---
title: Eboard 09  Boolean values, predicate procedures, and conditionals
number: 9
section: eboards
held: 2019-02-13
link: true
---
CSC 151 2019S, Class 09:  Boolean values, predicate procedures, and conditionals
================================================================================

_Overview_

* Preliminaries
    * Notes and news
    * Upcoming work
    * Extra credit
    * Questions
* About exam 1
* Lab

Preliminaries
-------------

### News / Etc.

* Mentor sessions Wednesday 8-9 p.m., Thursday 8-9 p.m., Sunday 5-6 p.m.
* The mentors want you to know that it's relatively easy to find documentation
  for regular expressions online.  (There are slight differences in RegExp
  syntax, but not many.)
* On Friday, I will distribute the final [class code of 
  conduct](../handouts/code-of-conduct).  
* Congrats to your classmate who I hear placed second on bar at 
  a recent AAU gymnastics meet.  
* I'm going to try to limit Q&A time so that we have enough time for lab.
* Advance warning!  We'll have a guest speaker at the start of class on
  Friday.  We'll have the quiz after she's finished.

### Upcoming work

* Readings due before class Friday
    * [Documentation, revisited](../readings/documentation-revisited)
    * [Verifying preconditions](../readings/preconditions)
* [Exam 1](../exams/exam01) due Tuesday night.
    * Details to be discussed later.
* [Flash cards](../flashcards/flashcards04) due Wednesday at 8:00 p.m.
    * Covers Wednesday/Friday/Monday classes
* [Lab writeup](../labs/writeup09) due before class Friday.
    * Exercise: 5
    * Subject: CSC 151.01 Writeup for Class 9 (YOUR NAMES) 
    * To: csc151-01-grader@grinnell.edu
* Quiz Friday
    * Regular expressions
    * List operations

### Extra Credit

#### Extra credit (Academic/Artistic)

* Convo Thursday at 11 (JRC 101): John Hassard, founding associate director
  of the Institute for Security, Science, and Technology at Imperial
  College London, will present, "Envisioning the Post-Hydrocarbon World"
* CS Extras, Thursday, 4:15 p.m. Science 3821: Summer Code Camps.
  (Snacks at 4pm in the CS Commons.)
* Any Data Week activity this week.
* HackGC weekend of 15-17 February 2019.  (I'm still looking for links.)

#### Extra credit (Peer)

* Conference Swim and Dive meet, 15-17 February 2019.  Dive times to
  be announced later.  (noon or 1, 7pm, Fri and Sat)
* Lunar New Year Celebration, 6pm February 17, Harris Gym

#### Extra credit (Wellness)

* HIIT training, 4:30 pm, Tuesday, Dance Studio, Bear.  (Cap of two EC units.)
* HIIT training, 10:00 am, Saturday, Dance Studio, Bear
* Hatha Yoga, 7:00 pm, Tuesday, Dance Studo, Bear.  (Cap of two EC units.)
* Brazilian Jiu-Itsu, Wednesday and Friday, 6:30, Dance Studio (cap of two
  EC units.)
* Any Sex Week activity this week.  (If you don't feel comfortable telling
  me about the particular activity, you can just say that you participated
  and give a vague reflection.)

#### Extra credit (Misc)

* Host a prospie! (Details forthcoming.)

### Other good things 

### Questions

I've hosted a prospie already, can I get extra credit?

> Sure.

What are the caps?

> Complicated.

About Exam 1
------------

Will you reward especially nice solutions?

> Possibly.  Probably.

What should our log look like?

```text
; Time Log:
;   Date        Start   Finish  Elapsed Activity
;  2019-02-13   13:00   13:10   10      Read the problem, drew a picture
;  2019-02-15   13:00   13:30   30      Wrote a procedure that ...; watched X dive
;  2019-02-17   19:00   19:10   10      Wrapped up the work

; Time Spent: 50 minutes
```

Lab
---

How do I check if a string starts with a capital letter?

> Use `(regexp-match? pattern string)` or `(regexp-match-exact? pattern string)`

What about "at the start of the word"?

> See the `p-words` instruction.  A caret not in the square brackets means 
  "start of string" (or, sometimes, start of line")

And "end of the string"?

> Google says that $ is the regexp for end of string/line.