LPeg - AST / Tree walker?

[Lode Hoste <zillode@...>]

Hi,

After watching the talk about LPeg I was inspired to use it to
describe the grammar of my DSL.
I now have a complete PEG grammar (LPEG.RE) of about 300 lines, but
can't find a good pointer on how to generate an AST or parse tree with
callbacks from it.
Other PEG implementations do offer this functionality (e.g.
http://boshi.inimino.org/3box/PanPG/build/demo.html).

My manual work-around currently looks like this:

...
Constant                <- {<String> / <Integer> / <Float> / <Symbol>
/ <InstanceName>} -> constant
...

grammar = re.compile(dsl, {
       constant           = function(c) return {"constant", c} end,
})


Do I have to do this for every non-terminal I specified? Is there
a better way to do this?


Thanks,


Lode