1. GBBOpen
An interactive OOP tool for Common Lisp
Valeriy Zamarayev
@valeryz

2. BlackBoard Metaphor
● A group of specialists sitting a room with a
large blackboard.
● Work as a team to brainstorm a solution to
a problem.
● Everyone contributes to the blackboard,
when the information on the blackboard
allows to apply their knowledge

3. A bit of History
From 1970s:
● Hearsay II speech recognition
● Interpretation of sonar data for ocean
surveillance projects
More recent:
● Collaborative Network for Atmospheric Sensing
● LiftOff! (Earth observation satellite RADARSAT-1)
● DARPA Urban Challenge (C++ KOGMO RTDB)

4. Alternatives?
● Just use a database to store the current
state with a schema (or, some
schemaless mess) and queries?
– Tight coupling between app code and BB
– Often inefficiency
● Use an custom in-memory representation
developed specifically for the task
● There's a Flexibility vs. Efficiency tradeoff

5. Blackboard Subsystems
● Blackboard
– Storage of objects in hierarchical spaces
– Dimensional retrieval
● Knowledge Sources (KS)
● Control Shell

6. GBBOpen Tools
● Useful CLOS tools
– define-class macro
– MOP tools
● Various libs that should belong elsewhere
● Declared Numerics
● Pseudo Probabilities
● Date/Time
● Datastructures

7. GBBOpen Tools
● Portable Threads
● Scheduled / Periodic Functions
● Sockets
● Double Metaphone
– Etc etc etc.
● Even Modules (like ASDF, why?)

8. GBBOpen CORE
● Links (bidirectional automatically verified)
● Events
● Spaces
● Instance Retrieval

9. Persistence? Streaming?
● Implemented Journaling
● Prevalence-like persistence possible
● Other backends can be implemented (but
not at the moment)

10. Persistence? Streaming?
● Implemented Journaling
● Prevalence-like persistence possible
● Other backends can be implemented (but
not at the moment)