Overview

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

Preliminaries

Admin

• Continue partners (also HW partners).
• Friday PSA.
• Good luck ST!

Reminders

• Office hours: MTWF 10-11, Tu 1-2.
  • Sign up at http://rebelsky.youcanbook.me.
  • Also feel free to stop by when my door is open.
  • Or to email me for an appointment.
• Tutor hours
  • Sunday, 3-5 p.m.
  • Sunday-Thursday, 7-10 p.m.
• Weekly review sessions:
  • Wednesday at 8pm in the CS Commons with
  • No Thursday review session next week .... :-(
  • Thursday at 8pm in the CS Commons with

Upcoming Work:

• Reading for Monday
  • Anonymous Procedures
• Assignment 5 due next Tuesday at 10:30 p.m.
• No writeup today!

Extra Credit

• Send your reports to rebelsky@grinnell.edu with subject "CSC 151 Extra Credit". (Do not include the quotation marks.)
• Send opportunities to me before class with subject "CSC 151 EXTRA CREDIT OPPORTUNITY!"

Academic / Artistic

• CS Table, Tuesday, Apple vs. the FBI.
• Met Opera Simulcast, Saturday, March 5.

Peer

• Too much tonight! Try to do at least one of these things.
• Pun Club Tournament Friday the 26th 8pm under bob's.
• Contra Dance Friday the 26th 7:30-10:00 mainly in the main lounge
• AppDev Pub Night, Friday, 8pm-10pm, Lyle's (JRC Basement).
• Black History Month Showcase, Friday, Harris, 7:00-9:00 p.m. (JB performs aftger 8)
• 7:30 p.m Seven-Day Film Chalenge, in the Wall
• Improv Show the 27th 7:30 until we feel like we're done in Loose Lounge.
• Vote for SGA positions.
• Special Campus Council Meeting About Posse Situation, 4pm in ARH 102.

Regular Peer

• Social Dance Workshop Tuesdays 7:00-8:00 in Bucksbaum Dance Studio
• Pun club Saturdays at 4pm in Younker
• Electronic Potpourri on KDIC Fridays at Five
• Space Odyssey KDIC Fridays at Six

Misc

• Christine Tran show in Smith Gallery.

Far in the Future

• Lords of the Flies, April.

No Extra Credit, But Still Good

• Regional diving at noon tomorrow.

Questions

Can you clarify the difference between test-case and test-suite.

Both groups tests/checks together.

test-suites are delayed; only run when you say run-tests

test-cases, unless nested in test-suites, run immediately

Irrelevant for today's quiz

Is cond just like if but with extra brackets?

cond does more tests!

> (define classify
    (lambda (number)
      (if (< number 60)
          'f
          (if (< number 70)
              'd
              (if (< number 80)
                  'c
                  'b)))))
> (classify 85)
'b
> (define classify
    (lambda (number)
      (cond
        [(< number 60)
         'f]
        [(< number 70)
         'd]
        [(< number 80)
         'c]
        [else
         'impossible])))

Why do I get #f for (and (= 2 3) (/ 3 0)) but an error if I write (and (= 2 2) (/ 3 0)).

and evaluates each expression in turn. If the expression is false, and returns immediately. Otherwise, and moves on to the next expression. If any of the expressions it hits gives an error, and gives an error.

Quiz

Lab

No writeup today!