2110316  Programming Languages Principles 3(3-0-6)

1st semester  2016

Prabhas Chongstitvatana

official course description

Principal lecturer: Twittee.  This course is divided into three equal parts.  Three parts are taught by three different lecturers.

1) Programming Language concepts, Twittee
2) Non-imperative programming language, Nattee + Pitchaya 
3) Language and implementation, Prabhas

The goal of this course is to make you understand the 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 machine and understand trade-offs in programming language design.  

Each part will be taught separately and independently. It is logical that the assessment will also be arranged according to this structure. There is no midterm exam (besides whatever assess by the lecturer at that time) and the final exam will contain all materials taught in the course.

Assessment

each part  20%  by 3  = 60%
final exam                      40%

Language and implementation

This 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 homework and classwork. To teach effectively I choose to design a toy language and implement its compiler. There are two implementation, in C and in Javascript. You will be studying actual compilers and modify them.

old lecture  2012  2013   2014  2015

Announcement

8 Nov 2016   -- The class on 10 Nov is cancelled.  Please do the homework new 2.
15 Nov 2016  --  Quiz will be held on 17 Nov 2016, 10am at the classroom.
21 Nov 2016  --  Project is posted, it is due 4pm, Friday 2 December 2016
22 Nov 2016 --  IMPORTANT The part code generation will not be present in the final examination questions.

Study Plan

plan for 4 weeks, with one week to spare
each week has 2 sessions of 1 1/2 hrs. each.
a homework will be handed out each week.
one project will be issued on week 3.

workload

one small project
one in-class exam
weekly homework

Lecture sessions

1  structure of a compiler
       Intro to Compiler (ppt)  Supplement: Cross compiler (ppt)
       High Level Language  to  Low Level Language  to  Processor architecture
              Demonstrate the actual compiler of this course RZ.   Rz compiler on web
2  lexical analyser      Scanner (ppt)
--------------------------
3  grammar             
         Recursive programming with List    extra exercises
         Context Free Grammar  (ppt)   Example of writing a grammar to specify a language
4  parsing       Parsing (ppt)    top-down parsing   How to compute First and Follow set  (by Prof. Kamin at UIUC)
                      LL parser at Wiki         
----------------------------
5  actual parser   Example of writing  a recursive descent parser for a simple language
                           Example of a parser with building parse tree      
6  code generator        Code Generation     Som v2.0 virtual machine   S-code
    recursive evaluator    here is the source code in C for an interpreter of Rz parse tree    eval3.c
---------------------------
7  actual code generator  How to do code generation
    project announcement

Bonus:  Retro programming or the power of emulation 

Assessment for this part

one project       5%         
exam              15%   
total               20%

Classwork

  3 Nov 2016 -- 
       1. Write a grammar for this song

I'd like to build the world a home
And furnish it with love
Grow apple trees and honey bees
And snow white turtle doves

I'd like to teach the world to sing
In perfect harmony
I'd like to hold it in my arms
And keep it company

       2. Write a recursive program for 1) reverse complex list, 2) clone(L) (ex 3 in lecture recursive programming)

Homework

Old
1.  Learn how to write in Rz by reading  Quick Start Rz.
2.  Download and compiler the compiler used in this class (rz33-1.zip).  Use whatever compiler for C that you are familiar with and compile it. Try it out to compile some simple program.   For recommended free C compiler, see Tools section below.
3.  Try the example of ASM parser.  Change the ASM language a little bit, such as, make an op code to have three arguments (i.e.  add r1,r2,r3).  Then, change your CFG to reflex this.  Then, modify the parser to parse it.

New
1.  Try your hand on recursive programming.  Do ex 3 (clone)Do extra exercises.
2.  Practice Grammar writing.  Given the following sentences:
f(id)
f(f(id))
f(id,id)
f(f(id),id)
...  
    2.1  Write Grammar for this language.
    2.2  Write a recursive-descent parser followed from Grammar for this language. 
    2.3  Bonus:  in your parser, construct a parse-tree (see example "a parser with build parse tree")

Project

1) Write a report on how a compiler or an interpreter of a computer language works.  You have to choose from three languages: LISP, Python and Haskell (one from the past, one of the present and one in the future).  Choose the language you like most (or that has something that you find interesting).

