[antlr-interest] Custom AST node type - guidance needed
Bill Andersen
andersen at highfleet.com
Mon Jul 19 13:02:57 PDT 2010
Thanks Jay
That did it.
On Jul 19, 2010, at 15:52 , Junkman wrote:
> Hi Bill,
>
> You have
>
> import antlr.*;
>
> instead of
>
> import org.antlr.runtime.*;
>
> Maybe that's the problem?
>
> org.antlr.runtime.CommonToken implements org.antlr.runtime.Token, so
> explicit casting seems out of wack.
>
> Jay
>
>
> Bill Andersen wrote:
>> Thanks John
>>
>> Below is my class def.. Eclipse tells me the casts to Token below are required. Running a grammar that executes these constructors tells me I can't cast to Token.
>>
>> Here's a sample tree building expression where this class is used.
>>
>> ^(AS_TYPE_LIST<ASNode>[s.getType($ID.text)] ID)
>>
>> the getType method just looks up a ASType object by name from a table.
>>
>> import org.antlr.runtime.tree.*;
>>
>> import antlr.*;
>>
>> public class ASNode extends CommonTree {
>>
>> public ASType type = null;
>>
>> public ASNode() { }
>>
>> public ASNode(int ttype, ASType type) {
>> token = (Token) new CommonToken(ttype,"");
>> this.type = type;
>> }
>>
>> public ASNode(int ttype) {
>> token = (Token) new CommonToken(ttype,"");
>> }
>>
>> @Override
>> public String toString() {
>> return (token!=null?token.getText():"")+"<ASNode>;"+type;
>> }
>>
>> @Override
>> public Tree dupNode() {
>> ASNode n = new ASNode();
>> n.token = token;
>> n.type = type;
>> return n;
>> }
>>
>> }
>>
>> On Jul 19, 2010, at 15:15 , John B. Brodie wrote:
>>
>>> On Mon, 2010-07-19 at 14:29 -0400, Bill Andersen wrote:
>>>> Hi folks
>>> Greetings!
>>>
>>>> Having some trouble making ASTs using a custom node type. Before I ask any stupid questions, what is the best place to look on how to do this ( I'm using 3.2 )? I'm finding bits and pieces, some of them contradictory. For example I find this example
>>>>
>>>> static class V extends CommonTree {
>>>> public int x,y,z;
>>>> public V(int ttype, int x, int y, int z) {
>>>> this.x=x; this.y=y; this.z=z; token=new CommonToken(ttype,"");
>>>> }
>>>> at http://www.antlr.org/wiki/display/ANTLR3/Tree+construction
>>>>
>>>> When I try to define a constructor like this I'm forced to put a cast between on CommonToken to Token, which causes a runtime can't cast error.
>>>>
>>>> What I want is really quite simple. Need to add one extra field to my AST nodes to carry DSL type information.
>>>>
>>>> Any help appreciated. Thanks.
>>> Unable to reproduce.
>>>
>>> Attached please find a complete example derived from the grammar on the
>>> above wiki page that uses the class V. maybe I'm using a different
>>> example than yours?
>>>
>>> Need more info....
>>> -jbb
>>>
>>> <T.g>
>>
>> Bill Andersen
>> Highfleet, Inc. (www.highfleet.com)
>> 3600 O'Donnell Street, Suite 600
>> Baltimore, MD 21224
>> Office: +1.410.675.1201
>> Cell: +1.443.858.6444
>> Fax: +1.410.675.1204
>>
>>
>>
>>
>>
>>
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>
Bill Andersen
Highfleet, Inc. (www.highfleet.com)
3600 O'Donnell Street, Suite 600
Baltimore, MD 21224
Office: +1.410.675.1201
Cell: +1.443.858.6444
Fax: +1.410.675.1204
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