From: Bart Schaefer <schaefer@brasslantern.com>
To: Daniel Shahaf <d.s@daniel.shahaf.name>
Cc: Nikolaus Thiel <klt@fsfe.org>,
"zsh-workers@zsh.org" <zsh-workers@zsh.org>
Subject: Re: zmathfunc: min, max, sum throw error if result equals 0
Date: Sun, 7 Mar 2021 13:39:52 -0800 [thread overview]
Message-ID: <CAH+w=7bPz5u9-mQPbmPmbo=8Cz8em7JmbSn-sp8eZzuvFW3mnQ@mail.gmail.com> (raw)
In-Reply-To: <20210307171712.GA9936@tarpaulin.shahaf.local2>
On Sun, Mar 7, 2021 at 9:17 AM Daniel Shahaf <d.s@daniel.shahaf.name> wrote:
>
> Nikolaus Thiel wrote on Sun, Mar 07, 2021 at 17:37:09 +0100:
> >
> > When the result of min, max or sum equals 0, the functions throw an error.
I would not equate "return nozero" with "throw an error", FWIW.
> Ouch. Patch series attached.
I think your regression tests cover this, but use of "true" avoids
changing the result in "functions -M" context, correct?
Is it worth testing invalid cases? Such as uses outside math context
where the arguments are not syntax checked?
As long as we're on the subject:
zsh_math_func_min() {
local result=$1
shift
local arg
for arg ; do
(( $arg < result )) && result=$arg
done
(( result ))
true # Careful here: `return 0` evaluates an arithmetic expression
}
Because of the way math context works, if any of $@ is a string that
can be interpreted as a math expression, the above will evaluate it at
least twice (and up to $# times in the case of $1). This could have
side-effects.
zsh_math_func_min() {
local result=$(( $1 ))
shift
local arg n
for arg ; do
(( n = arg )) # evaluate arg exactly once
(( n < result && (result = n) ))
done
(( result ))
true # Careful here: `return 0` evaluates an arithmetic expression
}
next prev parent reply other threads:[~2021-03-07 21:40 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-07 16:37 Nikolaus Thiel
2021-03-07 17:17 ` Daniel Shahaf
2021-03-07 21:39 ` Bart Schaefer [this message]
2021-03-07 21:56 ` Daniel Shahaf
2021-03-08 2:25 ` Bart Schaefer
2021-04-16 18:26 ` Daniel Shahaf
2021-04-16 18:47 ` Bart Schaefer
2021-04-16 19:50 ` Daniel Shahaf
2021-04-16 20:05 ` Bart Schaefer
2021-04-16 20:08 ` Daniel Shahaf
2021-04-16 18:21 ` Daniel Shahaf
2021-05-16 14:54 ` Lawrence Velázquez
2021-05-18 2:02 ` Daniel Shahaf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAH+w=7bPz5u9-mQPbmPmbo=8Cz8em7JmbSn-sp8eZzuvFW3mnQ@mail.gmail.com' \
--to=schaefer@brasslantern.com \
--cc=d.s@daniel.shahaf.name \
--cc=klt@fsfe.org \
--cc=zsh-workers@zsh.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/zsh/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).