Exercises in Programming Style

Chapter 15

Bulletin Board

15.1 Constraints

• Larger problem is decomposed into entities using some form of abstraction (objects, modules or similar).
• The entities are never called on directly for actions.
• Existence of an infrastructure for publishing and subscribing to events, aka the bulletin board.
• Entities post event subscriptions (aka "wanted") to the bulletin board and publish events (aka "offered") to the bulletin board. The bulletin board infrastructure does all the event management and distribution.

15.2 A Program in this Style

  1 #!/usr/bin/env python
  2 import sys, re, operator, string
  3
  4 #
  5 # The event management substrate
  6 #