Assigned: Friday, October 11, 2002
Due: Friday, October 18, 2002
Contents
Summmary:
In this homework assignment, you will build a simple Web service that
allows someone to enter some basic information about an author (name,
year of birth, year of death) and receive a list of contemporaries that
the service knows about.
There are three parts to the assignment. In the first part of the
assignment, you will build the Scheme functions that can be used
to identify contemporaries. In the second part, you will build the
Web interface. In the third part, you'll test your work using some
simple inputs.
Purposes:
To give you more exprience writing procedures that extract data from
lists. To give you more experience relating your Web/CGI knowledge to
your Scheme knowledge.
Collaboration: You should work in groups of two
or three. You may not work alone (this means you, Phil). You may
not work in groups of four. You may discuss your work and the
assignment with anyone you wish. You may obtain help from anyone
you wish, but you should clearly document that help, preferably in
the introductory comments at the top of the page.
Associated file:
Let's say that two authors were contemporaries just in case both
of them were born before either of them died. Thus, for instance,
Gabrielle D'Annunzio (1863-1938) was a contemporary of Flannery O'Connor
(1935-1964), but not of Thomas Malory (d. 1471).
In this exercise, you will design, document, and write a Scheme
procedure named contemporaries that takes information
about an author (in the form of a three-element list comprising
the author's surname, year of birth, and year of death) and a
database of authors, and then searches through the database for
contemporaries of that author, and returns a list of the names of
any contemporaries that it finds. You may also write any helper
procedures that you need, but you must comment every procedure that
you write.
Here is what a typical interaction with this procedure should look like.
The user wishes to see a list of the contemporaries of Francis Bacon
(1561-1626).
> (contemporaries '("Bacon" 1561 1626) list-of-authors)
("Bradstreet" "Cervantes" "Corneille" "Donne"
"Jonson" "Marlowe" "Milton" "Moliere" "Montaigne" "Ronsard" "Shakespeare"
"Spenser")
In the file authors.ss,
you can find a modest database containing the surnames or pseudonyms of various
authors and their dates of birth and death. Again, each surname is given
as a Scheme string literal and each date as a Scheme integer, and these
three data about each author are assembled into a list. The database is a
list of such three-element lists and is named list-of-authors.
You may include this definition in your program.
The contemporaries procedure should compare its argument
successively to each entry in the database. Whenever it detects a
contemporary, it should select the surname or pseudonym from the database
and add it to the result list.
Build a Web-based interface for contemporaries. Your
interface should allow someone to enter information on an author in
a Web form (last name, date of birth, date of death), click on a button,
and get a nicely displayed list of contemporaries.
It is likely that you will need to create three files,
- a Web page (in HTML) for the form;
- a Scheme program that processes the data from the form,
calls
contemporaries, and converts the result
to HTML;
- and a small CGI file that runs the Scheme program.
Your Scheme program will probably need to include procedures that
turn an individual author entry into HTML and that turn a sequence of
author entries into HTML.
Note that you may want to consider building a variant of
contemporaries that returns a list of matching entries,
rather than a list of names. (You should still keep the original
version of contemporaries somewhere in your program,
even if you don't use it.)
Use your program to find the contemporaries of
- Pierre-Augustin Caron de Beaumarchais (1732-1799)
- James Gould Cozzens (1903-1978)
- George Farquhar (1678-1707)
- André Maurois (1885-1976)
- William of Malmesbury (1090-1143)
- Frank Zappa (1940-1993)
Thursday, 10 October 2002 [Samuel A. Rebelsky]
- Created. The first part and the list of authors were taken from
(by John David Stone and Benjamin Gum). That version was last
revised 26 Sepember 2002.
- Added Web interface component and summary.
- Moved sample data elsewhere.
- Reformatted.
Friday, 11 October 2002 [Samuel A. Rebelsky]
;
Check with Bobby