[antlr-interest] The following alternatives can never be matched

Markus Lottmann lottvomschlott at gmx.de
Mon Dec 6 09:20:38 PST 2010


Hi,

i am quite new to antlr and dont understand whats wrong with the 
following grammar:

grammar test2;
options{
backtrack=false;
}
octal_literal
     :    '0' octal_digit*;

octal_digit
     :    '0'..'7';

The error is:

[18:17:06] warning(200): test2.g:6:8: Decision can match input such as 
"EOF" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
[18:17:06] error(201): test2.g:6:8: The following alternatives can never 
be matched: 2

Thanks so far.
Greetings,
ML


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