Hyper/J

1
Hyper/J

• George Fairbanks CMU Fall 2004
• Objects and Aspects, Jonathan Aldrich
• 12 November 2004

2
Harumph!
Too cold!
Too hot!
Everything stinks!
3
Outline

• History
• Subjects
• Multi-Dimensional Separation of Concerns
• Hyper/J
• Artifact structure
• Hyperspaces
• Concerns
• Hypermodules
• Merging
• Experience
• Discussion

4
History Subjects

• Objects are good because of polymorphism and
  encapsulation
• In a large team, different programmers want to
  extend the object to add their functionality
• How is a poor programmer supposed to anticipate
  all those features?

5
History MDSoC

• MDSoC Multi-Dimensional Separation of Concerns
• Meta, very meta
• Hyperslice
• A set of modules where all code is for a given
  concern
• Declaratively complete not a simple partition
• Tyranny of the dominant decomposition
• The primary structure of a system
• Tangling
• One method has code for many concerns
• Scattering
• Code for one concern in many methods

6
Tooling CME

• CME Concern Manipulation Environment
• I would have a live demo of CME here but all I
  can seem to do is hang it. It is version 0.1.2.

7
Simulating Hyperslices

• We simulate them using Open Classes a class
  definition may be spread over multiple files.
  Cannot define composition operators but we dont
  need them now. Tools we use AspectJ, DemeterJ.
• We use adaptive hyperslices Those are
  hyperslices that are parameterized by a traversal
  (a class graph and a traversal strategy) and
  visitors. Reduces coupling. Improves reusability.