I want the content to be focused on compiler (interpreter) rather than historical facts and other tidbits.  You must write in your own word (in Thai or in English). Do not cut and paste. You need to synthesize your idea. The length of the report is around 4 pages.  I expect this to take you about 9 hours of work. 

Hand in your report in paper.  Put it in the inbox in front of my office before 4pm, Friday 28 Oct 2016.  Late submission will not be accepted.

Here is some link for you to start (You don't have to use these sources.  You can find whatever you like)
LISP  compiler and interpreter
Python  is it an interpreter?    PyPy
Haskell   introduction   from the real source   inline (heavy reading!)

New

Write a parser --  Given a language, write its grammar, computer its First and Follow set, make the parsing table. Then, write its parser. You must hand-in a report of length 4-5 pages contains the following:

1)  Grammar, First and Follow set, parsing table
2)  Pseudo code of your parser
3)  Examples that show that your parser work

You don't need to send me the actual code for the parser. 

Please hand-in your report before 4 pm, Friday 2 December 2016, at the box in front of my office, building 4, floor 18, room 13. Late submission will not be accepted.

The language :

------------------------------------

A language that "verbalise" programming.  Imagine how to help a blind person to write a computer program.  We can use speech recognition to "transcribe" sound to text.  However it is cumbersome to just spell out text of our conventional programing language.  Try to read this "hello world" aloud.

#include <stdio.h>

int main(void){
  printf("hello world\n");
  return 0;
}


Let us improve the "verbalisation" a little bit.  We can use "command" then follow by "parameters".  When the number of parameters is variable, we can use the word "stop" to delimit them. We can also use that to say the end of the code block.  Let us use this example:

square(x){
  return x * x;
}


We can verbalise it like this:

function square parameter x stop block return expression x mul x stop

Wow, this will be super good!
---------------------------------------

Now, back to your project,  use this idea to design your small language (you can use the above example, it is good enough to be used to write a simple program with no data type).  Give examples of your program, both input "speech" and output (C like).  Write the grammar for your language.  Implement a parser (no need to generate output), a pure parser that parses proper input is sufficient.

Hope you enjoy this project.  If you want any discussion, please use Courseville of this class, or failing that Facebook messenger to me, find me "Prabhas Chongstitvatana".  I promise to check the channel once a day. 

Reference 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 first one is the standard text book 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.   The second one (Louden) is much easier to read.  I will update some chapter from my textbook from time to time as necessary. 1997 is the latest edition, you can find it in Amazon.

Extra reading

Tools

See my Rz language homepage
the compiler  package with code generator for s-code  rz33-1.zip 
Zero Assembler   source, example and executable (including som v2 vm) ( zas.zip )
Rz compiler on the web  (by Kamoluk Suksen)
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). 
Example of building parse tree   ex-parse-tree.zip

How to use the compiler

Use rz33-1.zip  to compile and run your programs.   Here is what a session looks like.  Go to rz33/test directory  (that you unzip the package to).  There are two executable files:   rz33.exe  and  somv2x.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:\prabhas\bag\rz\rz33\test>rz33 fac.txt
fac
main
(fun main (print (call fac 6 )))
(fun fac (else (== #1 0 )(return 1 )(return (* #1 (call fac (- #1 1 ))))))

:main
    fun.1
    lit.6
    call.fac
    sys.1
    ret.1
:fac
    fun.1
    get.1
    lit.0
    ...

   
You will get the file "fac.obj" as an output file.  It is an object file that is executable under Som VM (a kind of virtual machine similar to JVM). You can "run" it under somv2x.

D:\prabhas\bag\rz\rz33\test>somv2x fac.obj
720


That's it.  Enjoy!

Prabhas Chongstitvatana
contact address:   prabhas at chula dot ac dot th     
office   room 18-13  Engineering Building 4, floor 18.  tel 02-2186982
research lab:  Intelligent Systems,  floor 20.

Last update  22 Nov 2016