[antlr-interest] Grammar refuses to compile (Simple ANTLR gotcha)

[Ilia Kantor]

Hello,

Haven't used antlr for a bit... And need to write a grammar once again =)
Version is:3.0b7

This grammar doesn't compile (ambiguitiy)

I want "rule_call" to match "#a.b.c" from arbitrary text

Could you please explain what's the reason of error I have here and how to fix it ?

warning(200): My.g:8:24: Decision can match input such as "DOT WORD" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
warning(200): My.g:8:24: Decision can match input such as "MINUS GT WORD" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input


-----------------------------------------

document:
	(text | rule_call)+;
        
rule_call: 
		GET_SCOPE_VALUE WORD rule_long_def_part+;
	
rule_long_def_part
	:	
	(MINUS GT WORD) => MINUS GT WORD | 
	(DOT WORD) => DOT WORD;
	

text:
	DOT | MINUS | WORD | WS| GT | SPECIAL_CHAR ;




LCURL	:	'{';
RCURL	:	'}';

GET_SCOPE_VALUE
	:	'#';
	

DOT	:	'.';



MINUS
	:	'-';

GT	:	'>';

SPECIAL_CHAR
	:	'`' | '!' | '@' | '$' | '%' | '^' | '&' | '*' | '(' | ')' |  
	'+' | '=' | '[' | ']' | ';' | ':' | '\'' | '"' | '\\' | '|' | ',' | '<' |
	 '/' | '?';
	


fragment WS_CHAR  :
       (' '|'\r'|'\t'|'\u000C'|'\n' )
    ;
    
WS	:	WS_CHAR+;

// not SPECIAL_CHAR not WS_CHAR
WORD:	
	(~ ('`' | '!' | '@' | '$' | '%' | '^' | '&' | '*' | '(' | ')' |  
	'+' | '=' | '[' | ']' | ':' | '\'' | '"' | '\\' | '|' | ',' | '<' | '/' | '?'
	| '{' | '~' | '}' | '#' | ';' | '.' | '-' | '>'	| ' '|'\r'|'\t'|'\u000C'|'\n' ) )+ 
;