/**********************************************************************
 CS 536 Java Cup Example:

 This is the main program to test the Java Cup example.  This main
 program is essentially the same as the P3.java file provided for you
 in Program 3.

 There should be 2 command-line arguments:
    1. the file to be parsed
    2. the output file into which the AST built by the parser should be
       unparsed
 The program opens the two files, creates a scanner and a parser, and
 calls the parser.  If the parse is successful, the AST is unparsed.
 **********************************************************************/
    
import java.io.*;
import java_cup.runtime.*;

public class JavaCupEx {
    public static void main(String[] args)
	throws IOException // may be thrown by the scanner
    {
	// check for command-line args
	if (args.length != 2) {
	    System.err.println("please supply name of file to be parsed and name of file for unparsed version.");
	    System.exit(-1);
	}

	// open input file
	FileReader inFile = null;
	try {
	    inFile = new FileReader(args[0]);
	} catch (FileNotFoundException ex) {
	    System.err.println("File " + args[0] + " not found.");
	    System.exit(-1);
	}

	// open output file
	PrintWriter outFile = null;
	try {
	    outFile = IO.openOutputFile(args[1]);
	} catch (IOException ex) {
	    System.err.println("File " + args[1] + " could not be opened.");
	    System.exit(-1);
	}

	parser P = new parser(new Yylex(inFile));

	Symbol root=null; // the parser will return a Symbol whose value
	                  // field's type is the type associated with the
	                  // root nonterminal (i.e., with the nonterminal
	                  // "program")

	try {
	    root = P.parse(); // do the parse
	    System.out.println ("Input parsed correctly.");
	} catch (Exception ex){
	    System.err.println("Exception occured during parse: " + ex);
	    System.exit(-1);
	}
	((ASTnode)root.value).unparse(outFile, 0);
	outFile.close();

	return;
    }
}