Programming Languages and Compilers COMP3131/COMP9102 26T1

List.java and LayoutVisitor.java

Posted by Jingling Xue Friday 06 March 2026, 02:46:06 PM.

If you haven't downloaed the starter code for Assignment 3, you can disregard this message.

If ASTs package includes List.java . This file is not used this year , so please delete it.

In addition, please comment out the visitS() method in VC/TreeDrawer/LayoutVisitor.java , as it is included for teaching purposes only .

// for lecture 7 only 
// public Object visitS(S ast, Object obj) { 
//   return layoutUnary("S", ast.E); 
// }

ASTs

Posted by Jingling Xue Friday 06 March 2026, 01:44:19 PM.

Dear COMP3131/9102 Students,

If you haven't downloaded ASTs.zip, please disregard this message. Otherwise, delete List.java from VC/ASTs, as it will not be used this year.

Assignment 3 Spec Released

Posted by Jingling Xue Wednesday 04 March 2026, 11:02:00 AM.

Dear COMP3131/9102 Students,

I have just released the specification for Assignment 3 (due on 18 March), a few days before Assignment 2 is due. There is some overlap between the two, as they are both part of the same overall assignment. Once you have implemented a parser in Assignment 3, the recogniser developed in Assignment 2 will no longer be used in future assignments. For this reason, no reference solution will be provided for Assignment 2.

In today’s lecture, I will cover how to write a parser for VC.

LL(k): Slide 217 from today's lecture (Mon 2 March)

Posted by Jingling Xue Monday 02 March 2026, 10:02:50 PM, last modified Tuesday 03 March 2026, 09:47:27 AM.

Dear COMP3131/9102 Students,

I have updated the last bullet point on Slide 217. Since you will have the opportunity to develop a top-down LL(1) parser, you are expected to have a general understanding of LL(k) grammars, at least for LL(1) and LL(2).

See the updated slide below: