scala self

scala self explaination

http://www.scala-lang.org/old/node/8194.html
http://stackoverflow.com/questions/4017357/difference-between-this-and-self-in-self-type-annotations

3 forms:
  trait A {self: B =>..}
  trait A {self =>..}
  trait A {this: B =>..}
  
  trait A {self: B =>..} is the most useful one. used primary for mixins. 
    'A' implements a small groups of very specific operations for very generic type. 'B' could be potentially implements another a small group.
    'A' always used in mixed with 'B' (or its sub types) to form a greater sets of operations

  trait A {self =>..}
    useful in nested class definitions
    
  trait A {this: B =>..}
    same as #1 without any alias