CSC 270
Survey of Programming Languages

Instructor: Dr. Stephen Bloch

Fall, 2011

This course meets from 9:25-10:40 AM on Tuesdays and Thursdays in Science 227.
The last time I taught this course was Fall 2010. A lot of this page is copied from last year; I'll make updates as I get to them.

Syllabus Calendar Grading Assignments PSP Moodle course Examples Daily Survey


Throughout the semester (ideally every few days), I'd like you to fill out the daily survey to help me keep track of what people are finding easy, and what people are having trouble with. This can also be used as an anonymous "suggestion box".

Getting Help

My office hours (in Post 203; if I'm not there, look in the computer lab in Post 102) are MTWTh 3:00-4:00 and W 9:30-1:00.

Who should take this course?

This course is intended primarily for students majoring or minoring in computer science or information systems. It assumes CSC 171 and 172 as prerequisites. If you're taking 172 concurrently with 270, you'll have a more difficult time, but you should be able to survive the course; talk to the instructor.

Subject matter

There are more details in the syllabus, but in brief, we'll learn bits of three languages --- Racket, Prolog, and Ruby --- that are new to most of you. We'll do simple exercises in each language to make sure we understand the basics, then do a a few more substantial programs in each language. And for more of an "under the hood" view, we'll write interpreters for some very simple languages, so we can see some of the subtleties involved in implementing a language.

In all languages, you will be expected to follow good general programming practices: give meaningful names for variables, types, and functions; use named constants for "magic numbers" that appear more than once in a program; provide test cases for all parts of your program; use white space and indentation as appropriate in the language to enhance readability; segregate I/O from computation as much as possible; write several small functions that do one thing each rather than a single big function that does many things; plan for re-use, modification, and extension; etc. If you're not sure what any of these things means, ask me -- ideally in class, as your classmates probably have the same questions.


Other Reading



There are several Scheme implementations available, but the one most widely-used in education is DrRacket, freely downloadable for Windows, Macintosh, Unix, etc. One of its nice features is language levels: if you're a "Beginning Student", you'll get error messages for certain things that are technically legal in Racket but which a beginning student doesn't need. If you decide you do need a certain feature, you can promote yourself to "Intermediate Student", "Advanced Student", etc. with a few mouse-clicks.

Some of the Racket we do will be in the PLAI dialect. To switch to this dialect in DrRacket,

  1. in the Language menu, select "Use the language declared in the source"
  2. change the #lang racket line at the top of the Definitions pane to #lang plai .

General Development Environments

I recommend Eclipse, a professional-level development environment which is available for free download and has "plug-ins" available to work with several different languages: Java, C, C++, Prolog, etc.

Another possibility is jGRASP, which is designed for first-year programmers and therefore has fewer "professional" bells and whistles, but provides a cute graphical annotation of the control flow of your program. It works best on Java, but it can support C, C++, and Ada as well.

I'm pretty new to Ruby myself, but you can download a Ruby compiler and environment from

We'll be using a free implementation of Prolog called "SWI Prolog". It should be installed on the machines in the lab.

Partners for upcoming assignments

If you need a partner for the next homework, please e-mail me immediately and I'll try to match you up with someone.

Software support

I've set up some forms for entering and viewing PSP data. You may use these forms to record defects, time allotted, time spent, and program size, but I won't require this information. To use the forms successfully, make sure your browser accepts JavaScript and cookies. (For those with a moral opposition to cookies, I assure you that they're all "temporary" -- they disappear as soon as you quit the browser.) (For more information about PSP, see the PSP page at Carnegie-Mellon or read Watts Humphrey's Introduction to the Personal Software Process.)

Last modified: Fri Sep 2 08:47:02 EDT 2011
Stephen Bloch /