[antlr-interest] Problem "debugging" ANTLR error messages.

[Søren Andersen]

Hello,

I'm new on this mailing list, so be nice :)

I'm toying with a Java-like language for fun, and I'm having a problem with ANTLR crashing when trying to use it.

Consider the following grammar:

grammar test;

ID  :	('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*
    ;

INT :	'0'..'9'+
    ;

NEWLINE :	'\r'? '\n';

class_decl 
	: 'class' name '{' NEWLINE* method* '}';
method 	:	type name '(' formalArgs? ')' NEWLINE* '{' NEWLINE+ stmt* '}' NEWLINE* ;
formalArgs
	:	type name (',' type name)*;
type 	:	ID NEWLINE*;
name	:	ID NEWLINE*;

stmt 	:	variable_decl ';' NEWLINE* | method_call ';' NEWLINE*;

assignment 
	:	name '=' expression;
variable_decl
	:	type name '=' expression;
	
creation 	
	:	'new' name '(' arglist? ')' NEWLINE*;
method_call 
	:	recievers name '(' arglist? ')' NEWLINE*;
arglist :	expression (',' expression)*;
recievers 
	:	(name '.')* | '(' creation ')' '.' (name '.')* ;
expression
	:	method_call | creation | name;

This works perfectly, and as expected!
However, change the stmt rule to:

stmt 	:	variable_decl ';' NEWLINE* | method_call ';' NEWLINE* | assignment ';' NEWLINE*;

And suddenly ANTLR says:

[14:14:32] error(10):  internal error: Exception test.g:19:64: unexpected char: 0xA0 at org.antlr.grammar.v2.ANTLRLexer.nextToken(ANTLRLexer.java:347): unexpected stream error from parsing test.g 

[14:14:32] error(150):  grammar file test.g has no rules
[14:14:32] error(100): test.g:0:0: syntax error: assign.types: <AST>:0:0: unexpected end of subtree
[14:14:32] error(100): test.g:0:0: syntax error: define: <AST>:0:0: unexpected end of subtree

I'm having a hard time figuring out why... Any tips? I mean - had the grammar become ambiguous or something, I'd understand - but this looks like ANTLR is crashing?
I'm using ANTLRworks 1.3.1.

Regards,

Søren