Encapsulating and Exploiting Change with Changeboxes. SCG Bern. ESUG 2007, Lugano

1. Encapsulating and Exploiting Change with
Changeboxes
Marcus Denker
Tudor Gîrba
Adrian Lienhard
Lukas Renggli
Oscar Nierstrasz
Pascal Zumkehr

3. Marcus Denker
Tudor Gîrba
Adrian Lienhard
Lukas Renggli
Oscar Nierstrasz
Pascal Zumkehr

4. Change happens.

7. “Depend in the direction of stability.”

8. Version i Version i+1
RemoveChange Add
A
do
something
B
foo
...
A
do
something
else
anotherDo
...
B
foo
...
C
bar
...

9. “Commit often.”

10. Update

11. Update Change

12. Update Change Commit

13. Update ? Commit

16. We put the change in a box

17. 1

18. 1 2
Change
Specification
Changeboxes encapsulate changes.

19. 1 2 3
Change
Specification
1*
spec
ChangeBox
Changeboxes are immutable.

20. 1 2 3
4
Change
Specification
1*
spec
ChangeBox

21. 1 2 3 5
4
Change
Specification
1*
*
spec
ancestor
ChangeBox
Changeboxes are applied on other Changeboxes.

22. 1 2 3 5
4
Change
Specification
1*
*
spec
ancestor
Merge
Strategy
1
merger
ChangeBox
Changeboxes are applied on other Changeboxes.

23. 1 2 3 5
4
Element
Change
Specification
*1 1*
*
target spec
ancestor
Merge
Strategy
1
merger
ChangeBox
Changeboxes define the scope for dynamic execution.

24. Element
Change
Specification
*1 1*
*
target spec
ancestor
Merge
Strategy
1
merger
ChangeBox
Class
Element
Method
Element
Definition
Specification
Rename
Specification
...

25. A
B
B x
^1
B y
^2
B z
^3
B w
^4
A x
^10
B x B z
Method lookup is similar to Classboxes.

26. A
B
x -> a MethodElement
MethodDict
x -> a MethodElement
y -> a MethodElement
z -> a MethodElement
w -> a MethodElement
MethodDict
B x
^1
B y
^2
B z
^3
B w
^4
A x
^10
B x B z
Method lookup is similar to Classboxes.

27. A
B
x -> a MethodElement
MethodDict
x -> a MethodElement
y -> a MethodElement
z -> a MethodElement
w -> a MethodElement
MethodDict
B x
^1
B y
^2
B z
^3
B w
^4
A x
^10
B x B z
Method lookup is similar to Classboxes.
B new x ?

28. Classes are looked up in a similar way.

29. Merge is supported via a MergeStrategy.

30. Changeboxes encapsulate changes.
Changeboxes are immutable.
Changeboxes are applied on other Changeboxes.
Changeboxes define a scope for dynamic execution.

31. Encapsulate and exploit change in Changeboxes