Held: ,

Back to Outline 19 - UML. On to Outline 21 - Good Design, Revisited.

Summary

We consider the use of design patterns in software design.

Related Pages

Overview

• Design patterns.
• Reading reflections.
• The GoF list of patterns.

Administrivia

Upcoming Work

• No reading for Wednesday! (No reading for Friday, either.)
• Reading Journal for Wednesday (due Tuesday at 11pm)
  • Subject: Reading Journal for Class 21 (Your Name)
  • If you could share two ideas or concepts from this class about software design with your successors in future offerings, what would they be?
  • What is your prospective topic for the ethics essay? Why?

Good Things to Do

• Get enough rest.

Design Patterns

• Inspired by C. Alexander's work on Architecture, A Pattern Language.
• Leading OO-programmers/designers looked at common software architecture tasks/problems and came up with a taxonomy of common solutions to those problems.
• Valuable in (at least) two ways
  • For novice programmers, provides better approaches to tasks that they don't realize are old.
  • For experienced programmers, provides a language to talk about approaches.
• There are growing movements to write "patterns" (and "anti-patterns") for many different classes of problems. There are even teaching patterns.
• Most folks at Grinnell believe that you apply patterns loosely; they are intended as a way to help you think and communicate, rather than strict strategies.

Reading Reflections

See the eboard.

Patterns

Creational

• Abstact Factory
• Factory Method
• Singleton
• Prototype
• Builder

Structural

• Adapter
• Proxy
• Facade
• Bridge
• Decorator
• Composite
• Flyweight

Behavioral

• Template Method
• Strategy
• Observer
• Iterator
• Visitor
• State
• Chain of Responsibility
• Mediator
• Interpreter
• Command

More Smells

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