CSC151, Class 40: Discussion of Exam 2

Overview:
* Some general notes on exam 2.
* From lists to strings.

Notes:
* Read "Tail Recursion"  I want to see a sea of hands when
  I ask "Who did the reading?"  (I'd prefer equally many
  when I say "Who understood the reading?")
* Project, phase 2.
* What did you think of today's talk?
* Admitted students may be visiting today.
* Meeting in Saints' Rest.  Warning!  I'm a visual
  thinker, so may run a verbal class oddly.
* Work left in CSC151: Project, Exam 3, Optional Final,
  Regular readings
  + No other homework