Globals/Bindings: Continuations with Mini-Lisp #452
Description
Can be done if we add two primitives for READ and WRITE, but more importantly, by modifying the a-list as we do in the JS and Chic implementations.
Yet another option is to implement the eval using what is known as continuation, in which recursion replaces sequential execution.
The book makes a little lie on relying on the REPL to define functions.
Once this is agreed, we can still decide whether an aborted execution undoes the sets done within it. But, since the SET operation is a global one, it makes no sense to undo it.