Stephen A. Edwards Columbia University Crown
COMS W4115
Programming Languages and Translators
Fall 2021


Class meets Fridays 1:10 - 3:40 PM 717 Hamilton.


Name Email Office hours Location
Prof. Stephen A. Edwards
Max Levatich Th 5:30 - 7:30 PM Mudd 122 TA Room
John Hui T 9:30 AM - 11:30 AM Mudd 122 TA Room
Hao Zhou T 4:30 PM - 6:30 PM Mudd 122 TA Room


The goal of PLT is to teach you both about the structure of computer programming languages and the basics of implementing compilers for such languages.

The course will focus mostly on traditional imperative and object-oriented languages, but will also cover functional and logic programming, concurrency issues, and some aspects of scripting languages. Homework and tests will cover language issues. You will design and implement a language of your own design in a semester-long team project.

While few of you will ever implement a full commercial compiler professionally, the concepts, techniques, and tools you will learn have broad application.


COMS W3157 Advanced Programming: You will be dividing into teams to build a compiler, so you need to have some idea how to keep this under control. Quick test: you need to know about Makefiles and source code control systems.

COMS W3261 Computer Science Theory: You will need an understanding of formal languages and grammar to build the parser and lexical analyzer. Quick test: you must know about regular expressions, context-free grammars, and NFAs.


Date Lecture Notes Reading Due
Fri Sep 24 Intro. to Languages
Language Processors
Ch 1, 2
Ch. 2
Fri Oct 1 Some Outstanding Projects
Programming in OCaml

Fri Oct 8 "

Fri Oct 15 Syntax and Parsing
Ch. 3, 4
Fri Oct 22 "

Sun Oct 24 (no lecture; turn in homework)

HW1 .zip
Fri Oct 29 The MicroC Compiler
App. A
Sun Oct 31 LRM, Parser
Fri Nov 5 "

Fri Nov 12 Runtime Environments
Ch. 7
Hello World
Sun Nov 14 (no lecture; turn in homework)

pdf HW2
Fri Nov 19 "

Fri Nov 26 Thanksgiving Holiday
Fri Dec 3 Review for Final

Fri Dec 10 Final Exam
Wed Dec 22 Project Reports Due

Suggested Text

Alfred V. Aho, Monica Lam, Ravi Sethi, and Jeffrey D. Ullman.
Compilers: Principles, Techniques, and Tools.
Addison-Wesley, 2006. Second Edition.

The first edition was long the standard text on compilers; the second edition of the "dragon book" has now been updated and continues to be one of the more readable books on the topic. Columbia's own Prof. Al Aho is one of the authors.

Cover of the Dragon Book 2nd edition

Related Texts

Michael L. Scott.
Programming Language Pragmatics
Morgan Kaufmann, 2006. Second Edition.

A broad-minded book about languages in general, but has less on practical details of compiler construction.

Cover of Programming Language Pragmatics 2nd edition

Andrew W. Appel.
Modern Compiler Implementation in ML.
Cambridge University Press, 1998.

The opposite of Scott: focuses on compiler construction, not language design issues.
It uses the functional language ML, which is closely related to O'Caml, but just different enough to be annoying.

Cover of Appel

Lawrence C. Paulson
ML for the Working Programmer.
Cambridge University Press, 1996. Second edition.

A book about functional programming. It's written for the ML language, not O'Caml, but the two are closely related.

Cover of Paulson

Steven S. Muchnick
Advanced Compiler Design and Implementation.
Morgan Kaufmann, 1997.

A very extensive book on many aspects of compiler design. Starts about halfway through Appel and goes much farther. Recommended for serious compiler hackers only.

Cover of Muchnick

Objective Caml Resources

webpage The Caml Language Homepage. Compiler downloads and documentation. Start here.
webpage The Objective Caml System. Documentation and User's Manual for the whole system, including documentation for ocamllex, ocamlyacc, ocamldep, ocamldebug, and all the standard libraries.
webpage OCaml books, many available for free online
.tar.gz file OCaml source for the four-function calculator.
.tar.gz file OCaml source and test cases for the MicroC language, which generates LLVM IR.

