Homework 2
Lexical Analysis  

• Overview
• Assignment
• Files
• Getting Started
• Turn In
• Resources

Overview

The text examines two programs that generate Java lexical analyzers: JavaCC and SableCC. Examples from the text for each generator will be given with instructions on their use.

Assignment

Complete the lexical-analysis part of the JavaCC and SableCC specifications for MiniJava grammar; that is define the tokens for MiniJava. The tokens are bold-faced in the grammar of section A.2 along with the Lexical Issues described in section A.1 of the appendix. One simiplication we'll make is that /* */ comments cannot be nested.

For JavaCC do only those parts necessary for the Sample.java test program.

For SableCC do the complete MiniJava grammar.

• Appendix A of the text describes MiniJava syntax, which can be compiled by Java. The lexical part is the bold-face keywords, identifiers, integers, comments, binary operators and special characters (e.g. '{', '!', '.', etc.). For example, given the string "a=123;" the analysis would produce something similar to: <IDENTIFIER><EQUAL><INTEGER_LITERAL><SEMICOLON> in JavaCC while SableCC would echo back the characters of the tokens.
• Test using the sample program.

Files

Download the following files:

1. Program2.9.jj - JavaCC definitions from text p. 31. Note that this is not MiniJava but can serve as an example and starting point.
2. Program2.10.js - SableCC definitions from text p. 32. Note that this is not MiniJava but can serve as an example and starting point.
3. Main.java - Calls the SableCC lexical analyzer.
4. Lexical 1, 2, 3 - lexical test programs. Lexical1 and Lexical2 are correct for the definitions, Lexical3 has errors.
5. Sample.java - Sample MiniJava program.

Getting Started

• Home:
  • Download JavaCC and/or SableCC software and unzip to the root level directory.
  • Enter the following at the DOS Command window:

    path=%path%;\javacc-3.2\bin

  IUS:

  • Enter in the DOS Command window:

  v:\common\user\C431\CC
  v:\common\user\C311\forjava
   

• JavaCC
  1. Download Program2.9.jj and Lexical1.txt.
  2. Generates lexical analyzer named MyParser.java, assumes JavaCC is a root-level directory.

     JavaCC Program2.9.jj
      

  3. Compile all Java files in directory.

     javac -classpath . *.java
      

  4. Analyze the contents of file Lexical1.

     java -cp . MyParser < Lexical1.txt
      

• SableCC
  1. Download Program2.10.js and Lexical1.txt.
  2. To generate the SableCC lexical analyzer:

     Home:    java -jar \sablecc-2.18.2\lib\sablecc.jar Program2.10.js

     IUS:      java -jar v:\common\user\C431\sablecc.jar Program2.10.js
      

  3. Download Main.java to the sub-directory named Program2.
  4. To delete an older version of the analyzer and compile the Java program named Program2\Main.java enter:

     del Program2\Main.class

     javac -classpath . Program2\Main.java
      

  5. To perform the lexical analysis of Lexical1:

     java -cp . Program2.Main < Lexical1.txt

Turn In

1. Cover sheet with your name, C431, date, and Homework 2.
2. Print out of JavaCC and SableCC specification file for MiniJava.
3. Screen shot listing of Command prompt window showing generation and analysis of Sample.java program for JavaCC and SableCC.

Resources

SableCC

• tutorial
• documentation

JavaCC

• documentation