Module Overview

This week you will learn about information hiding, which is both a benefit of abstraction barriers and a way to enforce abstraction barriers. We'll start by discussing interchangeable parts and testing. You will learn to distinguish between glass-box and black-box testing, which will help you to understand how interchangeability of parts depends upon abstraction barriers and information hiding. You will also learn benefits and limitations of execution-based testing.

Course Map

Readings

No readings yet.

Resources

• Improved information hiding in our Stack<E> ADT:
  1. Stack1 is the original version with a couple of new tests:
     • TestStack.java
  2. Stack2 removes the public keyword where possible:
     • StackBase.java
     • EmptyStack.java
     • Push.java
  3. Stack3 adds the private keyword where possible:
     • Push.java
  4. Stack4 moves implementation-specific class into the Stacks class
     • Stacks.java
  5. Stack5 declares nested classes private
     • Stacks.java
• Java interface for SearchableString.java
• video excerpts of class discussion:
  • traditional versus modern construction of pocket knives
  • why doesn't FMap's toString method reveal the keys?
  • what's that static <K,V> about?
  • isn't it better to remove debugging code from production code?
  • what's the point of testing a boolean constant?
  • preserving the red-black invariants

Lessons

1. Interchangeable Parts
2. Testing
3. Hiding Information Can Protect Clients

Homework Assignments

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To complete these assignments, you'll need to use the SearchableString.java Java interface linked above under Resources.

• a black-box test program
• implementation of a simple ADT