compiler.java

java compiler project to implement LR parsing

/*******************************************************************************
 * Compiler. 
 * New language which is called BASCAL.
 * Date : 20/9/2006,Time : 2:41.
 ******************************************************************************/
package mk.ceit; 

import java.util.StringTokenizer;
import java.util.Scanner;
import java.io.*;
import javax.swing.JOptionPane;

public class Compiler
{
	private Scanner scan;
	private StringTokenizer token;
	private StringTokenizer temp;
	private String code,tokens,error="",details="";
	private int counter=0;
	private Token t;
	private int numberOfErrors=0;
	
	/**************************************************************************/
	/**The following constructor is used for sent the text of code into it.
	/**************************************************************************/
	public Compiler(String code)
	{
		this.code=code;
		start();
		newLine();
	}
	/**************************************************************************/
	/**The following constructor is used for sent the file of code into it.
	/**************************************************************************/
	public Compiler(File fileName)throws IOException
	{
		code="";
        Scanner scanner=new Scanner(fileName);
		while(scanner.hasNextLine())
		{
			code+=scanner.nextLine()+"\n";
		}
		start();
		newLine();
	}
	/**************************************************************************/
	public void compile()
	{
		match("program","KeyWord");
		match("","Identifier");
		match(";","KeyWord");
		declarations();
		subprogram_declarations();
		compound_statement();
		match(".","KeyWord");
	}
	/**************************************************************************/
	private void declarations()
	{
		if(t.getTokenName().equalsIgnoreCase("var"))
		{
			match("var","KeyWord");
			identifier_list();
			match(":","KeyWord");
			type();
			match(";","KeyWord");
			declarations();
		}
		else{}
	}
	/**************************************************************************/
	private void identifier_list()
	{
		match("","Identifier");
		identifier_list2();
	}
	/**************************************************************************/
	private void identifier_list2()
	{
		if(t.getTokenName().equals(","))
		{
			match("," ,"KeyWord");
			match(""  ,"Identifier");
			identifier_list2();
		}
		else{}
	}
	/**************************************************************************/
	private void type()
	{
		if(t.getTokenName().equalsIgnoreCase("array"))
		{
			match("array","KeyWord");
			match("["    ,"KeyWord");
			match(""     ,"Numeric");
			match(".."   ,"KeyWord");
			match(""     ,"Numeric");
			match("]"    ,"KeyWord");
			match("of"   ,"KeyWord");
			standard_type();
		}
		else
		standard_type();	
	}
	/**************************************************************************/
	private void standard_type()
	{
		if(t.getTokenName().equalsIgnoreCase("integer")
		||t.getTokenName().equalsIgnoreCase("real"))
		match(t.getTokenName(),"KeyWord");
	}
	/**************************************************************************/
	private void subprogram_declarations()
	{
		if(!t.getTokenName().equalsIgnoreCase("function")&&
	    !t.getTokenName().equalsIgnoreCase("procedure"))
	    {}
	    else
	    {
	    	subprogram_declaration();
	    	match(";","KeyWord");
	    	subprogram_declarations();
	    }
	}
	/**************************************************************************/
	private void subprogram_declaration()
	{
		subprogram_head();
		declarations();
		compound_statement();
	}
	/**************************************************************************/
	private void subprogram_head()
	{
		if(t.getTokenName().equalsIgnoreCase("function"))
		{
			match("function","KeyWord");
			match(""  ,"Identifier");
			arguments();
			match(":","KeyWord");
			standard_type();
			match(";","KeyWord");
		}
		else
		if(t.getTokenName().equalsIgnoreCase("procedure"))
		{
			match("procedure","KeyWord");
			match(""  ,"Identifier");
			arguments();
			match(";","KeyWord");
		}
	}
	/**************************************************************************/
    private void arguments()
    {
    	if(t.getTokenName().equals("("))
    	{
    		match("(","KeyWord");
    		parameter_list();
    		match(")","KeyWord");
    	}
    	else
    	{}
    }
    /**************************************************************************/
    private void parameter_list()
    {
    	identifier_list();
    	match(":","KeyWord");
    	type();
    	parameter_list2();
    }
	/**************************************************************************/
	private void parameter_list2()
    {
    	if(t.getTokenName().equals(";"))
    	{
    		match(";","KeyWord");
	    	identifier_list();
	    	match(":","KeyWord");
	    	type();
		 	parameter_list2();
    	}
    	else
    	{}	 	
    }
    /**************************************************************************/
	private void compound_statement()
	{
		match("begin","KeyWord");
		optional_statements();
		match("end","KeyWord");
	}
	/**************************************************************************/
	private void optional_statements()
	{
		
