Question

I have a ruby service that keeps running forever and I wonder whats the cost of recursivity. When I ctrl-c the service after some time, I get the following error printed:

^Cff.rb:169:in `sleep': Interrupt
    from ff.rb:169:in `fetch'
    from ff.rb:170:in `fetch'
    from ff.rb:187:in `fetch'
    from ff.rb:180:in `fetch'
    from ff.rb:170:in `fetch'
    from ff.rb:187:in `fetch'
    from ff.rb:177:in `fetch'
    from ff.rb:170:in `fetch'
 .... and continue for each recursive call

This makes me wonder if this has a memory cost or if it eventually will fail? Is it bad to use recursive in Ruby like this? Would another solution be better? Ty.

Answer 1

AFIAK, Ruby never turns tail call recursion into loops. If you keep calling a function recursively, eventually you’ll run out of memory.