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Message-ID:  <53675711.5030800@morningstar2.co.uk>
Date:         Mon, 5 May 2014 10:17:05 +0100
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From: Joseph Wright <joseph.wright@MORNINGSTAR2.CO.UK>
Subject: Re: \__dim_strip_bp:n
To: LATEX-L@LISTSERV.UNI-HEIDELBERG.DE
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Status: R

On 05/05/2014 09:55, Frank Mittelbach wrote:
> Am 05.05.2014 01:08, schrieb Heiko Oberdiek:
>> Improved version with higher precision:
>>
>>    \cs_new:Npn \__dim_strip_bp:n #1
>>      {
>>        \__dim_strip_pt:n
>>          {
>>            \__dim_eval:w ( #1 ) * 800 / 803 \__dim_eval_end:
>>          }
>>      }
>>
>> * 800/803 is the integer fraction for 72/72.27
> 
> 
> perhaps I'm completely off the mark, but isn't this introducing a
> restriction on the values that can be entered? (ie generating an
> overflow by doing *800 first)
> 
> frank

    \input expl3-generic %
    \ExplSyntaxOn
    \tl_set:Nx \l_tmpa_tl
      {
        \__dim_strip_bp:n { \c_max_dim }
      }
    \tl_show:N \l_tmpa_tl

gives

    > \l_tmpa_tl=macro:
    ->16322.74998.
    <recently read> }

which I think is OK.
--
Joseph Wright