AspectOriented Programming: Fad or the Future

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Aspect-Oriented ProgrammingFad or the Future

• Karl Lieberherr
• Northeastern University
• UBS AG

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AOP Factoring out similarities that cut across
abstractions
C1
Adapters
Specific behavior 1
s1
C2
P1
C3
C6
P2
s2
Specific behavior 2 similar to behavior 1
Generic behavior Collaborations
C7
C8
AOP solution less redundancy, requires tool
support
C9
Traditional solution redundancy
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The goal Tangling control

• Tangling cannot be eliminated, it can only be
  reduced and localized.
• The goal is to encapsulate program enhancements
  and minimize dependencies between them (loose
  coupling).

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definition
result
deployment
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Collaborations (APPC)
minimal assumptions on application structure
Participant Graph
P1
P3
P2

required interfaces
Behavior Definition
P
P1
add new functionality enhance the required
provided everything declared public

...
written to the PG similar to an OO
program is written to a concrete class graph

P3
...
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Deployment/Composition of Collaborations

• Specified by adapters separately from
  collaborations
• Adapters specify crosscutting using
• regular-expressions to express sets of method
  names and class names and interface names
• code where simple method name mapping is not
  enough
• graphs and regular expression-like constructs for
  mapping graphs

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Design issues

• What goes into collaborations and what goes into
  adapters?
• Depends on reuse of collaboration C.
• Consider n reuses of the same collaboration
  A1(C), A2(C), ,An(C)
• The goal is to put enough information into
  collaboration C so that in the adapters contain
  minimal code duplication.

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Rough correspondences
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Fad or Future

• Future!
• Many issues to be resolved
• Correctness
• aspect
• composition of aspects
• conflicts between aspects
• Trying to unify the existing approaches taxonomy
  of the design space