ProgramNodeEnumerator
 
 
ProgramNodeEnumerator is a visitor for the Smalltalk-80 compiler.
Smalltalk compiler parse tree hierachy rarely changes.
There are lots of potential programs that need to traverse trees:
- • consistency checkers
 - • program transformation
 - • metrics
 
It makes sense to keep these applications out of the parse tree.
Easy to make minor variations on tree walking applications.