[antlr-interest] lexer woes

[Gavin Lambert]

At 11:35 5/03/2008, Loring Craymer wrote:
 >> 1) Whether backtracking mode is supported for lexers,
 >1.)  Yes--see calls to prefixWithSynPred() in antlr.g

I think that answer is a little misleading :)

As far as I know, the "backtrack=true" option has no effect in the 
lexer.  However, backtracking in general is supported through 
adding your own syntactic predicates.

Note that syntactic predicates can only be used to disambiguate 
between alts in a single rule -- you can't use them to distinguish 
between tokens at the top level.  (If you need to do that, you'll 
have to merge the rules.)