This course has the purpose of introducing students who have had experience with basic data structures and algorithms to more advanced skills, concepts and techniques in programming and Computer Science in general. This will be accomplished along three dimensions.

• The main skill you will get out of this course is a logical attitude toward problem solving. You will learn how to decompose a problem into manageable parts, how to compose their solutions into a complete program, and how to reason about programs to ensure that they are correct
• As we do that, you will be exposed to some advanced but pervasive concepts in Computer Science and programming. In particular, you will learn about abstraction, induction and recursion, program correctness and verification, asymptotic cost analysis, parallelism, symbolic computation, search, structuring large programs, computability, streams, and more
• Our vehicle for achieving these objectives will be Standard ML, one of the most advanced experimental programming languages brewing in the labs worldwide. SML will expose you to a programming paradigm that is totally different from what you have seen in earlier classes, namely functional programming. This will give you first-hand experience with a number of high-level programming techniques such as recursion, data-centric computation, higher-order functions, data abstraction, polymorphism, exceptions and modularity. Bits and pieces are found in current commercial programming language such as Java, and more will be part of the programming languages of the future

After completing 15-150, you will be able to take 15-210 (Parallel and Sequential Data Structures and Algorithms) and 15-214 (Principles of Software System Construction).

You must have completed 21-127 (Concepts of Mathematics).

It is my goal to make this course successful, stimulating and enjoyable. If at any time you feel that the course is not meeting your expectations or you want to provide feedback on how the course is progressing for you, please contact me. If you would like to provide anonymous comments, please use the feedback form on the course home page or slide a note under my door. Comments of general interest will be answered on the course discussion board.

The course relies extensively on the programming language Standard ML (SML) and related utilities. The particular implementation we will be working with is Standard ML of New Jersey (SML/NJ), version 110.74.

SML on Your Own Laptop

The most convenient way to use SML is to install a personal copy of SML/NJ on your laptop. For Windows laptops, download this file and follow these instructions. If you run a different operating systems, read here. You will want to configure your favorite editor so that you can run SML directly inside it, not from a separate terminal window.

SML at CMU-Q

A reference build has also been made available in the virtual Unix clusters. To run it, you need to login into your Unix account. In Windows, you do this by firing PuTTy and specifying unix.qatar.cmu.edu as the machine name. When the PuTTy window comes up, type sml, do your work, and then hit CTRL-D when you are done.

You can edit your files directly under Unix (the easiest way is to run the X-Win32 utility from Windows and then run the Emacs editor from the PuTTy window by typing emacs - see also this tutorial).

If you want to do all this from your own laptop, you first need to install X-Win32 from here. PuTTy is pre-installed in Windows.

Documentation

Useful documentation can be found on the SML/NJ web site. The following files will be particularly useful:

• Using the SML/NJ System, by Peter Lee, answers the following question: Ok, I've got the SML prompt, now what do I do?
• The SML Basis Manual Pages describes the functionalities made available in the SML basis library

Latex

We strongly encourage you to typeset the essay part of your homeworks in LaTeX (we will take this into account as part of your participation grade). It takes some getting used to it, especially if MS Word is all you've been exposed to, but it enormously simplifies producing pleasant mathematics. Here are some useful references:

• The Wikibook on Latex
• A short long introduction to Latex2ε
• The Comprehensive TeX Archive Network

The 15-212 Wiki

The material for most of the lectures can be found on the 15-212 wiki. This is wiki, not a textbook. The main differences are:

• It is dynamic: the content will change over time (for the better)
• It will always be work in progress
• Everybody can make updates. This means YOU!

Further References

• Michael R. Hansen and Hans Rischel, Introduction to Programming Using SML, Addison-Wesley, 1999.
• Robert Harper, Programming in Standard ML, draft version 1.2

This is a 10 unit course.

