The Inverse World of the FOREST Object Web Duncan Cragg Part 1 - Overview

1. The Inverse World of the FOREST Object Web Duncan Cragg Part 1 - Overview

2. FOREST is an architecture that resonates with stuff like this: • Clojure Agents / Scala & Erlang Actors • Dataflow / Reactive Programming • Declarative / Functional Programming • Concurrency, Map-Reduce • NoSQL, Eventual Consistency • REST, Resource-Oriented Architectures

3. FOREST describes a new kind of Object...

4. FOREST Objects are Happy Objects

5. They are happy because no-one tells them what to do

6. Normal Objects are covered with methods

7. ..which other Objects can call whenever they want

8. ..as long as they happen to know the particular interface ?

9. Normal Objects keep their state hidden under wraps

10. FOREST Objects show their state to everyone

11. and that state is in a standard form that everyone understands

12. FOREST Objects are internally-animated

13. All the methods are on the inside

14. FOREST Objects are Inverse Objects

15. FOREST Objects are Inverse Objects Tell Don't Ask Ask Don't Tell

16. Another reason FOREST Objects are so happy is that they have lots of friends

17. Which are kept through links or URLs in their public state

18. FOREST Objects link up into a single Web - "hyperdata" - a semantic Web!

19. A Global Object Web

20. FOREST Objects interact with their friends

21. An Object affects another through its public state

22. An Object affects another through its public state "An object's state evolves

23. An Object affects another through its public state "An object's state evolves as a function of

24. An Object affects another through its public state "An object's state evolves as a function of its own state and

25. An Object affects another through its public state "An object's state evolves as a function of its own state and the state of other objects, local and remote,

26. An Object affects another through its public state "An object's state evolves as a function of its own state and the state of other objects, local and remote, that it observes directly or indirectly through links"

27. A Global Interacting Object Web

28. Now for a simple example - an Object whose state is a function of a couple of sub-Objects .. it joins their text up

29. joiner Hello Hello World World

30. joiner Greetings Hello World World

31. joiner Greetings Greetings World World

32. Let's see that again... it's your first FOREST program!

33. joiner Hello Hello World World

34. joiner Greetings Hello World World

35. joiner Greetings Greetings World World

36. "An object's state evolves as a function of its own state and the state of other objects, local and remote, that it observes directly or indirectly through links"

37. An Object's state will be much more complex than that example: it's an arbitrary JSON structure

38. State update notification is propagated to observing Objects asynchronously - through queues

39. An Object can read a linked Object's state at any time; FOREST supports eager and lazy modes

40. So FOREST is easy to program: look at current and linked states, then set new state accordingly

41. You can still use traditional Objects for this animation on the inside

42. FOREST Objects can still be animated in any language Javascript Ruby Java Erlang C# F# Python Clojure Haskell Scala C

43. But more naturally, FOREST Objects can be programmed Declaratively

44. Which is a lot like... Rules Programming HTML Spreadsheet Formulae CSS

45. Another reason FOREST Objects are so happy, is that they're free!

46. Not just free of being told what to do by other objects, but free of a bounding application

47. FOREST is a Global Interacting Object Web

48. Traditional Objects can only work in an application context Application Application

49. And you have to do all the co-ordination, threads and remote calls yourself, Imperatively

50. A FOREST Object only has itself to co-ordinate .. it doesn't need an application