• New Partners!

Overview

• Preliminaries.
  • Admin.
  • Upcoming Work.
  • Extra Credit.
  • Questions.
• Lab.
• Debrief.

Preliminaries

Admin

• Grades distributed via email.
  
  • Yes, I take comments and corrections.
  • No, you can't now do the labs you missed.
  • As some of you have discovered, I didn't catch all absences, but I caught many, and absences do affect your grade.
  • I have promised a number of people that I will revisit their exam 2 grade at the end of the semester and see how much of an impact dropping it has had. I will do so for anyone who asks me during finals week.
  • HW grades coming.

Upcoming Work

• Lab writeup (paper!): Exercises 1 and 3
• Reading for Tuesday: Trees
• HW7 due Tuesday at 10:30 p.m.
• Exam 3 distributed Wednesday.

Extra Credit Opportunities

Academic

• Joe Palca talk Tuesday at 7:30 p.m. in Sebring-Lewis.
• Scholars Convocation Wednesday at noon: Alison Bechdel.
• CS Extras Thursday: ???
• CS Table Friday: ???

Peer Support (Morning Section)

• KY's radio show, "We Think We're Funny", 9-10pm Mondays. (Remember that Sam thinks he's funny, too, and KY is is from MN.)
• Julia's radio show, "The Hot Box". Wednesday night/Thursday morning 1:00-2:00 a.m.
• Host an admitted student this coming Sunday night (and the following weekend)! Contact JMU for info.

Miscellaneous

Nothing at present

Other Good Things (no extra credit)

• Student research seminar this week.

Questions

Lab

• A call to cons creates a box; a call to null does not
• Draw cons boxes
• When you have a null, put a slash in the box where the null is referenced
• When you have a non-null, draw the value separately and draw an arrow TO it.
• Most calls to list create pairs.

Debrief

• Lists of length N have a "spine" with N pairs.
• Why do we do this?
  • Because we will be building more complex structures.
  • Because we want to understand how things work.
  • Because it makes a difference when you start doing some stranger things (at least in theolder verseions of Scheme)