1. Options for Demeter intergration into AspectJ
John Sung

2. Questions
What are the different possible approaches for integrating Demeter into AspectJ?
What are the trade-offs?
performance
time to market
functionality
user’s experience with the tool
“cool factor”

3. Integration Approaches
Optimizing DJ traversals
Traversal with 1 Visitor
Traversal with Multiple Visitors

4. 1. Optimizing DJ Traversals
Partial evaluation of calls to traverse, fetch, gather and asList
Use a preprocessor (DemeterJ?)
Need to be re-evaluated when class graph, traversals and/or visitors change.
Independent from AspectJ

5. 2. Traversal 1 Visitor Implement declare traversal t: from A to B
Traversal code generater in ajc
CPU would be the “visitor”
AspectJ pointcuts and advices would be the advice for the one visitor
Exposes naming convention for traversals
Integrated into AspectJ

6. 3. Traversal Multiple Visitors
Implement declare traversal t(VisitorType): from A to B
Traversal code generator in ajc
Use inheritance to have different visitors for the same traversal
Integrated into AspectJ

7. Approach Comparison 1. Optimizing DJ 2. Traversal 1V 3. Traversal MV
Characteristics
1. Optimizing DJ
localized advice scope
quick implementation
Preprocessor implements some traversal code
another tool to run for the developer
independent from AspectJ
visitors can be specified
2. Traversal 1V
globalized advice scope
CPU as the one visitor
integrated into AspectJ
longer implementation time
exposes inner workings of traversals
3. Traversal MV
visitors can be specified (inheritance)
Similar functionality to 1