[antlr-interest] adding a subtree to the left side of a rewrite rule which doesn't have a corresponding left side element ?

[Terence Parr]

if newSubTree is some random tree you create not with antlr, then do

>> program : bla1 bla2 bla3 -> ^( 'P' bla1 bla2 {newSubTree} bla3 ) ;

T
On Jan 8, 2011, at 12:16 PM, Roland Braito wrote:

> Hi!
> 
> thanks for the quick reply!
> 
> However, the 'SL' token is not the problem, it's putting the list into a subtree and including that in the rewrite-rule's output.
> 
> I'm sure the answer is very obvious, but i'm unable to see it right now.
> 
> 
> Thanks,
> R.
> 
> 
> -------- Original-Nachricht --------
>> Datum: Sat, 8 Jan 2011 11:39:52 -0800
>> Von: Terence Parr <parrt at cs.usfca.edu>
>> An: r.b.lists at gmx.net
>> CC: antlr-interest at antlr.org
>> Betreff: Re: [antlr-interest] adding a subtree to the left side of a rewrite rule which doesn\'t have a corresponding left side element ?
> 
>> hi. search for keyword "imaginary token" or imaginary  node.
>> Ter
>> On Jan 8, 2011, at 11:05 AM, r.b.lists at gmx.net wrote:
>> 
>>> Hello All,
>>> 
>>> Sorry for the confusing title...
>>> 
>>> I'm trying to build an AST via rewrite rules.
>>> 
>>> The input is a DSL which contains a number of possible constructs, 
>>> including a description of state transitions.
>>> 
>>> I'd like to build a list 1of all the states mentioned and include that 
>>> list in the AST as something like ^( SL states+ )
>>> 
>>> What is the best way to do this?
>>> 
>>> I tried to build a separate rule to extract the states from the input 
>>> and insert it at the right side, but Antlr complains about referencing 
>>> something on the right side which doesn't show up on the left side...
>>> 
>>> example:
>>> 
>>> program : bla1 bla2 bla3 -> ^( 'P' bla1 bla2 newSubTree bla3 ) ;
>>> 
>>> leads to an error...
>>> 
>>> Then i tried to set up a global scope and collect all the names in it , 
>>> but i didn't find a way to transfer the list into a subtree from within 
>>> the grammar...
>>> 
>>> Do i really have to build the sub-tree by hand and include it manually, 
>>> or is there a more efficient way?
>>> 
>>> Thanks,
>>> R.
>>> 
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> 
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