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

[Terence Parr]

Hi Soren :)  Heh, it's weird. i get no error when i run your grammar with 

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

could it be a weird char in your file?
Ter
On Feb 3, 2010, at 5:16 AM, Søren Andersen wrote:

> 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
> 
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