EBoard 20: Local bindings (Section 3)

Please follow the standard start-of-class routine. Make sure to grab a sheet of paper from the back.

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

Approximate overview

• Administrative stuff
• Pop quiz
• Lab

Administrative stuff

Introductory Notes

• I’m continuing the “limited talk” experiment.
• Some folks have asked whether I’ll have office hours during break. I hadn’t intended to, but I was planning to be on campus for some of break anyway, so I’ll be happy to meet during office hours (and, perhaps, other times).
• Quick notes on Friday’s new quizzes:
  • Testing: I’ll give you the description of a function and ask you to write ~3 “normal” tests and ~3 “edge” tests.
  • Local bindings: I’ll give you a function with repeated code and ask you to rewrite it with local bindings to get less/no repetition.
• Sorry about the confusion on the MP2 redo and the MP3 posting. I was experimenting with autograders (and failing).
• To encourage folks to memorize procedures (which you should be doing), I’m going to give a “pop quiz” on each Monday and Wednesday. You’ll get five questions (e.g., “What are three procedures that make lists?”) and five minutes to answer the questions. Every ten correct answers earn you an extra token.
  • If you didn’t grab a sheet from the back of the room, raise your hand and the mentor will bring you one.

Upcoming work

• Due Thursday, 2026-10-15
  • Readings:
    • List composition and decomposition
    • Submit reading response on Gradescope
  • Submit today’s lab on Gradescope
  • Mini-project 3
    • Submit on Gradescope
• On Friday, 2026-09-16
  • NEW Quiz/LA on testing (Monday’s topic)
  • NEW Quiz/LA on local bindings (todays’s topic)
  • 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
• Due Sunday, 2026-10-25
  • Nothing!
• Due Tuesday, 2026-10-27
  • Mini-project 2 redo
    • Submit redo on Gradescope
    • When submitting a mini-project redo, please include a file called CHANGES.txt that describes what you’ve changed.
    • If you don’t submit the CHANGES.txt file, they won’t grade it.

Upcoming activities

Scholarly

• Thursday, 15 October 2026, 11:00 a.m.–noon, JRC 101. Scholars’ Convocation: Unknown Topic
• Tuesday, 27 October 2026, Noon–1:00 p.m., CS Commons. CS Table

Artistic/Cultural

• Any day. Visit the GCMOA for at least 30 minutes.
• Thursday, 15 October 2026, 4:00–5:00 p.m., HSSC S1325. Writers@Grinnell presents Maya Binyam New
• Thursday, 15 October 2026, 8:00–9:00 p.m., JRC 101. Writers@Grinnell presents a reading and Q&A with Maya Binyam New

Multicultural

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

Peer

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

• Saturday, 24 October 2026, 1:00 p.m.–4:00 p.m., Rosenbloom Field. Football vs. Cornell College

Wellness

• Wednesday, 14 October 2026, 4:15–5:45 p.m., Undisclosed Location. Forest Bathing (two tokens) New
• Monday, 26 October 2026, 8:00–9:00 p.m., Prayer Garage in the CRSSJ. Meditation Group
• Tuesday, 27 October 2026, 4:30–6:00 p.m., Bear P103. Wellness Yoga

Misc

• Fill out the College AI survey at https://bit.ly/ACM-AI-Survey. There’s no need to submit evidence; just a reflection. New
• Wednesday, 14 October 2026, 8:00–9:00 p.m., Science 3820. Mentor Session
• Thursday, 15 October 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, 16 October 2026, 6:00–8:00 p.m., RKO Natatorium. Swimming and Diving vs. Augustana
• Saturday, 17 October 2026, 11:00 a.m.–1:00 p.m., Springer Field. Men’s Soccer vs. Lawrence University
• Saturday, 17 October 2026, 1:30–3:30 p.m., Springer Field. Women’s Soccer vs. Lawrence University
• Sunday, 18 October 2026, 2:00–4:00 p.m., Springer Field. Men’s Soccer vs. Gustavas Adolphus College

Pop quiz!

Here are today’s questions …

• Lists: List four procedures (other than the big three) that you can use with lists.
• Anonymous functions: Rewrite (lambda (x) (string-append x "X")) with l-s or r-s.
• Lists: What should (range 5 -3 -1) return?
• Lists: What function do you use to get the first n elements of a list?
• Numbers: What’s the difference between / and quotient?

Lab

Make sure the Scheme file has the semester in it (2026Fa). Reload if it doesn’t.