[antlr-interest] Newbie: NoViableAltException

[Buck, Robert]

I have no clue what you just said below. So let me start from the
beginning...

All I want to do is define a simple recursive grammar for a set-tuple
syntax that has input streams like:

(tuple@{(attr1=value1),(attr2=value2)}={(nestedtuple1=value3),(nestedtup
le2=value4)})


tuple
	:	L_PAREN tuple_declaration EQUALS ( tuple_value | set )
R_PAREN
	;
set
	:	L_CURLY tuple ( COMMA tuple )*
	;
tuple_declaration
	:	tuple_key ( AT_SIGN set )? 
	;
tuple_key
	:	IDENT
	;
tuple_value
	:	( PCHAR )*
	;

Goal: I need to be able to extract the tuple key-names and the values.
If the value is complex (starts and ends with curly-braces), I need to
handle those differently by constructing references to child nodes in a
tree-structure of sorts. Sets are always on the right hand side.

So is this part correct, or not?


> -----Original Message-----
> From: antlr-interest-bounces at antlr.org 
> [mailto:antlr-interest-bounces at antlr.org] On Behalf Of Diehl, 
> Matthew J
> Sent: Tuesday, July 24, 2007 5:09 PM
> To: antlr-interest at antlr.org
> Subject: Re: [antlr-interest] Newbie: NoViableAltException
> 
> You're mixing your lexer and parser rules.  IDENT is eating 
> up all of the UNRESERVED whenever there's more than one, 
> PCHAR if there's only one.  Then you're saying that 'bar', 
> which is more than one UNRESERVED, so it is the token IDENT, 
> needs to be a bunch of PCHARs, but the PCHARs have already 
> been turned in to the token IDENT.

[snip...]