1. Requirements for better object-oriented design and programming languages
Could be organized better

2. General Requirements Minimize tangling (most important)
tangling of behaviors/issues
structure-shyness
Do type-checking at adaptive level without knowledge of class graph.

3. Requirements Strategic Automata
Support strategic traversal automata
Strategy graph defines 4 kinds of automata: depth-first/breadth-first and class-graph-order/strategy-graph-order
If another traversal is needed, use strategic traversal automaton
traversal automaton is special case: apply to class graph

4. Requirements: Layers of strategy graphs
Allow multiple layers to define strategies. Allows to protect strategies from details of class graphs
Path set is defined by intersection of NDFAs from current strategy to the root

5. Current way of AP G s1 s2 s3 s4 s5

6. Better way of AP G s6 s7 s1 s2 s3 s4 s5
s6, s7 shield s1 through s5 from changes to G

7. Hierarchical development of strategies
s2=[A,B]
s3=[A,C]
s4=[A,B,D]
s5=[A,C,D] G A B
s1= [A,D] bypassing ... G C D s1 s2 s5 s3 s4

8. Requirements Composition of strategies
Support intersection, merge, negation and join of strategies. Allow naming of strategies.
Class graphs and strategy graphs should have similar syntax

9. Example: Requirements Composition of strategies
support operations join and merge
S1 = A=B.B=C.C=.
S2 = A=X.X=Y.Y=C.
S3 = A=Y.Y=X.X=C.
S4 = S1 & (S2 + S3)
join and merge help to avoid long specifications

10. Requirements
To make strategies even more adaptive, we allow regular expressions in class-valued and relation-valued variables.
from Cabinet
bypassing ->*,*poison*,*
to *

11. Requirements {-> Document {[Ss]ection [Pp]aragraph}}
Does not matter: lower case or upper case
Used in the Laurel Query Language: (Abiteboul et al., Journal of Digital Libraries, 1(1), 1997)

12. Requirements Control by strategies
during strategy: during s …
restrict visitor to strategy s
start strategy: start s …
before traversal starts, execute some code
finish strategy: finish s ...

13. Requirements: Backward edges
How should they be supported?
Pattern for derived edges

14. Derived Edge Pattern Meaning of V<-A: For aV of class V
find aA of class A in aG
of class G such that
aA.get_s() returns aV. G
1..* A s
only
1..* V 1
Strategy Graph

15. Derived Edge Pattern V<-A can be used in strategies.
A -> V to-stop
V <- A
gives all neighboring
adjacencies for a given
adjacency. G
1..* A s
only
1..* V 1
Strategy Graph

16. Requirements Visitors
visitors can be composed into a tree: a tree expression binds them together
a visitor can refer to several next visitors which provide it with inputs: next_visitor.x.result()
a visitor has one output

17. Visitors Visitor composition
as part of visitor definition
by independent visitor expressions
Each visitor is parameterized by one strategy which serves as a strategy type. When instantiated with detailed strategy, behavior is defined (like adaptive method).

18. Requirements Object Manipulation
Insertion and deletion should be done in a structure-shy way.
from A to B before B {delete this;}
support for exiting from a traversal

19. Requirements Container classes
Support multiple container classes
Support parameterized syntax in class dictionary: java.util.Stack(S)
Integrate with collection class generator P3?

20. Requirements APPCs
Encapsulate class extensions for groups of collaborating classes
May be parameterized by multiple strategies

21. Requirements APPCs an APPC can ask about results of other APPCs
the composition structure of APPCs is a dag

22. Requirements Physical Organization
separate files for class dictionaries(*.cd), visitors (*.vis), adjusters (*.adj) and behaviors (*.beh), strategies (*.str).

23. Requirements Coordination: Formally verify small cases
Coordinator defines finite state machine for small parameters.
Use model checking techniques.
Model checking: temporal logic versus pi-calculus. Use temporal logic.