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From: jdh <dhenman@gmail.com>
To: zsh-workers@zsh.org
Subject: Math expression evaluation error?
Date: Fri, 09 Jan 2015 11:46:44 -0800	[thread overview]
Message-ID: <54B03024.1030309@gmail.com> (raw)

I believe I read that math expression evaluation will convert all
calculations in an expression if "any" value in that expression is a
real value.

That is not true if the word "any" is true or a bug has crawled into the
numeric expression evaluator.  Or I read wrong..

Example on my system, zsh 5.0.7 (i686-pc-linux-gnu), I get the following
results for the shown example:

$ echo $(( 6+3/8. + 10 + 5/8. )) $(( 6+3/8 + 10 + 5/8. ))
                               17. 16.625

In the above case only the second term which contains a real number is
evaluated as real , the previous term is taken as integer and decimal
values are truncated (non-existent.   This same behavior is demonstrated
in zcalc.  Probably uses the same logic.

Though I understand why this happens (or think I do).  It could cause
someone a major mistake if they are unaware of this and rely on the outcome.

Regards

  Darel


             reply	other threads:[~2015-01-09 19:47 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-09 19:46 jdh [this message]
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
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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