--- title: Eboard 08 Testing your procedures number: 8 section: eboards held: 2017-09-11 --- CSC 151.03, Class 08: Testing your procedures ============================================== _Overview_ * Preliminaries * Notes and news * Upcoming work * Extra credit * Notes on the quiz * Questions * Lab * Debrief ### News / Etc. * New places/partners! * Quizzes returned. * Homework returned, too (at least for some of you). * And even some labs. * I'm still working on catching up. Sorry. "The best laid schemes" and all that. ### Upcoming Work * [Writeup for class 7](../writeups/writeup07) due TONIGHT at 10:30 p.m. * Document `take` * To: * Subject: CSC 151.03 Writeup 7 (YOUR NAMES) * [Assignment 3](../assignments/assignment03) due Tuesday. * [Writeup for class 8](../writeups/writeup08) due Wednesday at 10:30 p.m. * Exercises 3d and 6. * To: * Subject: CSC 151.03 Writeup 8 (YOUR NAMES) * Read: [Heterogeneous lists](../readings/heterogeneous-lists) for Wednesdays's class. * Read: [Representing tables](../readings/tables) for Wednesdays's class. ### Extra credit (Academic) * CS Table, Tuesday, noon: Machine Ethics. (Info on Friday's eboard.) * CS Extras, Thursday at 4:15 p.m. in 3821. A UI for Chemical Reaction Networks. ### Extra credit (Peer) * ??? ### Extra Credit (Misc) * Time Management Workshop, Tuesday, 11am, JRC 226. * Host a prospie (future) ### Other Good Things * Men's Soccer vs. Buena Vista, Sept. 17 at 2:00 p.m. ### Quiz 2 * Wide distribution of scores, not correlated with prior experience. * Some struggling with syntax. Some struglling with so many things at so many different levels. Notes on definitions from part 1 ``` ; cat is a procedure that doubles its parameter (define cat (section * <> 2)) ; mouse is a procedure that increments then doubles (define mouse (o cat increment)) ; The section adds 5 ; So moose adds 5 and then computes the square root (define moose (o sqrt (section + <> 5))) ; squirrel is 11 (define squirrel 11) ``` Interactions ``` > squirrel 11 > (mouse 5) 12 > (moose squirrel) 4 > ((section - <> 2) 5) 3 > (map (section - <> 2) (list 1 2 3 4 5)) '(-1 0 1 2 3) > (5 (section - <> 2)) ; 5 is not a procedure . . application: not a procedure; expected a procedure that can be applied to arguments given: 5 arguments...: > (map cat (iota 6)) ; (iota 6) => '(0 1 2 3 4 5), cat doubles '(0 2 4 6 8 10) ``` Use `string-append` to define a procedure that takes one input and generates "Hello .... How was your day?" ``` (define greet (lambda (name) (string-append "Hello " name ". How was your day?"))) ``` With section ``` (define greet (section string-append "Hello " <> ". How was your day?")) ``` ### Questions Why is there food in the back of the room? : I'm tasked with feeding folks in a once-per-month meeting. I bring my post-meeting class leftovers. How should we indent? : When you think it would be clearer to see the parameters separated one per line : When your lines are getting really long (> 80 columns) How much should we indent? : Trust DrRacket. : Ctrl-I reindents. What are some Ctrl things I should know? : Ctrl-S - Save (it will crash; save early and often) : Ctrl-up-arrow - Previous (escape p) : Ctrl-down-arrow - Next (escape n) : Ctrl-R - Run (the definitions pane) : Ctrl-Enter - Execute current command in interactions pane, even if the cursor is not at the end of the command. : Ctrl-I - reindent The sections are out of synch : Computers are sentient and malicious, even to your sentient and malicious instructor. Do we have to document our procedures? : Of course. 4P's is often okay. But I turned in my assignment already. : That's okay, you have another 33 hours or so. Should we break longer procedures into smaller ones? : Yes, it tends to clarify things. But I don't like documenting. : Deal. What if I give some E's and some F's? : Talk to me. (or send me email) Lab --- I'm not quite sure what you want in 3d : Force reload; there's a hint. Why did you make us write 13 (epsilon of 2) different explanations in 3d? : Past experience suggests that students don't think carefully enough about the range of things they might test. Past experience also suggests that if I only ask you to talk through it, you'll think you get it, but won't. This one painful exercise is intended to help you think more carefully. Debrief ------- Observation: Although Sam suggested test suites, you can put checks directly in your code, and that way you'll see errors when you click run. * Yes, that works, too. Things Sam hopes you took away from today's class. * Writing some simple tests is not much harder than just doing experiments, * You can write checks even without a test suite. * On the other hand, writing a comprehensive test suite is hard. You need to think about lots of things that can go wrong. * I still write test suites that miss some of the strange things in the code of the folks I am testing. * That thinking is often helpful, as it lets you reflect more on what the procedure is supposed to do independent of the code you've written. * Consider writing tests before code. * You do so mentally, anyway. "What should my procedure output on an input of 3?"