MT3 review outline
------------------

General
    bring to the exam:
        your textbook
        mc-eval.scm
        homework solutions

Mutation
    DO NOT UNDERESTIMATE BOX-AND-POINTER DIAGRAMS, DRAW THEM FIRST!

    box-and-pointer diagrams
        ONLY CONS CREATES NEW PAIRS
            (... and things that use cons, e.g. list, quotation, ...)
        initial pointers
        a pointer to any part of a pair points to the WHOLE pair

    what are dummy elements like *table* for?
        using set! on local variables is useless
        why don't queues need one?

    what's wrong with this attempt at count-pairs?
       (define (count-pairs lst)
         (define (cp-helper lst pair-list)    ;; WRONG
           (cond ((not (pair? lst)) 0)
                 ((memq lst pair-list) 0)
                 (else (set! pair-list (cons lst pair-list))
                       (+ (cp-helper (car lst) pair-list)
                          (cp-helper (cdr lst) pair-list)
                          1) )))
         (cp-helper lst '()) )

    Spring 95 MT3 Q3. deep-map!
    Spring 96 MT3 Q2. list-rotate!
    Fall 96 MT3 Q2. merge!

Concurrency
    remember that different serializers do not protect against each other

    can we solve concurrency with software?

    abstraction:
         serializers
        -------------
           mutexes
        -------------
        test-and-set!

    issues
        correctness
        efficiency
        fairness
        deadlock
            when does deadlock occur?

Streams
    memoization

    (stream-filter even? (stream-filter odd? integers))

    how to merge two infinite streams?
        interleaving
        good technique for figuring out what recursively interleaved
         streams look like:
            if you know one of the interleaved streams, write it out with
             blanks between known elements, then fill in every other blank

            Fall 98 MT3 Q6. mystery

    good technique for generating streams in which each element depends on
     previous element
        stream-accumulate
        partial-sums

    Fall 94 Final Q4. random stream
    Spring 95 MT3 Q4. oz
    Fall 96 MT3 Q3. foo
    Spring 98 MT3 Q1. (1) (1 2) (1 2 3) (1 2 3 4) (1 2 3 4 5) ... stream

MCE
    special forms vs. primitives vs. compound procedures

    lexical vs. dynamic scope

    when making changes, what's relevant?