[antlr-interest] unable to run or debug grammar in antlrworks 1.4 on Windows XP
William Clodius
wclodius at los-alamos.net
Sat Jul 3 14:05:40 PDT 2010
On Jul 3, 2010, at 2:58 PM, Matt Palmer wrote:
> Well, this gets wierder, and to my mind seems to point to a bug in
> Antlrworks itself.
>
> I verified that I could consistently run the debugger using one simple
> grammar, but not another. On the non-working grammar, I commented out rules
> and tokens (starting from the most complex), until, lo-and-behold, after one
> rule went the debugger started working. I then re-enabled all the other
> rules one by one, and the grammar kept working. The lexer rule that wasn't
> working was a literal followed by a fragment, looking like this:
>
> BITMASK : '&' HEX_BYTE ;
>
> I then re-enabled this rule... and the debugger kept working. The only
> difference at this point between where I started with a non-working debugger
> and where I finished with a working debugger is I moved a couple of rules to
> the end (comments and whitespace both going to hidden channels) to simplify
> commenting them out.
>
> I've faced this problem before, I still have no idea what causes it and how
> to fix it. Maybe this will make sense to someone.
>
> Matt.
<snip>
Normally I would expect bitmask to be a syntactic element not a lexical element. If so then change all occurrences of BITMASK to bitmask. Otherwise have youm marked HEX_BYTE as a fragment?
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