@@ -30,9 +30,12 @@ public static void main(String[] args)
 
 			if(program != null)
 			{
-				//Visit the tree starting at root (program)
-				Visitor v = new PrettyPrintVisitor();
-				v.visit(program);
+				if(parser.errorDetected == false)
+				{
+					//Visit the tree starting at root (program)
+					Visitor v = new PrettyPrintVisitor();
+					v.visit(program);
+				}
 			}
 			else
 			{
 
@@ -11,7 +11,12 @@ import visitor.*;
 /* Preliminaries to use the scanner. */
 scan with {: return lexer.next_token(); :};
 parser code {: Lexer lexer;
-public Parser(Lexer lex) { super(lex); lexer = lex; } :}; 
+boolean errorDetected;
+public Parser(Lexer lex) { super(lex); lexer = lex; errorDetected = false; }
+public void syntax_error(Symbol cur_token) { 
+				errorDetected = true;
+				System.err.println("Parse error at line " + cur_token.left + ", column " + cur_token.right); }
+ :}; 
 
 /* Terminals */
 terminal PERIOD, COMMA, SEMICOLON, LEFTCURLY, RIGHTCURLY, LEFTPAREN, RIGHTPAREN, LEFTBRACKET, RIGHTBRACKET;
@@ -173,7 +178,11 @@ statement ::= LEFTCURLY statementChain:sc RIGHTCURLY
 			  {: RESULT = new Assign(id, e1); :}
 			  |
 			  identifier:id LEFTBRACKET expression:e1 RIGHTBRACKET ASSIGNMENT expression:e2 SEMICOLON
-			  {: RESULT = new ArrayAssign(id, e1, e2); :};
+			  {: RESULT = new ArrayAssign(id, e1, e2); :}
+			  |
+			  error SEMICOLON:s
+			  {: :}
+			  ;
 
 statementChain ::= statement:stmt statementChain:sc
 				   {: if(sc == null)
Original file line number	Diff line number	Diff line change
`@@ -30,9 +30,12 @@ public static void main(String[] args)`
`30`	`30`
`31`	`31`	`if(program != null)`
`32`	`32`	`{`
`33`		`- //Visit the tree starting at root (program)`
`34`		`- Visitor v = new PrettyPrintVisitor();`
`35`		`- v.visit(program);`
	`33`	`+ if(parser.errorDetected == false)`
	`34`	`+ {`
	`35`	`+ //Visit the tree starting at root (program)`
	`36`	`+ Visitor v = new PrettyPrintVisitor();`
	`37`	`+ v.visit(program);`
	`38`	`+ }`
`36`	`39`	`}`
`37`	`40`	`else`
`38`	`41`	`{`