At 08:25 16/12/2009, Peter Boughton wrote:
>The ANTLR book mentions auto-backtracking (which seems to be
what
>is *not* happening here), and which can be turned on with
"options
>{backtrack=true;}"
>
>Would that not solve this problem?
Unfortunately not; backtracking is a parser feature and doesn't
operate in the lexer.
>If so, are there any issues (aside from performance) that might
be
>a reason not to have this turned on?
The biggest problem with it (other than performance) is that it
can hide errors in the grammar, and lead to misleading error
messages while processing input (since when it finally does
produce an error, it's likely to be off in some weird part of the
rules).
But yes, it would be nice if lexing ambiguity could be dealt with
a little more automatically. But at the end of the day, fixing it
up yourself will improve performance, so it's not all bad news.
List: http://www.antlr.org/mailman/listinfo/antlr-interest
Unsubscribe:
http://www.antlr.org/mailman/options/antlr-interest/your-email-address
--
You received this message because you are subscribed to the Google Groups
"il-antlr-interest" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/il-antlr-interest?hl=en.
