[Kjetil Torgrim Homme]:
> the slightly nasty consequence of this is that the string
> specifying the variable itself can contain variable
> references. it is impossible to know at compile time whether
> the resulting variable name is valid.
Suppress/disallow variable expansion in the first arg of SET?
suppress makes the parser quite hairy unless we add a single quoted
string or similar. disallow could work, but we still need to handle
the same syntax errors. we only remove the ability to do indirect
setting of variables. this isn't a very useful ability, since there
is no corresponding indirect lookup of variables, but I'm sure it can
be exploited somehow...