> Guarding against unbounded recursion requires both compiler support and runtime environment support
I feel like this is similar in spirit to saying "guarding against infinite loops requires both ...".
Where resource consumption is concerned, as you pointed out you can track that manually. Presumably you have to do that anyway, since the iterative case will also need to give up and fail the task at some point.
I really don't see where recursion itself introduces an issue here. I guess if you expect to pass through a great many nodes that don't otherwise trigger resource allocation except for the stack frame, and the compiler can't optimize the activation records away, it could be problematic. That's pretty specific though. Is that really the case for a typical parser?
The stack frame also holds local variables. It's not just a return address. If your function requires 3 local variables then each call requires 3 stack slots.
I feel like this is similar in spirit to saying "guarding against infinite loops requires both ...".
Where resource consumption is concerned, as you pointed out you can track that manually. Presumably you have to do that anyway, since the iterative case will also need to give up and fail the task at some point.
I really don't see where recursion itself introduces an issue here. I guess if you expect to pass through a great many nodes that don't otherwise trigger resource allocation except for the stack frame, and the compiler can't optimize the activation records away, it could be problematic. That's pretty specific though. Is that really the case for a typical parser?