while0parser.jj

PARSER_BEGIN(While0Parser)

import java.io.*;

public class While0Parser
{
	/*
	http://www.fh-wedel.de/~si/seminare/ws07/Ausarbeitung/04.javacc/praxis.html
	http://www.engr.mun.ca/~theo/JavaCC-Tutorial/javacc-tutorial.pdf
	*/
	public static void main(String args[])
	{
		try
		{
			String file_name = "../while0/simple.while0";
			FileInputStream fis = new FileInputStream(file_name);
			//While0Parser parser = new While0Parser(System.in);
			While0Parser parser = new While0Parser(fis);
			parser.run();

			System.out.println("WHILE0 Programm ok.");
		}
		catch (Exception e)
		{
			System.out.println("WHILE0 Programm fehlerhaft.");
			System.out.println(e.toString());
		}
	}
}

PARSER_END(While0Parser)

TOKEN :
{
	< IN: "in" >
|	< OUT: "out">
|	< VAR: "var">
|	< ASSIGN: "=" >
|	< PLUS: "+" >
|	< ZERO: "0" >
|	< ONE: "1" >
|	< NE: "!=" >
|	< WHILE: "while" >
|	< DO: "do" >
|	< BEGIN: "begin" >
|	< END: "end" >
|	< SEMICOLON: ";" >
|	< COMMA: "," >
|	< LPAREN: "(" >
|	< RPAREN: ")" >
|	< IDENT: (["a"-"z","A"-"Z"] (["0"-"9"])?)+ >
}
SKIP :
{
	" " | "\t" | "\n" | "\r" | "\r\n"
}
void run() :
{}
{
	<IDENT> <LPAREN> var_in() <SEMICOLON> var_out() <RPAREN> <SEMICOLON>
	<VAR> <LPAREN> var_help() <RPAREN> <SEMICOLON>
	statement()
}
void var_in() :
{}
{
	<IN> <IDENT> (<COMMA> <IDENT>)*
}
void var_out() :
{}
{
	<OUT> <IDENT>
}
void var_help() :
{}
{
	(<IDENT> (<COMMA> <IDENT>)*)*
}
void statement() :
{}
{
	(assign_statement() | while_statement()) (<SEMICOLON> statement())?
}
void assign_statement() :
{}
{
	<IDENT> <ASSIGN> (<ZERO> | <IDENT> <PLUS> <ONE>)
}
void while_statement() :
{}
{
	<WHILE> <IDENT> <NE> <IDENT> <DO> <BEGIN> statement() <END>
}