CSC 160 Fall 2014 - CW4 (extra credit: 50 points max)
Start in class on W 11/19, Finish outside of class by W 12/10

DIRECTIONS
1) In the spirit of the pair programming article that you read and summarized in HW5, you may do this assignment in pairs of two students. Do not pair up with the same student as any of the previous CW or HW assignments!
2) You must follow the Design Recipe in order. Do not start any step until you have completed all previous steps!
3) You need to submit one copy of your Definitions Pane through Moodle with the filename "cw4LASTNAMESdef.rkt". Make sure both names appear as a comment at the top of the Definitions Pane.

THE ASSIGNMENT
[20 pts.] Exercise 9.2.3 from the textbook. (Show all Design Recipe v1 steps - no data analysis or added details.)
[15 pts.] Exercise 19.3.2 from the textbook. (Add an example using check-error to test that this works.)
[15 pts.] Exercise 19.3.5: Write a third version of chop-first-char so that if the input is a non-string, it produces the error message chop-first-char: can't chop from a non-string and never returns. (Test with check-error.)

GRADING
Question	Point Value
9.2.3	20
19.3.2	15
19.3.5	15
TOTAL	50

Last Modified: 12/3/14