Parser Project

Implementing the Tea Grammar using JavaCC

10 Points

Although you wrote a grammar for assignment #1, we'd like you to use our grammar for uniformity. If you think changes need to be made to our grammar, please post your concerns.

(a) Write JavaCC code to create a parser for this subset of Tea . Add print statements after each production to print out the name of the nonterminal on the left-hand-side of the production.

(b) Run it on the assigned programs from the lexer assignment and a program of your choice.

(c) Using the printed output, create a parse tree outline by hand. (In the next assignment, we'll create internal abstract syntax trees.) If you have a lot of nodes for your example, you need not draw every node.

The following is a subset of the solution to this project: 

 
 options {
   IGNORE_CASE = false;
   OPTIMIZE_TOKEN_MANAGER = true;
 }
 
 PARSER_BEGIN(tea)
 
 import java.io.*;
 
 public class tea {
 
   public static void main(String[] args) throws ParseException,
 						FileNotFoundException
   {
    if ( args.length < 1 ) {
       System.out.println("Please pass in the filename for a parameter.");
       System.exit(1);
    }
 
    tea parser = new tea( new FileInputStream(args[0]) );
 
    parser.program();
    System.out.println("Parse completed.");
   }
 }
 
 PARSER_END(tea)
 
 SKIP: /* Whitespace */
 {
   "\t"
 | "\n"
 | "\r"
 | " "
 }
 
 TOKEN: /* Most tokens */ 
 {
   <IF: "if">
 | <ELSE: "else">
 | <TYPE: "void">
 
 .....
 
 TOKEN: /* Generic Name & Number */
 {
   <NUMBER: (["0"-"9"])+>
 | <NAME: ["a"-"z","A"-"Z"] (["a"-"z","A"-"Z","0"-"9","_"])*>
 }
 
 void program() :
 {}
 {
   method_declaration() <EOF>
 }
 
 void method_declaration() :
 {}
 {
   <TYPE> <NAME> <LPAREN> <RPAREN> <LBRACE> statement_block() <RBRACE>
    { System.out.println("method_declaration"); }
 }
 
 void statement_block() :
 {}
 {
   ( statement() )*
 }
 
 void statement() :
 {}
 {
   simplestatement() <SEMICOLON> 
 | compoundstatement() 
 | <LBRACE> statement_block() <RBRACE>
    { System.out.println("statement"); }
 }
 
 void assignmentstatement() :
 {}
 {
   <NAME> [<ASSIGNOP> expression()]
    { System.out.println("Assignment Statement"); }
 }
  ...
Pass in: