[antlr-interest] Problems defining StringLiteral processing in a grammar

[Gavin Lambert]

At 09:41 16/12/2008, James Abley wrote:
 >My grammar contains the following rule:
 >
 >stringLiteral	:	'"'  (~'"')* '"'
 >	|	'\'' (~'\'')* '\''
 >	;
[...]
 >Using the ANTLR 3.0.1 runtime, I'm seeing unexpected behaviour 
in
 >that having certain characters; e.g. '?', '!'; in my literal
 >strings are proving problematic.
 >
 >line 1:27 no viable alternative at character '!'
 >line 1:61 no viable alternative at character '?'

This needs to be a lexer rule (initial capital letter, eg. 
StringLiteral) in order to work.  Using ~ in a parser rule means 
"any *token* except these" and is almost never what you really 
want.