Call/cc is pretty simple to implement depending on how you chose to represent your scheme code. Using CPS call/cc is trivial. Hygienic macros are however never

Call/cc is pretty simple to implement depending on how you chose to represent your scheme code. Using CPS call/cc is trivial. Hygienic macros are however never trivial. It is so many kinds of tricky, and together with the nice debugability of macros you find yourself in a nice place.