[texhax] controlling expansion

[Neal H. Walfield]

These are valid concerns in the general case.  In my particular case,
however, I really am interested in the empty string, i.e., ''.

Thanks,

Neal

At Thu, 28 Feb 2013 15:15:02 +0000,
Lars Madsen wrote:
> 
> And what exactly would you consider empty, is \dosomething{ } empty or not?
> 
> /Lars Madsen
> Institut for Matematik / Department of Mathematics
> Aarhus Universitet / Aarhus University
> Mere info: http://au.dk/daleif@imf / More information: http://au.dk/en/daleif@imf
> 
> 
> ________________________________________
> From: texhax [texhax-bounces at tug.org] on behalf of Michael Doob [mdoob at cc.umanitoba.ca]
> Sent: 28 February 2013 16:02
> To: texhax at tug.org
> Subject: Re: [texhax] controlling expansion
> 
> On 13-02-28 08:51 AM, Neal H. Walfield wrote:
> > I spent some time reading and found a good solution for determining
> > whether an argument is empty in David Solomon's Advanced TeXbook:
> >
> >    \ifx\empty#1\empty empty \else not empty\fi
> >
> > Nice trick!  TeX requires a lot of lateral thinking.
> 
> Cute, but what about \empty{\empty}? :-)
> 
> Cheers,
> Michael
> 
> 
> --
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> Michael Doob                    Telephone: (204) 474-9796
> Department of Mathematics       Fax: (204) 474-7606
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