CSC151 2007S, Class 42: Association Lists and Searching

Admin:
* We'll begin today's class with a moment of silence.
* Due: HW 13 (free extensions)
* Assigned: HW14
* Wednesday's reading is also ready.
* EC: Game against central today, 2:30-5:30 at the baseball fields

Overview:
* Databases and dictionaries.
* Lists as dictionaries.
* assoc, a procedure for searching lists.
* Variants of Association Lists.
* Lab.

/Review of Reading/

* There are procedures that let you search lists by "key"
  * It's a lot like the test questions
  * You have a list of lists
  * This procedure that does the searching is called assoc
    (assoc key list-of-lists)
  * Keys can have any type
  * assoc only looks at the first element of each list in deciding
    whether or not the key matches
* Trivia
  * assoc uses equal? to decide if the key matches the car of the entry
  * assv uses eqv? to decide if the key matches ...
  * assq uses eq? to decide ...

/Lab!/

/Reflections/