CS3 Fall 2005

1
CS3 Fall 2005

• Lecture week 15

2
Administrivia

• The final survey will be up tomorrow
• you NEED to do this to receive a grade on your
  project!
• Final
• Saturday, Dec 17th, 8-11 a.m.
• 155 Dwinelle
• Practice final in reader
• Study help
• Final review session Thursday, Dec. 15th, 8 pm
  11 pm.
• Wozniak Room, 430 Soda Hall
• Check the course portal announcements for
  additional office hours the week before the
  final.
• Send questions to Bobak, James, or Nate.

3
Nov 28 Lecture What is CS at Berkeley? (guests) Lab Big Project CHECKOFF 1 Tue/Wed (beginning of lab) CHECKOFF 2 Thur/Fri
Dec 5 Lecture Summary, other languages Lab Finish up the Project CHECKOFF 3 Tue/Wed Project Due on Thur/Fri
Dec 15 Final Review Session, 8pm-11pm
Dec 17 Final 8am-11am, 155 Dwinelle
4
The project

• Checkoff 3 is the next lab. The TA will run
  your code.
• Project is due at midnight on the day of your
  lab, this Thursday/Friday.
• Any questions about anything?

5
So, what have we done in CS3?

• Consider the handout of topics
• Common topics
• Pre-recursion
• Recursion
• Higher order procedures
• Lists
• Case studies
• Working with large programs

6
Another list

1. Functional programming
2. Functions as data
3. Recursion
4. Abstraction
5. Managing large programs

7
Another list continued

• Functional Programming
• All that can matter to a procedure is what it
  returns.
• Small functions can be easily tested (isolated)
• In other languages, you typically
• Perform several actions in a sequence
• Set the value of a global or local variable.
• Print, write files, draw pictures, connect to the
  internet, etc.
• Other "paradigms" sequential, object-oriented,
  declarative

8
Another list continued

• 2) Functions as data
• Higher order procedures will take functions as
  parameters.
• It is useful to return functions
• Lambda is quite useful

9
Another list continued

• 3) Recursion
• Linear (simple) to quite advanced
• In contrast to iteration and looping (where
  counters or state define looping constraints)
• Knowledge of recursion will help these simpler
  cases.

10
Another list continued

• 4) Abstraction
• The big idea that is related to everything!
• A design practice that makes it possible to carve
  up a problem, and therefore focus on only part of
  it.
• Makes working collaboratively more efficient

11
Another list continued

• 5) Managing large programs
• Style commenting, naming conventions, etc.
• Abstraction for maintenance and collaboration
• Iterative testing
• Reading the specifications, and communicating
  often with colleagues

12
How are you going to study for the Final?
13
The language Scheme

• Scheme allows you to ignore tedium and focus on
  core concepts
• The core concepts are what we are teaching!
• Other languages
• Generally imperative, sequential
• Lots and lots of syntactic structure (built in
  commands)
• Object-oriented is very "popular" now

14
CS3 concepts out in the world

• Scheme/lisp does show up scripting languages
  inside applications (emacs, autocad, Flash, etc.)
• Scheme/Lisp is used as a "prototyping" language
• to quickly create working solutions for
  brainstorming, testing, to fine tune in other
  languages, etc.
• Recursion isn't used directly (often), but
  recursive ideas show up everywhere

15
Java and PHP

• Java is a very popular programming language
• Designed for LARGE programs
• Very nice tools for development
• Gobs of libraries (previous solutions) to help
  solve problems that you might want solved
• PHP
• Popular course for web development (combined with
  a web-server and database)
• Lots of features, but little overall "sense"
• Because programs in PHP execute behind a
  web-server and create, on the fly, programs in
  other languages, debugging can be onerous.

16
SQL (structured query language for databases)
resembles HOFs

• query Tell me the names of all the lecturers
  who have been at UCB longer than I have.
• select name from lecturers where date_of_hire
  lt (select date_of_hire from lecturers where
  name 'titteton')
• query Tell me the names of all the faculty who
  are older than the faculty member who has been
  here the longest.
• select L1.name from lecturers as L1 where
  L1.age gt (select L2.age from lecturers as L2
  where L2.date_of_hire (select
  min(date_of_hire) from lecturers) )