[antlr-interest] non-determinism.

[mzukowski at yci.com]

remove your AT rule and then add a literal keyword AT='@' to the keywords
section and test for it in TOKEN by turning on the option testLiterals=true.
See the docs on literals.

Monty

-----Original Message-----
From: mark kant [mailto:markkant2001 at yahoo.com]
Sent: Tuesday, March 25, 2003 9:42 AM
To: antlr-interest at yahoogroups.com
Subject: [antlr-interest] non-determinism.


Hi,

I get non-determinism in the following lexer (relevant
portion of parser and lexer)

hosport: host COLON password

password: TOKEN

host: NAME AT TOKEN


lexer ...............

COLON: ':'

SEMI: ';'

AT: '@'

TOKEN: ('a'..'z' | 'A'..'Z'
|'0'..'9'|'.'|':'|';'|'@')+


What is the best way to resolve it:
1. multiple lexers
2. syntactic predicates - not appropriate as I have
other similar rules for special characters
3. some kind of flag set in parser and lexer checks it
before matching a rule in lexer (how do I communicate
the flag state from parser to lexer). I have done this
in Lex and YAcc.

Thanks

Mark

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