vm.nursery and vm->data->nursery are different objects. They get out
of sync when Factor code bumps vm.nursery but leaves vm->data->nursery
unchanged. The emptiness of vm->data->nursery meant that each_object()
never iterated it.
Factor is finally a real C++ project and has a custom assert macro. Assertion failures were still getting caught as exceptions and causing failure loops. Write our own macro that calls factor::abort on failure.
- Move forward declarations of 'struct factor_vm' to one place
- Rename template parameters from T and TYPE to descriptive names. New convention: CamelCase for template parameters
- Change some higher-order functions taking function pointers into templates, and define classes overriding operator(). There's a bit of new boilerplate here but its more consistent than the old mish-mash approaches
- Put GC state into a gc_state struct
- Use exceptions instead of longjmp for non-local control transfer in GC
- In code GC, instead of interleaving code block tracing with copying, add code blocks which need to be revisited to an std::set stored in the gc_state