[texhax] Any crazy math formulas for testing a TeX language interpreter

[Douglas McKenna]

Joseph Wright wrote -

> In any case, some form of expandable comparison that ignores catcodes is
> very useful, and it's essential to use expl3 (we found some years ago
> that this was the one post-e-TeX primitive that was vital in all cases,
> though as David notes once you get to dealing with Unicode then some
> ability to generate tokens across the full range is also needed).


So … something like a three-way switch, e.g.,

\ifstrcmp <char token list> <char token list>
     <case 0 for less than> \or
     <case 1 for equal> \or
     <case 2 for greater than>
     \fi

?

Or a two-way explicit comparison of some kind, e.g., 

\ifstrcmp { <char token list> } < = > { <char token list> }
		TRUE
	\else
		FALSE
	\fi

?