Sub Articulo 90.0
I am trying to define an uppercase command which works on characters
defined via \charNN. I have defined an input->output encoding scheme
which maps, via macros
ä -> \glyph@adieresis -> \char228
Ä -> \glyph@Adieresis -> \char196
and then I have set
\uccode228=196 \lccode228=228
\uccode196=196 \lccode196=228
Now I want to be able to uppercase and lowercase token lists.
It is clear to me why \uppercase{ä} and \uppercase{\char228} do not
work: TeX does not expand the arguments of \uppercase and a marco
token is mapped into itself. But I had expected
\edef\test{\noexpand\uppercase\char228} \test
to work, on the assumption that \edef would expand \char228 to it's
"underlying" character token. But it doesn't! Said another way, TeX
doesn't really treat "\char97" the same as "a".
How can I obtain the effect I want?