Modifed grammar files (grammar.y and lex.l) to deal correctly with variable expressions. Added support for procedure definitions and the 'protected' keyword for member variable definitions in user-defined types.
User functions and user procedures are now fully supported, including compiler checks of user-defined function code. Variables and function calls have been changed in the flex-bison layer to be fully generic. Some minor bug fixes in the parser code.
Bug fixes and complementary work on containers to support abstract element vectors and missing (NA) objects, plus some work on the printValue and printStructure functions.
Fixed DAG cloning problems in ElementLookupNode. Fixed memory leak in Variable destructor introduced with the DEBUG_MEMORY define. Added support for NA elements of vectors, and model vectors of abstract elements. Fixed several minor problems with the container implementation.
Fixed an NA value issue with Simplex objects.
Added examples file advnaced.Rev for advanced language features
Merged with development branch
Fixed NA value implementation for model vectors of abstract Rev objects.
Fixed some minor NA printing issues. Fixed an NA printing bug introduced by the merge.
Fixed a minor compile problem.
Minor modifications to basics.Rev and advanced.Rev examples files