I think I might use dynamic scoping if it really is easier to implement, and the analyzer’s ‘world’ object already has a central variable table. All I have to do is, instead of declaring the identifiers in key:value pairs, it will be key:list pairs. Each list is a stack of values for that variable. The position of each element in the list corresponds with the variable’s dynamic scope.
That might not be what Wikipedia is talking about here, but I’ll try it anyhow.
Dynamic scoping is fairly easy to implement. To find an identifier’s value, the program could traverse the runtime stack, checking each activation record (each function’s stack frame) for a value for the identifier. In practice, this is made more efficient via the use of an association list, which is a stack of name/value pairs. Pairs are pushed onto this stack whenever declarations are made, and popped whenever variables go out of scope. Shallow binding is an alternative strategy that is considerably faster, making use of a central reference table, which associates each name with its own stack of meanings. This avoids a linear search during run-time to find a particular name, but care should be taken to properly maintain this table. Note that both of these strategies assume a last-in-first-out (LIFO) ordering to bindings for any one variable; in practice all bindings are so ordered.
An even simpler implementation is the representation of dynamic variables with simple global variables. The local binding is performed by saving the original value in an anonymous location on the stack that is invisible to the program. When that binding scope terminates, the original value is restored from this location. In fact, dynamic scope originated in this manner. Early implementations of Lisp used this obvious strategy for implementing local variables, and the practice survives in some dialects which are still in use, such as GNU Emacs Lisp. Lexical scope was introduced into Lisp later. This is equivalent to the above shallow binding scheme, except that the central reference table is simply the global variable binding environment, in which the current meaning of the variable is its global value. Maintaining global variables isn’t complex. For instance, a symbol object can have a dedicated slot for its global value.