String -> register conversion

String -> register conversion

[Hans Hagen]

[bounced mail, use address know to list]

>Hi,
>
>It have a probably very stupid question to ask; but so far doing math in 
>TeX did
>not come in my way.
>
>How can I make the following work in Tex? :
>
>\def\mac{10}
>\newcount\cnt
>\cnt=\mac
>\the\mac
>\bye
>
>The idea is simple. I want TeX to expand \mac and make an assignment to 
>register
>\cnt. I tried \expandafter\cnt=\mac, but it doesn't work. Perhaps because 
>of the
>= after \cnt.

first of all, \the\mac is wrong, since \mac is no register, so that one 
should be \the\cnt

but then, again you get not what you want, because tex keeps on reading 
until no numbers are found, so you need to stop reading by saying 
\cnt=\mac\relax (or \cnt\mac\space)

if you want a neutral way to get a number, use \number\cnt or \number\mac 
since \number is less strict in what it expects

Hans

PS. Of course a google search does not work, since mac will always lead you 
to big macs i suppose -)
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Re: String -> register conversion

[Slawek Zak]

On Wed, 06 Feb 2002, Hans Hagen verbalised:
> [bounced mail, use address know to list]

Fixed, thanks.

>>How can I make the following work in Tex? :
>>
>>\def\mac{10}
>>\newcount\cnt
>>\cnt=\mac
>>\the\mac
>>\bye
>>
>> The idea is simple. I want TeX to expand \mac and make an assignment to
>> register \cnt. I tried \expandafter\cnt=\mac, but it doesn't work. Perhaps
>> because of the = after \cnt.
> 
> first of all, \the\mac is wrong, since \mac is no register, so that one should
> be \the\cnt

Sure. My fault. I meant \the\cnt of course.

> but then, again you get not what you want, because tex keeps on reading until
> no numbers are found, so you need to stop reading by saying \cnt=\mac\relax
> (or \cnt\mac\space)

Ouch. \relax, I should've thought of it. Thanks.

> if you want a neutral way to get a number, use \number\cnt or \number\mac
> since \number is less strict in what it expects

Yep. That reminds me to put The TeXbook lecture on my to-read list again ;)

> PS. Of course a google search does not work, since mac will always lead you to
> big macs i suppose -)

Apple would come up as the first search result on Google, actually ;)

/S
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* Suavek Zak / PGP: finger://zaks@prioris.mini.pw.edu.pl