Re: [ConTeXt] Math fonts: cal etc.

[Hans Hagen <pragma@wxs.nl>]

Ed L. Cashin wrote:
> 
> Hans Hagen <pragma@wxs.nl> writes:
> 
> [...]
> > \def\fraktur    #1{\ifmmode\hbox\fi{\frak#1}}
> > \def\gothic     #1{\ifmmode\hbox\fi{\goth#1}}
> > \def\caligraphic#1{\ifmmode\hbox\fi{\cal #1}}
> >
> > will do what you want. I can add those if needed/wanted/agreed upon.
> 
> I have only used "if" a little, but is the "fi" really supposed to go
> *before* the hbox like that?  If it is, then why is it there instead
> of after the hbox as I'd expect?

imagine not being in hmode: 

\ifmmode -> false -> fast read until \fi -> {\frak#1}

but in mmode: 

\ifmmode -> true -> start reading h specs until { expanding everything
-> meet \fi which ends the \if so ok -> see { -> \hbox{\frak#1} 

alternatively you can say: 

\ifmmode\expandafter\hbox\fi{\frak#1}

or when in mmode: 

expandtoken after \hbox being \fi -> so end the \if -> take the \hbox ->
etc etc 

It had to do with the fact that \fi is a signal, not expending to
anything to be typeset or read as keyword. In principle such a \fi can
even go after the { when suitable! 

If yoy want to see a real dirty one (there are some more), take a look
at \doifnumberelse. 

Hans 

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                                          Hans Hagen | PRAGMA ADE
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