J%ORG KNAPPEN writes:

 > Long time ago, I wrote my own inputenc files making *all* high characters
 > text character. The definition files (latin1jk.def, latin2jk.def,
 > and latin3jk.def) are available from CTAN
 > (latex/contrib/supported/jknappen).
 >

something like this yes (perhaps even exactly this)

 > If the standard inputenc files are changed, I strongly plea for "dual use"
 > characters. The standard ASCII characters with a few exceptions can be used
 > in text and math as well. A user expects the high character not to be
 > different
 > in this respect.

depends on what dual means. if you mean that you want the result of a key
mapping (eg \"a) be available text or math then

i'm not. i strongly plea for math only accepts the small set of real
ascii, ie

 0-9  a-z A-Z  !"/()=?`'+*<>|,;.:-
 plus commands

by default (repeat: default).

the set of exceptions is a) not well-defined an b) potentially unlimited and
thus even more difficult to explain than anything else.

because what you are really have to do then is to make all font encoding
specific commands available in math and that doesn't work, a lot have to
equivalent there.

 > However, the whole setup using active characters makes such kind of change
 > rather difficult.

it is not so much that but the question what \c{c} should mean in math, should
it map to \mbox{\c{c}}? probably not; should \"a map to \ddot\a ?
perhaps. what about \`\^{a} as supported by T5 Vietnamese?

right now there are roughly 900+ font-encoding-specific commands, i want to
keep those text (only).

so i don't think "math" should be regarded as another "fontencoding" though
that would be possible in theory.

instead i would think something like \DeclareInputTextAndMath should be
offered for those languages/keyboards where a dual nature for input "keys"
really makes sense, greek and cyrillic comes to mind.

but i would consider this a dual mapping from input "key" to either a text
command (if in text) or a math command if in math, eg

\DeclareInputTextAndMath{<somenumber>}{\textalpha}{\alpha}

you may have meant that as well, have you?


i still feel that for something like latin1 this doesn't make much and i would
prefer to see only \DeclareInputText there but ...

frank