= Multiple Changes to CIVL Code =

== Model Changes ==

* add a method to expressions like `SymbolicExpression getConstantValue()` and a corresponding setter, to cache the value of any expression that has a constant value, such as a literal expression
* add new subtype of `Variable`: `CIVLScopeVariable` with method
 * `Scope getScope();`
* add to the CIVL pointer type a method to get the scope variable, implement appropriate constructors and modifications to the factory, etc.

== Semantics Changes ==

* use interfaces for `Executor`, `Evaluator`, etc.
* finish javadocs for all methods
* don't use `Vector`.  Use `LinkedList` if you only need to iterate; use `ArrayList` if you need constant time access
* use `switch` instead of big `if...else if…` sequence (mostly DONE)
* implement pointer subtraction
* construct and set the heap type in the constructor for `Evaluator`, just like the other special types

== Translation ==

Thoughts on processing struct definitions:

* transform the AST to factor out all struct definitions embedded in declarations.  This is really part of "side-effect-removal".