[antlr-interest] Decision can match input such as ... using multiple alternatives

[Andrey Pavlenko]

Hi All,
Could someone help me with the below grammar? I'm getting the
following warning on the 'attr_value : ~(EOL | '#' | '[' | ']')+;'
rule:
warning(200): config.g:33:4: Decision can match input such as
"{CONFIG..COMMENT, SPACE, '/', '='}" using multiple alternatives: 1,
2.
What's wrong with this grammar?

________________________________________________
grammar config;

options {
  language = Java;
  output = AST;
}

tokens {
  CONFIG;
  SECTION;
  SECTION_NAME;
  NODE;
  ATTRIBUTE;
  ATTR_NAME;
  ATTR_VALUE;
}

config	:	(COMMENT | section | EOL | SPACE)* -> ^(CONFIG COMMENT* section*);

section	:	section_header (EOL+ attribute)* -> ^(SECTION section_header
attribute*);

section_header
	:	'[' node+ ']' -> ^(SECTION_NAME ^(NODE node)+);

node	:	('/' ~(EOL | '#' | '[' | ']' | '/')*);

attribute	:	attr_name '=' attr_value -> ^(ATTRIBUTE ^(ATTR_NAME
attr_name) ^(ATTR_VALUE attr_value));

attr_name
	:	~(EOL | '#' | '[' | ']' | '=')+;
	
attr_value
	:	~(EOL | '#' | '[' | ']')+;

COMMENT :       ('#' (~('\n' | '\r'))* ('\n' | '\r' | '\r' '\n')?);

SPACE   :       (' ' | '\t' | '\f')+;

EOL     :       ('\n' | '\r' | '\r' '\n');
________________________________________________

Thanks.