How to implement a garbage collector?

Question

Could anyone point me to a good source on how to implement garbage collection? I am making a lisp-like interpreted language. It currently uses reference counting, but of course

Answer 1

I'm doing similar work for my postscript interpreter. more info via my question. I agree with Delnan's comment that a simple mark-sweep algorithm is a good place to start. You'll need functions to set-mark, check-mark, clear-mark, and iterators for all your containers. One easy optimization is to clear-mark whenever allocating a new object, and clear-mark during the sweep; otherwise you'll need an entire pass to clear marks before you start setting them.