Disclaimer: I'm a noob. :)
Taking the newline out of comment seems to work, like this:
COMMENT : '#' (~( '\r' | '\n' ))* ;
NEWLINE : '\r'? '\n'
{
// kick it off to the hidden channel
// $channel=HIDDEN;
// or skip it altogether
// skip();
}
;
Last line comment terminating in EOF presents no problem.
I've seen this pattern for comment in other examples.
Don't know how/why debuggerLexer changes the outcome, but I assume you
can always trace the generated lexers to see how the different outcomes
result.
J
Nathan Eloe wrote:
>
> On Jun 1, 2010, at 1:33 PM, [email protected] wrote:
>
>> 6/1/2010 3:33 PM keltezéssel, Nathan Eloe írta:
>>> -----BEGIN PGP SIGNED MESSAGE-----
>>> Hash: SHA1
>>>
>>> Hello all,
>>> I'm working on an AST parser for the Bash language and I've come across the
>>> following strange behavior:
>>> I'm trying to handle comments, so I used the comments token you can get
>>> when you start a new grammar in ANTLRworks. It works.
>>>
>>> COMMENT
>>> : '#' ~('\n'|'\r')* '\r'? '\n' {$channel=HIDDEN;}
>>> ;
>>>
>>> The problem arises when the comment is the last thing from the input (i.e,
>>> no new line before EOF). Removing the '\n' from the token causes it to
>>> freak out when I run the tests, but I can't get it to match comments at the
>>> end of file. Leaving that '\n' in lets the code compile, but I still can't
>>> match that last case.
>>>
>>> Here's where the interesting part happens. When I run it through the
>>> debugger with the same test case that I use in gunit, the debugger allows
>>> the input and parses it correctly (meaning, it ignores it as it should) and
>>> correctly generates the expected AST.
>>>
>>> Does the debugger allow the code to be more robust in its decision making
>>> abilities? Or does it do something to the input to allow it to be matched
>>> to a token.
>>>
>>> Thanks for the help!
>>>
>>> Nathan
>>>
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