[antlr-interest] Multiple pass tree walking Q

[Hill, Robert]

I've pretty much gone down the multiple tree parser routes, its a real
pain in the ass though, as if you modify your parser, you then have to
modify all the tree parser grammars too. I must be missing something
here. :(
there must be a rule that ignores a whole branch, but i've tried all
sorts and haven't succeeded , 
 
ignoreme : ^(.*) ... if only :)
 
which is why i ended up with 3 tree parse phases. I just get this
nagging feeling im missing the point.
 
i think everyone's gone on holiday, the list is usually way busier than
this.
 
cheers,
Rob
 



-- 
Rob Hill 
EDS - Hallamshire Business Park 
F1E/045 
Sheffield       
T:      +44 (0) 114 291 1928 
M:      +44 (0) 791 732 1227 
E:      rhill03 at eds.com <mailto:rhill03 at eds.com>  

 


________________________________

	From: Henry Butowsky [mailto:henryb at ntlworld.com] 
	Sent: 03 October 2006 15:46
	To: Hill, Robert
	Subject: Re: [antlr-interest] Multiple pass tree walking Q
	
	
	Hi Rob --- 
	    I have a similar problem  -- I Have to parse the tree twice
--- And Im not sure to use a single multipurpose tree walker or
	     use 2 tree parsers --- I will be watching the responses
from the newsgroup !
	
	Regards Henry
	
	Hill, Robert wrote: 

		I want to make multiple passes over a tree but only
utilise parts of the tree for each pass so I've duplicated the tree
grammar 3 times , adding actions only for the parts that matter at each
pass.

		So the question is , how do you ignore (remove) whole
branches of a tree? At the moment if I add a node into the parser output
I have to change all 3 tree walkers in response. If I know that the
tokens that pass 1 will no longer be affected, how can I remove all the
unwanted rules from that grammar so It only looks at the tokens it
needs?

		Am I approaching this in the correct manner? 

		Cheers! 

		Rob 








		-- 
		ROB HILL 
		DWP ACW 
		EDS Hallamshire Business Park 
		F1E/045 
		Sheffield       
		T:      +44 (0) 114 291 1928 
		M:      +44 (0) 790 318 5516 
		E:      rhill03 at eds.com <mailto:rhill03 at eds.com>  



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