Module Overview

Some problems are not easily solved using our usual observer templates. Others are solved only inefficiently by following those templates. We introduce two new kinds of generalization to help solve such problems. We introduce invariants as a way of recording the assumptions that a function makes about its environment.

Course Map

Readings

Read Part VI from our textbook. We are doing things in a different order than the textbook. We are also doing this topic rather differently, so use the textbook as background rather than as a normative reference.

Resources

• Examples for Module 07

Lessons

• Lesson 7.1: Solving Your Problem by Generalization
• Lesson 7.2: More Examples of Invariants
• Guided Practice 7.1
• Lesson 7.3: When do I need an invariant?
• Lesson 7.4: Case Study — Undefined Variables in GarterSnake
• Guided Practice 7.2
• Guided Practice 7.3
• Lesson 7.5: foldr and foldl

Problem Set

Problem Set 07 was assigned on Monday, 27 February.