Computer Languages and Implementations

Jan-Apr 2026

Prabhas Chongstitvatana

The goal of this course is to make you understand computer languages you use. To make you appreciate diversity of ideas in programming and prepare you for new programming methods and paradigms. Theoretical foundations will be presented. You will know properties of language, not just syntax. Moreover, you will recognize the cost of presenting an abstract view of machines and understand trade-offs in programming language design.

The second part concerns a compiler for a programming language. There are two aspects of learning this part: theory and practice. The theory will be given in the lectures. The practice is carried on as classwork. To teach effectively I choose to design a toy language and implement its compiler. You will be studying actual compilers and modify them.

Assessment

. . .

Announcement

. . .

Lectures

Language Implementations

1 structure of a compiler

Intro to Compiler Supplement: Cross compiler
lexical analyser Scanner

2 grammar

Demonstrate the actual compiler of this course

Context Free Grammar

Example of writing a grammar to specify a language

Recursive programming with List extra exercises

3 parsing

Parsing top-down parsing
How to compute First and Follow set (by Prof. Kamin at UIUC)

LL parser at Wiki

4 actual parser
        a recursive descent parser for a simple language
        a parser with building parse tree
        write a parser from a parsing table
        LL1 parser of grammar from lecture parsing page 25 (LL1-parser.zip) (slide)

5 code generator

        Code Generation Som v2.0 virtual machine   S-code
        Recursive evaluator, an interpreter of Rz parse tree    eval3.c
        Code generation pptx

6 bottom up parser

Bottom Up parsing pptx

Theory of programming language

        Introduction
        Names, scope and binding
        Functional programming language

Runtime support for imperative language (from: https://www.rose-hulman.edu/class/csse/csse404/schedule/day17/Procedures.pdf)

Runtime support for functional language

Lambda function

closure from Wiki

Garbage collection

Videos

Compiler, Grammar, Context Free Grammar
https://youtu.be/6jOBVCbNw8w?si=lIMDJsK0QedJjAdy

Parsing 1
https://youtu.be/O_nMvMUEFkw?si=d5EFon8rcXvZqy8m

Parsing 2
https://youtu.be/tEy7ZfpKZt0?si=T3aNS6365GiMfWzE

Runtime support for Imperative language https://youtu.be/eBH_yTDjk7Y

Activation record: Demo code and data https://youtu.be/xhAh2bpFLJs

Garbage collection https://youtu.be/vhTpUz3W4LQ

Reference Text

-- Jaruloj Chongstitvatana, Programming Languages Principles and Processing, (local copy) Dept. of Math and CS, Chulalongkorn, 2017. (main text)
-- Aho, Sethi, Ullman, Compilers: Principles, Techniques, and Tools. Addison-Wesley, latest edition.
-- Louden, K.C., Compiler Construction: Principles and Practice. PWS Publishing Co., 1997.

The main text is Jaruloj. It covers larger topics than required in this class. Our presentation follows this textbook. Aho,Sethi, Ullman is the standard textbook on compiler. It has been used in more than 100 universities in North America. It is a bit difficult to read as it contains a lot of theory. Louden is much easier to read. The latest edition is 1997, you can find it at Amazon.

Extra reading

A chart of genealogy of programming languages (pdf) (You need to zoom to 100% to see it)

Tools

Recommended free C compiler for Windows lcc-win32 . (for Windows 7, 8, 8.1 and 10). Please also download and install "User Manual". You need it to look up the library function of this C. (for OS X you need xcode, also free).

See my Rz language homepage

the compiler package with code generator rz36-3.zip

lexical analyser (lex-35-3.zip, extract from rz35-3 package)

Rz compiler on the web (by Kamonluk Suksen)

Example of a recursive descent parser for a simple assembly language asm-parser-2.zip
LL1 parser from lecture parsing page 25 LL1-parser-2.zip works on both Windows 10 and MacOS (I use xcode to compile on Mac). The executable file for Mac is used this way, on Mac opens a terminal:

$
          ./xparser test.txt

To practice recursive programming in the lecture, you need this library ailib2.zip (in C).
Example of building parse tree ex-parse-tree-2.zip

How to use the compiler

Use rz36 to compile and run your programs. Here is what a session looks like. Go to rz36/test directory (that you unzip the package to). There are three executable files: rz36.exe, as21.exe, sim21.exe . Try to compile "fac.txt". It is shown here:

// factorial

 fac(n)

          if( n == 0 ) return 1

          else return n * fac(n-1)


        

        main()

            print(fac(6))

Here is the command line and the output at the screen:

D:\rz36\test>rz36
          fac.txt

          fac

          main

          (fun main (print (call fac 6 )))

          (fun fac (else (== #1 0 )(return 1 )(return (* #1 (call fac (- #1 1
          ))))))

        

        

            ...

You will get the assembly file as an output file. Then, use as21.exe to "assemble" (change assembly file into object code file). You can "run" it under s2 simulator (execute machine code) s21.exe.

D:\rz36\test>sim21
          fac.obj

          720

That's it. Enjoy!

Prabhas Chongstitvatana
contact address: prabhas dot c at chula dot ac dot th
office room 18-13 Engineering Building 4, floor 18.

Last update 25 December 2025