Mojca Miklavec wrote:
>
>
> Seems like understanding \expandafter would solve 90% of my problems.
> I tried to understand that part in TeX book, but it's so cryptic (too
> short) ... I understand the concept, but I'm not able to write the
> code for it yet :(
The trick to \expandafter is that you (normally) write it backwards
until reaching a moment in time where TeX is not scanning an argument.
Say you have a macro that contains some stuff in it to be typeset by
\type:
\def\mystuff{Some literal stuff}
Then you begin with
\type{\mystuff}
but that obviously doesn't work, you want the final input to look like
\type{Some literal stuff}
Since \expandafter expands the token that follows the after next token
-- whatever the next token is -- you have to insert it backwards across
the opening brace of the argument, like so:
\type\expandafter{\mystuff}
But this wouldn't work, yet: you are still in the middle of an
expression (the \type expects an argument, and it gets \expandafter
as it stands).
Luckily, \expandafter *itself* is an expandable command, so you
jump back once more and insert another one:
\expandafter\type\expandafter{\mystuff}
Now you are on 'neutral ground', and can stop backtracking.
Easy, once you get the hang of it.
Taco
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