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Message-ID:  <22d44ac9-e01e-ff4d-dbe5-fcca7aa9a4b3@gmail.com>
Date:         Fri, 2 Dec 2016 22:47:35 -0500
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From: Bruno Le Floch <blflatex@GMAIL.COM>
Subject: Re: Rounding quirk in l3fp
To: LATEX-L@LISTSERV.UNI-HEIDELBERG.DE
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Status: R

On 12/02/2016 09:47 AM, Bruno Le Floch wrote:
> On 12/02/2016 04:07 AM, Andrew Parsloe wrote:
>> I stumbled on the following quirk recently:
>>
>> \tl_clear:N \l_tmpa_tl
>> \fp_eval:n { round( \l_tmpa_tl, 4) }
>>
>> gives 4 as the answer (or whatever the rounding value is). Usually, in
>> the situation where this arose, \l_tmpa_tl is a string of digits
>> possibly including a decimal point. In this instance it was empty. Okay,
>> I can check for that, but I wonder if l3fp should do so, and either give
>> an error, as
>>
>> \fp_set:Nn \l_tmpa_fp { \l_tmpa_tl }
>>
>> does when the token list is empty, or give a conventional 0 as answer?
>>
>> Andrew
> 
> Thanks, this is a bug.  A better behavior would be to throw an error and
> give nan.
> 
> This is due to my recent commit adding random number support: to allow
> for rand() I did the easiest thing which was to allow and ignore empty
> arguments.
> 
> I'll fix it some time this month.
> 
> Best regards,
> 
> Bruno
> 

Fixed in commit r6772.

Thanks again,

Bruno