[antlr-interest] Re: Trouble modifying Java source w/ ANTLR

[cliftonccraig]

I think I finally got it! I just start with the index of the
identifier under the variableDeclarator rule and advance past the
white space to get my starting point. I then advance to the SEMI token
to get my stopping point and viola! Heres what I have so far:

variableDeclarator![AST mods, AST t]
	:	id:IDENT d:declaratorBrackets[t] v:varInitializer
		{
		    //*CCC- scan here for version indentifiers and replace the
initializer with the new value.
		    if(id.getText().equals("VERSION"))
		    {
		        int start = ((TokenWithIndex)id).getIndex() + 1, stop = start;
		        TokenWithIndex next = engine.getToken(start);
		        //Skip white space...
		        while(next.getType()==WS) {start++; next =
engine.getToken(start);}
		        //Advance to SEMI identifier...
		        stop = start;
		        while(next.getType()!=SEMI) {stop++; next =
engine.getToken(stop);}
                stop--; //Don't include the SEMI in the replacement.
		        engine.replace(start,stop,"= \"MODIFIED!\"");
		    }
		    #variableDeclarator = #(#[VARIABLE_DEF,"VARIABLE_DEF"], mods,
#(#[TYPE,"TYPE"],d), id, v);
		}
	;

Whew! I thought this would've ended up to be over a week-long project
but Ive only spent a couple days. All I need now is to parameterize
the whole thing so it can be a usefule re-usable component. Thnax
everyone!

Cliff


--- In antlr-interest at yahoogroups.com, "cliftonccraig" <ccc at i...> wrote:
> Thank you everyone,
> 
> The thing is I'm new to both grammar engines and sed. So to me it's
> the lesser of two evils. I've gotten a little further in this as I've
> been able to figure out the Java grammar a little more. So far I've
> narrowed where my mods go to the variableDeclarator rule. This is what
> I have so far:
> variableDeclarator![AST mods, AST t]
> 	:	id:IDENT d:declaratorBrackets[t] v:varInitializer
> 		{
> 		    //*CCC- scan here for version indentifiers and replace the
> initializer with the new value.
> 		    if(id.getText().equals("VERSION"))
> 		    {
> 		        int start = ((TokenWithIndex)id).getIndex() + 1,
> 		        stop = start + #d.getNumberOfChildren() +
> #v.getNumberOfChildren() - 1;
> 		        //System.out.println("Starting from " + start + " ending at
> " + stop);
> 		        //System.out.println("prevToken ==" + prevToken);
> 		        engine.replace(start,stop,"\"MODIFIED!\"");
> 		    }
> 		    #variableDeclarator = #(#[VARIABLE_DEF,"VARIABLE_DEF"], mods,
> #(#[TYPE,"TYPE"],d), id, v);
> 		}
> 	;
> 
> It gets a little hairy because the "stuff" I want to replace is not
> defined as tokens in the grammar, rather they're defined as parser
> rules. The rewrite engine example shows replacment using tokens but I
> don't know how to get an accurate token count from the two AST objects
>  at this point. I know the one (#d) is really just a place holder as
> there will be no array declaration here but the other does not seem to
> be yielding the right amount of child nodes. I think I'm at a
> misunderstanding here (child-nodes != tokens)? When I run everything
> with my above mods I get something like the following:
> public final static String VERSION"MODIFIED!"= "2.3";
>  where it clearly looks like the node count is evaluating to one and
> the token count is much higher (accomodating for whitespace and such).
> I don't want to hard code this because the version assignment may not
> always be a simple assignment. It could be an expression and I want to
> be able to replace the whole expression. Could you steer me in the
> right direction here?
> 
> Cliff
> 



 
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