[antlr-interest] Lexer modes
Loring Craymer
lgcraymer at yahoo.com
Tue Sep 5 11:23:45 PDT 2006
Ter--
Lexer modes may be very easy to implement. Have multiple mToken (single token returned) rules underneath mTokens selected by sempreds. Syntax might be
mode FOO {
TEXT, NUMBER, 'hello'
}
to list the rules recognized in a mode. Multiple mTokens_ might be faster, and could be done easily if empty rules with sempreds work:
TOMBSTONE
:
{ mode != lastMode }? { lastMode = mode }?
;
Then you could follow the mTokens_ loops with TOMBSTONE as a termination condition and have a master mTokens rule.
Much of the simplicity comes from the artificially generated mTokens approach that you already have in place--that's a very clever way of letting ANTLR do the analysis.
--Loring
Terence Parr <parrt at cs.usfca.edu> wrote:
On Sep 1, 2006, at 12:32 PM, FranklinChen at cmu.edu wrote:
> Is there an estimate on when an ANTLR with lexer modes will be
> available? I have been holding off on implementing part of a program
> until this feature exists.
I am not sure about timing, but I want these for sure.
Ter
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