Seminar 
             On
Aspect Oriented Programming

      Presented by Gopal.V



  Yet Another Programming Methodology ?

* Why another ?
* Intentional Programming.
* What's wrong with OOP ?
* Modularity vs. Flexibility.
* Encapsulation vs. Untangling.
* Component based frameworks.



             Aspect Orientation

* Untangling of code
* Crosscutting of concerns
* Aspect independence
* Specific mini-languages
* Aspect weaver
* Object synchronization and management



                What Is an Aspect ?

* Cannot be cleanly encapsulated in a generalized  
  procedure.
* Aspects tend not to be units of the system's 
  functional decomposition, but rather to be 
  properties that affect the performance or semantics 
  of the components in systemic ways. 
* Examples of aspects include memory access 
  patterns and synchronization of concurrent 
  objects.



               Aspect Weaver

* Combines the various aspect fragments.
* Uses a set of rules to automate the process.
* Design reflected in the weaving rules.
* Optimizes the integration code.
* Simplifies debugging and testing.
* Errors about dangling or parallel aspects.



             When Do We Need AOP ?

* In complicated programs to separate code 
  fragments.
* Type information is carried explicitly by the 
  Object.
* A case where the classes are also variables 
  and may change parents or members.
* Where synthetic runtime classes are 
  generated.



          Implementation Examples

* Alisp     ­ Aspect Lisp (initial)
* AspectJ ­ Aspect oriented java 
* Pythius  ­ Aspect oriented python
* Treecc   ­ Aspect oriented compiler tool
* Aspect++ ­ AOP for VC++