[lug] parsing between two lists

[Rob Nagler]

> any particular reason you're using hash refs here, instead of simple
> hashes?

We decided that it was too confusing having hashes and hash refs mixed
in our code.  This way everything is a reference unless it is a scalar
(or an array parameter :-).  It is a little more type safe.  If you
happen to forget to put a backslash on a return value, it can be quite
annoying to debug.  If it is reference to start with, you don't have
this problem.

Rob