... let me count the ways.
I can test it with
And there I stop, both in my knowledge and my poetic ability (though some might argue that the latter never started).
Background: I'm still trying to get my head around the statement of what
\noexpandtemporarily sets the next token to
The purpose of setting it to
\relax seems to be that since
\relax is not expandable, the next token does not get expanded the next time that TeX tries to expand it. But it does get expanded the time after that, so that seems to be the meaning of "temporarily".
But is the fact that it is temporarily set to
\relax detectable? To test this, I want to examine what TeX thinks
\noexpand\foo is, but that "temporarily" keeps getting in the way: it's all a bit quantum since the act of observing a
\noexpand\foo seems to change it in some way.
Anyway, so I want to build a test suite to see if the value of
\noexpand\foo is detectable in a significant way and for that, I need to know all the ways that I can get at its value, such as conditionals and
\show. And that's my question.
Question: What ways are there of examining a macro or active token in TeX which reveal something about what it points/expands to?