Once we've changed the builtins to the correct type we can create a function that registers all of our builtins into an environment.
-For each builtin we want to create a function lval and symbol lval with the given name. We then register these with the environment using lenv_put. The environment always takes or returns copies of a values, so we need to remember to delete these two lval after registration as we won't need them any more.
For each builtin we want to create a function lval and symbol lval with the given name. We then register these with the environment using lenv_put. The environment always takes or returns copies of a value, so we need to remember to delete these two lval after registration as we won't need them any more.
If we split this task into two functions we can neatly register all of our builtins with some environment.