EBoard 24: Tail recursion (Section 3)

Please follow the standard start-of-class routine.

Warning! You are being recorded (and transcribed) (provided the technology is working correctly).

Approximate overview

• Administrivia (2:40)
• Lab (2:50)
• Quiz (3:30)
• Class ends (4:00)
• Bonus quiz time ends (4:30)

Administrative stuff

Introductory Notes

• Happy (almost) Halloween! There’s candy at the back of the room.
  • Obligatory Sam Halloween “joke(s)”.
• We’re still on the “Sam talks less” experiment.
  • We’ll check in about it on Monday.
  • I won’t record today since the “Sam talks less” doesn’t seem to require recording.
• Today’s lab is much too long, even with “Sam talks less”. We will continue it on Monday, but with different partners.
• Don’t forget that clocks stop for one hour at 2:00 a.m. Sunday
  • That is, we “fall back” to move from Daylight Savings Time to Standard Time.
• Observation: It is good practice to have a list of procedures you’ve written or seen so that when you get a similar problem, you can base your solution to the new problem on your solution to the earlier problem.
  • product is a lot like sum
  • tally-odd is a lot like tally-value
  • alphabetically-first is a lot like largest.

Upcoming work

• Due Sunday, 2026-11-01
  • New reading
• Due Tuesday, 2026-11-03
  • Mini-project 4
    • Submit MP4 on Gradescope
    • Don’t forget to send in questions!
• Due Thursday, 2026-11-05
  • Mini-project 1 second redo
    • Submit redo on Gradescope
    • When submitting a mini-project redo, please include a file called CHANGES.txt that describes what you’ve changed.
• On Friday, 2026-11-06
  • NEW Quiz/LA on tail recursion (today)
  • NEW Quiz/LA on numeric recursion (Monday)
  • Makeup Quiz/LA on list recursion
  • Makeup Quiz/LA on testing
  • Makeup Quiz/LA on local bindings
  • Makeup Quiz/LA on collaboration
  • Makeup Quiz/LA on lists and list operations
  • Makeup Quiz/LA on conditionals
  • Makeup Quiz/LA on compose, cut, and section
  • Makeup Quiz/LA on tracing
  • Makeup Quiz/LA on decomposition
  • Makeup Quiz/LA on procedures

Upcoming activities

Scholarly

• Tuesday, 3 October 2026, Noon–1:00 p.m., JRC 224C (I think). CS Table
• Thursday, 5 October 2026, 11:00 a.m.–Noon, JRC 101. Scholars’ Convocation: More Humanities

Artistic/Cultural

• Any day. Visit the GCMOA for at least 30 minutes.
• Saturday, 31 October 2026, 7:30–10:30 p.m., Harris Cinema. RHPS
• Saturday, 31 October 2026, 8:00–9:00 p.m., Gardner. James Ivy and Band
• Saturday, 31 October 2026, 8:00–9:30 p.m., Herrick. Halloween “Spooktacular” Organ Concert (I’m not sure which organs they are playing; perhaps hearts and lungs.)

Multicultural

• Friday, 30 October 2026, 4:10–5:00 p.m., HSSC N1170. Middle of Everywhere (Chinese Ghosts)

Peer

Musical, theatric, sporting, academic, and similar events involving this section’s students are welcome.

• Saturday, 31 October 2026, 6:30–6:35 p.m., Global living room. Jafar Shawarma

Wellness

• Monday, 2 November 2026, 8:00–9:00 p.m., Prayer Garage in the CRSSJ. Meditation Group
• Tuesday, 3 November 2026, 12:15–12:45 p.m., GCMoA. Yoga in the Museum
• Tuesday, 3 November 2026, 4:30–6:00 p.m., Bear P103. Wellness Yoga
• Tuesday, 10 November 2026, 5:00–8:00 p.m., HSSC North Auditorium. Therapy Dogs

Misc

• Fill out the College AI survey at https://bit.ly/ACM-AI-Survey. There’s no need to submit evidence; just a reflection.
  • Friday deadline.
• Wednesday, 4 November 2026, 8:00–9:00 p.m., Science 3820. Mentor Session
• Thursday, 5 November 2026, 8:00–9:00 p.m., Science 3820. Mentor Session

Other good things

These do not earn tokens, but are worth your consideration.

• Friday, 30 October 2026, 7:00–9:00 p.m. Darby Gym. Volleyball vs. Beloit
• Saturday, 31 October 2026, 11:00 a.m.–1:00 p.m., Springer Field. Men’s Soccer vs. Cornell College (last home meet of the season)
• Saturday, 31 October 2026, 1:00–3:00 p.m. Darby Gym. Volleyball vs. Lake Forest (senior day)
• Saturday, 31 October 2026, 1:30–3:30 p.m., Springer Field. Women’s Soccer vs. Cornell College (last home meet of the season)

Friday PSA

• You are awesome! Please take care of yourselves!
• Decide what is right for you in advance; don’t succumb to pressure or expectations.
• Moderation!
  • I don’t care that it’s the last Saturday Halloween for a decade; I still expect you to be moderate.
• Consent is essential. Consent is insufficient. Consent is impossible when impaired (no matter what NY law says).

Lab

We’ll be continuing the lab on Monday (probably starting with exercise 4), but with new partners.

Quiz