[antlr-interest] Understanding priorities in lexing (newbie)
Terence Parr
parrt at cs.usfca.edu
Thu Jul 12 16:23:05 PDT 2007
On Jul 12, 2007, at 4:07 PM, Micheal J wrote:
>> Yes. ANTLR doesn't do the natural thing here. For normal cases,
>> it's not an issue. Few tokens are prefixes like that.
>> Normally it's
>> keyword against 'a'..'z'+ not 'a'..'z'.
>
> What would it take to alter the prediction strategy/algo to do the
> "natural
> thing" even in the presence of token prefixes like these?
>
> Just trying to get an idea of the work involved. I can see how this
> might be
> an issue to some.
It's hard in a recur. desc. parser because you have to longjump from
one method to another. Note sure how it could be done without
merging rules.
Maybe I could look into doing the (...)* not (...) for implicit
Tokens rule to see if it generates more "correct" DFA?
Ter
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