Each contexts keep a link to the heap which it is a part
of (when using the native GC), as well as a vector of
special globals that it needs quick access to (e.g. the
`quote' and `quasiquote', etc. symbols. You can use this
to manage multiple completely unrelated VMs in the same
application, and everything will be thread-safe.
The old behavior is still available by editing config.h,
which now includes somewhat better descriptions of all
the settings.
can disable with USE_BIGNUMS=0 - the interactions between this and
USE_FLONUMS are messy, so they will likely be merged into a single
option in the near future (i.e. you either have only fixnums, or a
full range of numeric types).
adding rationals based on this would be easy and is a likely future
feature. adding native support for complex numbers is unlikely.
