[antlr-interest] NoViableAlt

[Rick Mann]

Why do I get a "NoViableAltException" when parsing "3", but when parsing "asd" I get "asd" (in the ANTLRWorks Interpreter):

top	:	 expr;

expr	:	multExpr (('+'|'-') multExpr)*;
multExpr:	atom ('*' atom)*;
atom	:	NUM | ID | '(' expr ')';

LETTER	:	'a'..'z' | 'A'..'Z';
DIGIT	:	'0'..'9';
ID	:	LETTER (LETTER | DIGIT)*;
NUM	:	DIGIT+ ('.' DIGIT+)?;

TIA,
-- 
Rick