015-01-10 19:14 ` Bart Schaefer
2015-01-10 22:21 ` Ray Andrews
2015-01-11 1:51 ` Bart Schaefer
2015-01-11 5:10 ` Ray Andrews
2015-01-12 9:17 ` Vincent Lefevre [this message]
2015-01-12 16:18 ` ZyX
2015-01-13 16:00 ` Vincent Lefevre
2015-01-13 23:03 ` ZyX
2015-01-14 14:47 ` Vincent Lefevre
2015-01-14 21:37 ` ZyX
2015-01-15 13:34 ` Vincent Lefevre
2015-01-15 13:41 ` Vincent Lefevre
2015-01-15 18:32 ` ZyX
2015-01-15 21:57 ` Bart Schaefer
2015-01-09 22:40 ` Peter Stephenson
2015-01-12 10:55 ` Peter Stephenson
2015-01-14 15:02 ` Vincent Lefevre
2015-01-14 15:38 ` Peter Stephenson
2015-01-15 14:58 ` Peter Stephenson
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