Course News

• The first two assignments (Assignments 0 and 0.5) must be done individually; they are warm-up exercises solely designed to help you learn the fundamentals of Scala. The first assignment covering course material (the principles of programming languages) is Project 1. Project 1 and all subsequent assignments should ideally be done in pairs. So you should think about identifying a programming partner starting September 5.
• Please join the course mailing list by subscribing.
• If you haven't found a partner by September 5, send an email to the comp411-l mailing list.
• Students looking for Project 1 partners:
  • None yet listed.
  Please get in touch with each other. Issues to keep in mind:
  • Make sure you have the time to work on the project together.
  • Make sure that you team has some functional programming experience (e.g., Scheme, ML, writing in Java in a functional style) and some Java programming experience.
  • Try to find a permanent partner for the rest of the class; it's a lot easier to work with the same student than to switch.
  • You may choose to work alone. The work load is significant but manageable if you understand how to write mostly functional programs in Scala. We do not allow groups of more than two students, even if there is an odd number of students in the class.
  • If you haven't found a partner and are not on this list, send an email to the comp411 mailing list.
  • If you are on this list but have already found a partner, email the same list comp411 mailing list to remove you from this list.

Summary

COMP 411 is an introduction to the principles of programming languages. It focuses on:

• identifying the conceptual building blocks from which lanugages are assembled and
• specifying the semantics, including common type systems, of programming languages.

A secondary theme is software engineering. All of the programming assignments in this course are conducted in Scala using test-driven development and pair-programming, two of the major tenets of Extreme Programming. Scala is a putative successor to Java and runs on the Java Virtual Machine. Scala is fully compatible with compiled Java code. The Scala core libraries are an extension of the Java core libraries. In fact, it is possible to develop projects written partly in Scala and partly in Java, although we do not recommend using Java instead of Scala unless there is a strong external reason such as a project that extends an existing Java code base.

COMP 411 consists of three parts:

• The first part focuses on specifying the syntax and the semantics of programming languages. The former is introduced via simple parsing (translations) of program text into abstract syntax. More detailed aspects of parsing (such as lexical analysis and advanced parsing methods) are left to COMP 412, a course on compilers. The semantics of a comprehensive collection of programming language constructs is specified using interpreters and reduction (textual rewriting) systems. The constructs include arithmetical and conditional expressions, lexical binding of variables, blocks, first-class functions, assignment and mutuation, simple control constructs (loop exits, first-class continuations, simple threads), and dynamic dispatch.
• The second part illustrates how interpreters and reduction semantics can be used to analyze important behaviorial properties of programming languages. Two examples are covered: type safety and memory safety. Type safety guarantees that programs respect syntactically defined type abstraction boundaries and never raise certain classes of error signals. Memory safety guarantees that programs release memory if it is provably useless (using graph reachability [pointer-chasing] and perhaps more powerful techniques) for the remainder of the evaluation. Type safety typically implies on memory safety.
• The third part shows how interpreters can systematically be transformed so that they use fewer and fewer language facilities. The key transformations are the explicit representation of closures as records and the conversion of program control flow to continuation-passing style. Using these transformations, a recursive interpreter can readily be be re-written in a low-level language like C/C++ or even assembly language. These transformations can be applied both to interpreters and to arbitrary programs. if we apply these transformations to an interpreter, the result is a low-level interpreter that is easily implemented in machine code. The process of applying these transformations to arbitrary input programs yields a high-level description of program compilation, a process which is explored in more detail in COMP 412

Students who complete this course will be able to analyze the semantics and pragmatics of the old, new, and future programming languages that they are likely to encounter in the workplace (e.g., Fortran, C, C++, Java, Visual Basic, C#, Perl, Clojure, Groovy). They will also be able to build efficient interpreters for new languages or for "special-purpose" languages embeded in software applications. Finally, they will be much be equipped as software developers because they will understand how to define and implement whatever linguistic extensions are appropriate for simplifying the construction a particular software system.

Notes on the common mathematical notation used in operational semantics, some of which will be used in class.

Course Information

Please take a look at the course information some of which was discussed during the first few class lectures.

Assignments

Please refer to the assignments column in the below.

Lectures

Language Resources

1. Scala
   1. Getting started
      • A Tour of the Scala Language (created by Odersky's group)
      • Scala Distribution
      • DrScala
      • IDE Support
      • Simply Scala (online REPL)
   2. Quick References
      • Scala Cheatsheet
      • Scala API
   3. Online books
      • Programming Scala (O'Reilly OFPS – targets Scala v2.8)
      • Scala Handbook (中文/Chinese – targets Scala v2.8)
      • Programming in Scala, 1st ed. (targets Scala v2.7)
   4. Free Online course on Functional Programming in Scala by Martin Odersky
2. Java
   1. SDK Download
   2. API Reference
   3. DrJava Programming Environment
   4. Elements of Object-Oriented Program Design by Prof. Cartwright
3. Scheme
   1. How to Design Programs
   2. DrScheme Programming Environment
4. OCaml
   1. OCaml Book
   2. O'Caml Language
   3. MetaOCaml
   4. OCamlLex
   5. Using "Ledit" to make Ocaml recognize arrow keys
5. Haskell

Additional References

1. Krishamurthi, Shriram. Programming Languages: Application and Interpretation. Online at http://www.cs.brown.edu/~sk/Publications/Books/ProgLangs/. This book is a descendant of lecture notes created by Shriram for a version of this course when Shriram was a teaching assistant over a decade ago.
2. Friedman, Wand, and Haynes, Essentials of Programming Languages, 2nd ed. (MIT Press, 2001)
   You can take a look at the following two chapters, which the authors prepared for the second edition, without buying the book:
   1. Parameter Passing ( local file, PDF)
   2. Types and Type Inference ( local file, PDF)
3. Evaluation rules for functional Scheme ( PDF)
4. References on evaluating Jam programs
5. Lecture Notes on Types I
6. Lecture Notes on Types II
7. Introduction to System F (Polymorphic Lambda-Calculus)
8. Scheme code from Class Lectures
9. The Essence of Compiling with Continuations by Flanagan et al.
10. Uniprocessor Garbage Collection Techniques by Paul Wilson
11. Garbage Collection [canonical textbook] by Jones and Lins
12. Space Efficient Conservative Garbage Collection by Hans Boehm ( local file, PDF)
13. Hans Boehm's Conservative GC Webpage
14. The Java Virtual Machine. The most basic expository articles appear at the end of the index. Read it from bottom up.
15. Java Memory Model
16. Revised Thread Synchronization Policies in DrJava (doc) ( pdf). Since DrJava is built using the Java Swing library, it must conform to the synchronization policies for Swing. Unfortunately, the official Swing documentation is sparse and misleading in places, so this document includes a discussion of the Swing synchronization policies.
17. Lesson: Concurrency in Swing. This lesson discusses concurrency as it applies to Swing programming. It assumes that you are already familiar with the content of the Concurrency lesson in the Essential Classes trail.
18. Concurrency in Swing Text
19. The Last Word in Swing Threads
20. Old Course Website

Accomodations for Students with Special Needs

Students with disabilities are encouraged to contact me during the first two weeks of class regarding any special needs. Students with disabilities should also contact Disabled Student Services in the Ley Student Center and the Rice Disability Support Services.