Held: Monday, 5 May 2014

Back to Outline 52 - Objects in Scheme. On to Outline 54 - File Basics.

Summary

We continue our exploration of objects in Scheme.

Related Pages

• Reading: Building Objects in Scheme
• Lab: Building Objects in Scheme
• EBoard 53 (Source 53) (HTML 53) (PDF 53)

Overview

• Objects, revisited.
• Building a four-way switch.
• Reflection.

Administrivia

• Exam 3 returned.
• Today: Finish learning object basics.
• Tomorrow: Files.
• Wednesday: Wrapup and evaluate.
• Friday (optional): Go over exam 3, prepare for final.
• Grading done: Exams, some quizzes.
• Grading to go: Projects, lots of daily writeups, extra credit.

Upcoming Work

• No more homework.
• Reading for Tuesday: Files in Scheme
• No lab writeup.

Extra Credit

• CS Table Friday: Informal chat.

Objects: Key Ideas

• Mutable, encapsulated data.
• Represented as functions.
• Functions take the action as their input.
• Data is represented as a local vector.
• No one else can access the vector.

Writing the Four-Way Switch

Feel free to ignore what I'm saying and just work on the lab.

• What messages?
• How should we represent the state?
• How should we change the state?

Lab

• If you finish early, do the extras.
• If you finish the extras, feel free to surf the Web.

Reflection

• What was the most interesting part of the objects exploration?
• Should we do this earlier in the semester?
• What was the most difficult part?