Common Lisp!

1
Common Lisp!

• John Paxton
• Montana State University
• Summer 2003

2
Montana Geography

• The continental divide runs through the state of
  Montana in the Rocky Mountains. On the west,
  water flows to the Pacific Ocean. On the east,
  water flows to the Gulf of Mexico.
• The longest undammed river in the U.S., the
  Yellowstone River, is in Montana.

3
Montana Statehood

• Montana was the 41st state to join the United
  States. It did so in 1889.
• Bannock was the territorial capitol.

4
Iteration

• dotimes
• dolist
• do
• do

5
dotimes

• gt (setf sum 0)
• 0
• gt (dotimes (i 10 sum)
• (setf sum ( sum i))
• )
• 45

6
dotimes

• Question. Write a function that computes the
  Fibonacci numbers using dotimes.
• Question. Compile the above function and run it.

7
dolist

• gt (setf sum 0)
• 0
• gt (dolist (item '(1 2 3) sum)
• (setf sum ( sum item))
• )
• 6

8
dolist

• Question. Write a function called my-mapcar that
  is equivalent to mapcar. The function should use
  the dolist construct.

9
do

• (do
• (
• (local-variable-1 initial-value update)
• (local-variable-n initial-value update)
• )
• (termination-test intermediate-forms result)
• loop-body
• )

10
do

• gt (do
• (
• (sum 0)
• (counter 0 ( 1 counter))
• )
• ( (gt counter 10) sum )
• (setf sum ( sum counter))
• )
• 45

11
do

• Question Write a function that computes the
  Fibonacci numbers using do.

12
do

• do works just like do. The only difference is
  that the local variables are assigned initial
  values and updated in sequence instead of in
  parallel.

13
do

• Question Write a function that computes the
  Fibonacci numbers using do.