The Project

The focus of 4115 is the design and implementation of a little language. You will divide into teams and design the goals, syntax, and semantics of your language, and implement a compiler for your language.

Final Report Outline

This is a critical part of the project and will be a substantial fraction of the grade.

Include the following sections:

  1. Introduction
  2. Language Tutorial
  3. Language Manual
  4. Project Plan
  5. Architectural Design
  6. Test Plan
  7. Lessons Learned
  8. Appendix

Project Resources

pdf An excellent final report: the Funk language by 4115 students Naser AlDuaij, Senyao Du, Noura Farra, Yuan Kang, and Andrea Lottarini.
pdf An excellent final report: the Sheets language by 4115 students Benjamin Barg, Gabriel Blanco, Amelia Brunner, and Ruchir Khaitan.

Language Reference Manuals

pdf Dennis M. Ritchie, C Reference Manual
pdf Kernighan & Ritchie, The C Programming Language
pdf The C Language Reference Manual (SGI)
pdf Stroustrup, The C++ Programming Language
pdf The Java Language Specification
pdf The C# Language Specification


CTeX: Functional LaTeX Language (SE)
pdfProposal pdfLRM
Rachel Liu, Unal Yigit Ozulku, Weicheng Zhao, and Hu Zheng
DRRTY: HTML Generation Language (SE)
pdfProposal pdfLRM
Rania Alshafie, Dylan Bamirny, Richard Lopez, and Trinity Sazo
GVL: Graph Visualization Language (HZ)
pdfProposal pdfLRM
Yaxin Chen, Aster Wei, Jiawen Yan, and Minhe Zhang
JEo-MC: Fractal Language (HZ)
pdfProposal pdfLRM
Melody Hsu, Jeremy Lu, Emma Schwartz, and Connie Zhou
Kazm: Object-oriented Language (JH)
pdfProposal pdfLRM
Katie Kim, Molly McNutt, Aapeli Vuorinen, and Zhonglin Yang
MQL: Database Query Language (ML)
pdfProposal pdfLRM
Pitchapa Chantanapongvanij, Peihan Liu, Yiqu Liu, and Daisy Wang
MX: Matrix Language (ML)
pdfProposal pdfLRM
Mauricio Guerrero, Aaron Jackson, Wilderness Oberman, and Rashel Rojas
Marble: Matrix Language (ML)
pdfProposal pdfLRM
HUAXUAN GAO, Qiwen Luo, Yixin Pan, and Xindi Xu
Pocaml: Poor Man's OCaml (JH)
pdfProposal pdfLRM
Peter Choi, Yiming Fang, Yunlan Li, and Feitong Qiao
SMAP: Probabilistic Language (JH)
pdfProposal pdfLRM
Tushar Arora, Andrew Magid, SWAPNIL PALIWAL, and Emily Sillars
See++: Pixel Graphics Language (HZ)
pdfProposal pdfLRM
Jack LaVelle, Vishrut Tiwari, Adar Tulloch, and Winston Zhang
TENLab: Distributed Tensor-based Language (HZ)
pdfProposal pdfLRM
Senhong Liu, Xincheng Xie, Xiangrong Xu, and Songqing Ye
Vowel: Text Processing Language (ML)
pdfProposal pdfLRM
Aidai Beishekeeva, Lex Mengenhauser, Vikram Rajan, and Coby Simler
cstar: Systems Programming Language (JH)
pdfProposal pdfLRM
Shannon Jin, Ryan Lee, Khyber Sen, and Joanne Wang

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40 % Project
40 % Final
20 % Homework


You will collaborate with your own small team on the programming project, but you may not collaborate with others on homeworks. Teams may share ideas about the programming assignments, but not code. Any two teams found submitting similar code will receive zero credit for the whole assignment, and repeat offenses will be referred to the dean. See the Columbia CS department academic policies for more details.


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