• Daily exercises and Participation: 10%
  • At the end of the every lecture, you will be given daily exercises, a couple of simple exercises or questions collected during the next class. Each will be graded, with negative points for missing or sloppy work.
  • Participation has three components:
    • Class participation: volunteer to answer questions asked to the class
    • Class preparedness: you must have done the readings before coming to class
    • Involvement with the wiki: if you see an error, correct it; if you have a better explanation for something, change it; if you see something missing, add it
    • Get extra points by using Latex
• Homework: 60%
  • 6 assignments: 30%
    • 5% each, 1 week or less to complete
  • 3 projects: 30%
    • 10% each, 2 weeks to complete
  Homework rules
  • Due on Saturdays at 11:59pm Doha time. Submit on Blackboard
  • Graded by the following Sunday based on
    • rubric for programming components
    • rubric for essay components
  • To encourage good work and integrity, the instructor may invite students to his office to explain their solutions. Should this happen, the students' explanations will become part of their grades for that homework
  • No joint homework unless explicitly instructed
• Midterm exam: 10%, in class, closed books
• Final exam: 20%, 3 hours, closed books
• Bonus points: up to 10% for particularly elegant solutions
• Negative points: at least -100% if caught cheating
• Don't cheat!

Late Policy

Every student has up to 3 late days. You can use only one late day per assignment or project. No fractional late days: if you submit 1 minute late, you have used up a full late day. You should use late days for emergencies only: if you start early, you will not need them.

Academic Integrity

You are expected to comply with the University Policy on Academic Integrity and Plagiarism.

Collaboration is regulated by the whiteboard policy: you can bounce ideas about a homework with other students, but when it comes to typing it down for submission, you are on your own — no notes, files, snapshots, etc. Morever, you must wait at least 4 hours before writing down the solution.

Course Objectives

This course seeks to develop students who:

1. can leverage the mathematical structure of a problem to develop a solution
2. can use abstraction and modularity to manage complexity
3. can use formal arguments to justify the correctness of a problem solution and determine its asymptotic cost
4. master a non-declarative programming paradigm
5. have gained advanced skills, concepts and techniques in programming and Computer Science

Learning Outcomes

Upon successful completion of this course, students will be able to:

1. explain and use basic programming language concepts such as typing, evaluation, declarations, expressions, values, and types
2. explain and use advanced programming language concepts such as data types, pattern matching, polymorphism, higher-order functions, continuations, exceptions, streams, memoization, modularity
3. design recursive algorithms and develop recursive programs
4. use mathematical induction to prove program correctness
5. determine the asymptotic cost of a sequential and maximally parallel solution to a problem
6. model problems in Computer Science using lists, trees and graphs
7. exploit a problem's data flow to program parallel solutions
8. program symbolic solutions to problems using data types and pattern matching
9. use polymorphism and functional arguments to build reusable program modules
10. develop abstract and parametric modules for code reusability
11. recognize non-computable problems and give formal arguments to support non-computability claims

The course is organized around the following themes:

Weeks 1-5					Weeks 6-8			Weeks 9-14
Inductive definitions					Functions			Beyond induction and parallelism

In this course, there will be three types of class periods, one each week, in the following order:

• Problem solving lectures are listed below with a blue background. They will look at Computer Science problems from a mathematical perspective, emphasizing an abstract, logical, understanding of problems and solutions. You will rarely see a line of code in these lectures.
• Programming techniques lectures are listed with a green background. They serve two purposes: first they introduce some advanced, but language-independent, programming concepts (e.g., polymorphism and modularity); second they expose you to a functional programming language, Standard ML. Here, we will use the abstract problem solving techniques you have learned in the blue lectures and the advanced programming concepts to solve real problems.
• Lab sessions are listed with a gray background. Labs have the purpose of reinforcing the notions introduced earlier that week. You will be given a series of ungraded practice exercises that you will solve in class using a combination of paper and computer. The instructor and TA will be there to provide assistance. If you are done early you can either leave, or ask for additional exercises. Lab attendance is mandatory.