CSC151.02 2003F, Class 49: A CGI Project

Admin:
* Exam 3 ready (more or less).  Sorry that it took so long.
* Read "Records in Scheme"
* Congratulations to Sung-Ju for getting a letter-to-the-editor published in the world-renowned Des Moines Register.  (Development in developing countries.)  Extra credit for finding and reading his editorial.

Overview:
* Why are we learning this stuff?
* What did we learn, anyway?
* Project: Simple database search

Questions on the Exam
Q: Do recursive procedures have to be tail-recursive?
A: No
Q: Will we receive extra credit for making them tail recursive?
A: Maybe
Q: What happens if we write kernels that are not local?
A: You will lose style points. 

Why are we learning CGI?
* So that we can make Web pages that "do cool stuff".
* So that we can write programs that other people can interact with without getting a Linux account or learning how to start DrScheme or both.
* It's a different way of using Scheme; it may be harder to find errors, so it exercises your brain in a different way.
* It might even be fun.

Review: What did we learn?
* How to take a variable and create a Web site that is tailored to the user.
  * Sam's silly diagram of the process.
* In the HTML page
	<form method="get" action="url">
	<input type="text" name="...">
	</form>
* In the Scheme part of the CGI script
	(get-cgi-variable "...") ; The thing in ellipses must match the thing in ellipses in the HTML page.
* Your goal is to write a procedure, (page), that reads variables and generates an HTML page.

Exercise: Combine these ideas with stuff we've done recently (e.g., searching).
Write a simple Web-based information retrieval application.
* Countries and their capitals. 0
* People and their grades. 2
* Beverages. 5
* Grinnell students and interesting facts about those students, such as their majors. 8

For each student, we will store:
* 0: First name
* 1: Last name
* 2: Nickname
* 3: Home
* 4: Major
* 5: Class/year

We can represent each student as a vector.

We can represent all students as a list of those things.

* Can we search the list of students by first name?
(define search-students
  (lambda (...)
    ...))

To build an application, we need to get a request from the user, search the students, turn the student records to HTML, and show the result.