[antlr-interest] "Comments" token from source to the target language
parrt at cs.usfca.edu
Mon Nov 12 17:19:10 PST 2007
Hi. Sure. Each token as an index into token buffer via
t.getTokenIndex(). Then ask for the token at index -1, -2, etc...
You can ask for it's channel number too. Just scan :)
On Nov 12, 2007, at 4:13 PM, Mateus Baur da Silva wrote:
> Hi Ter,
> I understand that parser will ignore the tokens if I set the token
> to be sent to the parser thru the hidden channel ($channel=HIDDEN;).
> By reading your message (and your book), I know I can check the
> hidden channel for the comments token inside my actions. However, I
> don't know how to do that. Is there some sample implementing this
> If not, could you (or someone else) let me know how I should
> implement that inside my actions?
> Thanks and Regards,
> On Nov 12, 2007 8:03 PM, Terence Parr < parrt at cs.usfca.edu> wrote:
> On Nov 12, 2007, at 11:38 AM, Mateus Baur da Silva wrote:
> > Hi Guys,
> > As I mentioned in some my other email, I doing a translator from a
> > Pascal subset to java. Currently, I'm ignoring the "comments" by
> > using skip() on the lexer rule that defines the "comments".
> > However, I would like to translate the comments from Pascal to Java
> > code as well. I was wondering if I could do that by using the
> > HIDDEN_CHANNEL or some other feature to properly translate the
> > comments. Does someone have any clue on how to do that?
> Yep, use the hidden token thing. Your actions then ask for the
> hidden tokens between real tokens. Parser ignores them.
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