[antlr-interest] wildcard in tree grammar

[Oliver Zeigermann]

My use case was just traversing a tree, not matter how it looks.

But having

^(. ID)

could mean "anything that has an ID as its first child". No idea what
would be the use case, so I know where you are coming from. Maybe just
add it for the sake of completeness and so that my tree rule finally
works?

Oliver

2008/11/30 Terence Parr <parrt at cs.usfca.edu>:
> not sure.  I guess i left out as it's weird.  When would you write: ^(. ID).
>  It's always the root that says what kind of thing it is, right?
>
> added
>
> http://www.antlr.org:8888/browse/ANTLR-368
>
> Ter
> On Nov 30, 2008, at 1:55 AM, Oliver Zeigermann wrote:
>
>> Great. Thanks!
>>
>> Can we expect that in 3.2?
>>
>> Oliver
>>
>> 2008/11/30 Terence Parr <parrt at cs.usfca.edu>:
>>>
>>> I agree. '.' as root should be ok.  I'll have to go back and make it
>>> context
>>> sensitive.  Right now, '.' can be a subtree as well.  it would mess up
>>> analysis.
>>> Ter
>>> On Nov 29, 2008, at 3:23 PM, Gavin Lambert wrote:
>>>
>>>> At 09:58 30/11/2008, Oliver Zeigermann wrote:
>>>>>
>>>>> Hmmm. Just checked that with the latest snapshot of ANTLR 3.2,
>>>>> but it really does not work, but it should, right? Why can "."
>>>>> not be a tree root?
>>>>
>>>> Yes, that's what Sam Harwell and myself were discussing earlier in this
>>>> thread; I think we agree that this should be considered as valid.
>>>>
>>>> (I gave a detailed description of how I think it should behave earlier
>>>> on,
>>>> but the general idea was to make ANTLR parse the tree as if it were a
>>>> "real"
>>>> tree rather than the "flat" tree that it's actually implemented as.)
>>>>
>>>
>>>
>
>