		if(!t.getTokenName().equalsIgnoreCase("end"))
 		if(!t.getTokenName().equalsIgnoreCase("begin")&&
 		   !t.getTokenName().equalsIgnoreCase("if")&&
 		   !t.getTokenName().equalsIgnoreCase("while")&&
 		  (!t.getTokenName().matches("[a-zA-Z]\\w*")&&
 		   !isKeyWord(t.getTokenName())))
 		{}
 		else
 		statement_list();
	}
	/**************************************************************************/
	private void statement_list()
	{
		statement();
		statement_list2();
	}
	/**************************************************************************/
	private void statement()
	{
		if(t.getTokenName().equalsIgnoreCase("if"))
		{
			match("if","KeyWord");
			expression();
			match("then","KeyWord");
			statement();
			match("else","KeyWord");
			statement();
		}
		else
		if(t.getTokenName().equalsIgnoreCase("while"))
		{
			match("while","KeyWord");
			expression();
			match("do","KeyWord");
			statement();
		}
		else
		if(t.getTokenName().equalsIgnoreCase("begin"))
		{
			compound_statement();
		}
		else
		if(t.getTokenName().matches("[a-zA-Z]\\w*"))
		{
			match("","Identifier");
			statement2();
		}
	}
	/**************************************************************************/
	private void statement_list2()
	{
 		if(t.getTokenName().equals(";"))
 		{
 			match(";","KeyWord");
 			statement();
 			statement_list2();
 		}
 		else
 		{}
	}
	/**************************************************************************/
	private void statement2()
	{
		if(t.getTokenName().equals(":="))
		{
			match(":=","KeyWord");
			expression();
		}
		else
		if(t.getTokenName().equals("["))
		{
			match("[","KeyWord");
			expression();
			match("]","KeyWord");
			match(":=","KeyWord");
			expression();
		}
		else
 		if(t.getTokenName().equals("("))
 		{
 			match("(","KeyWord");
 			expression_list();
 			match(")","KeyWord");
 		}
 		else
 		{}
	}
	/**************************************************************************/
	private void expression()
	{
		simple_expression();
		expression2();
	}
	/**************************************************************************/
	private void expression2()
	{
		
 		if(t.getTokenName().equals(":=")||t.getTokenName().equals(">")||
 		t.getTokenName().equals("<")||t.getTokenName().equals(">=")||
 		t.getTokenName().equals("<=")||t.getTokenName().equals("<>"))
 		{
 			match(t.getTokenName(),"KeyWord");
 			simple_expression();
 		}
 		else
 		{}
	}
	/**************************************************************************/
	private void expression_list()
	{
		expression();
		expression_list2();
	}
	/**************************************************************************/
	private void expression_list2()
	{
 		if(t.getTokenName().equals(","))
 		{
 			match(",","KeyWord");
 			expression();
 			expression_list2();
 		}
 		else
 		{}
	}
	/**************************************************************************/
	private void simple_expression()
	{
 		if(t.getTokenName().equals("-")||t.getTokenName().equals("+"))
 		{
 			match(t.getTokenName(),"KeyWord");
 			term();
 			simple_expression2();
 		}
 		else
 		{term();simple_expression2();}
	}
	/**************************************************************************/
	private void simple_expression2()
	{
 		if(t.getTokenName().equals("-")||t.getTokenName().equals("+")||
 		t.getTokenName().equalsIgnoreCase("or"))
 		{
 			match(t.getTokenName(),"KeyWord");
 			addop();
 			term();
 			simple_expression2();
 		}
 		else
 		{}
	}
	/**************************************************************************/
	private void sign()
	{
 		if(t.getTokenName().equals("-")||
 		t.getTokenName().equals("+"))
 		{
 			match(t.getTokenName(),"KeyWord");
 		}
	}
	/**************************************************************************/
	private void addop()
	{
 		if(t.getTokenName().equals("-")||
 		t.getTokenName().equals("+")||