CPS710	Assignment 1
	Scanner	Due: October 2

Objectives

In this assignment you will be using JavaCC to build HL's scanner. This should familiarize you with the use of lexer generators and the scanning process.

The learning objectives addressed in this assignment are 2Cc (which includes 2De), 2Ba, and 2Aa.

Preparation

Here is how you should prepare your environment on the moons:

1. Create a directory where you will do your work, with a subdirectory called Tests.

2. Copy all the files in the Handouts directory into your working directory. These files are located on the moons at ~cps710/public_html/doc/F2024/A1/Handouts and you can copy them into your current directory with the command:

   cp ~cps710/public_html/doc/F2024/A1/Handouts/* .
   cp ~cps710/public_html/doc/F2024/A1/Handouts/src/* .
   

   Here are the files:

   • A skeleton version of HL.jj that you can start your work with.

   • Two files containing the main program for your assignment, which is in the class TestHL. This program is a fairly standard main program to test javacc scanners. Do not modify the contents of these files as we will be using the posted ones to test and grade your scanner. Both files define the TestHL class:
     • TestHLC.java is for testing learning objective C only. This file works properly when STRING tokens, which are in the B learning objectives, are not yet implemented.
     • TestHLB.java is for testing all learning objectives. It includes special code for STRING tokens.
     • There is a third file, TestHL.java but it is just a copy of TestHLC.java which is the one that you will need at the beginning of the assignment before you start implementing strings.

   • The makefile that will be used to compile your program on the moons. This is a minimal make file for the C learning objective. It will need to be modified to support the additional files needed for the B learning objective. You can learn about the make program by typing "man make" on the moons or from the GNU Make Manual.

   • Two testing scripts, t and runtests. They will be described in the Testing section below.

3. Make the two testing scripts t and runtests executable by giving them user x perms. This is done with the command:

   chmod u+x t runtests

4. Get rid of the two TestHL source files that you will not need at first (you will be left with TestHL.java which is a copy of TestHLC.java):

   rm TestHLC.java
   rm TestHLB.java
   

5. Compile everything once to make sure that your compilation settings are correct. This is done with the command:

   make

   This will also generate additional files that you can modify later.

6. Test that your program is running properly by typing

   java -classpath . TestHL

   and typing the strings "else" and "for".

Assignment

If you are planning to implement the B learning objectives in this assignment, then you will need to replace TestHL.java by TestHLB.java after you have implemented STRING tokens:

cp ~cps710/public_html/doc/F2024/A1/Handouts/src/TestHLB.java ./TestHL.java

Testing your Assignment

The testing files used to test your submissions are in the Tests directory. If you are doing your testing only on the moons, you do not need to copy these files because the test scripts access them directly. However, if you need to copy them for any reason, the direct path on the moons of the Tests directory where you can retrieve them from is ~cps710/public_html/doc/F2024/A1/Tests

The test files have prefixes describing the learning objective tested. Some learning objectives are tested with multiple files. You can see the order in which the tests are run in runtests.

Each test consists of two files, an .hl file for the input, and a corresponding .expected file for the expected output against which your output will be compared using the testing scripts:

• runtests runs all the tests for all learning objectives one by one using the t script. If your submission only deals with the C learning objective, then you should remove the tests for the B and A learning objectives when you do your own testing.

• t is a script for running one test file. As you can see in runtests, and in t itself, t takes one parameter ($1) which is the name of the test. It
  1. runs your program on that test. (Your java program files are assumed to be in the same directory as t and runtests)
  2. creates an output file for that test with a .out extension in the Tests subdirectory of your working directory
  3. compares your output file with the expected output.
  When your submission passes a test, all that will be printed is the test name. Otherwise you will see the diff of your .out file with the .expected file for that test.

Submitting your Assignment

Once you have verified that your source does compile and run properly on the moons:

If you are submitting work for the C learning objective only:

1. zip up your HL.jj file into a file called A1C.zip
   You can do this on the moons, by simply typing

     zip A1C HL.jj 
   

2. Submit electronically on the moons A1C.zip
   Simply put, you can do this on the moons by typing

     submit-cps710 A1C.zip
   

Otherwise: (we will run all B and A tests):

1. zip up your HL.jj, Token.java, NumberToken.java, IdNumToken.java, IdSetToken.java, IdBoolToken.java and StringToken.java files into a file called A1A.zip
   You can do this on the moons, by simply typing

     zip A1A HL.jj Token.java NumberToken.java Id*Token.java StringToken.java
   

2. Submit electronically on the moons A1A.zip
   Simply put, you can do this on the moons by typing

     submit-cps710 A1A.zip
   

References

CPS710 Material

• Class Example
• Class Handout on JavaCC

Explanations

The following provide overviews of scanning with Javacc and are good places to get started because they have enough information to help you produce a very basic JavaCC file that detects the simple tokens and skips whitespace.
• Main JavaCC site provides an overview of JavaCC.
• JavaCC [tm]: TokenManager MiniTutorial gives a good overview of how JavaCC handles tokens and how to write a JavaCC program.
• Wikibooks' Compiler Construction also gives a good overview: read the Lexical Analysis section. The comment section will get you properly started with comments.
• Chapter 2 of the JavaCC textbook by Tom Copeland are quite thorough.

Specific References

• JavaCC Documentation including the JavaCC [tm]: API Routines which contains a comprehensive list of all classes, methods, and variables available for use by a JavaCC user.
• The JavaCC FAQ
• See course references for further JavaCC references.