[antlr-interest] Token Stream Rewriting
Fabien Hermenier
hermenierfabien at gmail.com
Tue Jun 21 23:30:31 PDT 2011
In fact, I've badly readed the help. So yet, it is running a String that
should be tokenized (then translated into tree I suppose) at run time.
Le 22/06/11 00:28, Bart Kiers a écrit :
> Is your `merge(String, List, String)` method returning
> a java.util.ArrayList instead of a Tree?
>
> Regards,
>
> Bart.
>
>
> On Wed, Jun 22, 2011 at 8:04 AM, Fabien Hermenier
> <hermenierfabien at gmail.com <mailto:hermenierfabien at gmail.com>> wrote:
>
> Hi
>
> I have some troubles with token stream rewriting. Below is the
> piece of
> ANTLR code. I have a grammar, with an AST as output and Java
> as the target. I want to insert a sequence of token into the stream.
>
> I have followed the page
> http://www.antlr.org/wiki/display/~admin/2007/06/28/Token+stream+rewriting+with+rewrite+rules
> <http://www.antlr.org/wiki/display/%7Eadmin/2007/06/28/Token+stream+rewriting+with+rewrite+rules>
> and adapted the example that interest me. A piece of the code is
> following. Basically, in the alternative of 'explodedSet', I get the
> return values of other rules and do some stuff in the merge
> method. This
> one returns a list of String as explained in the online example.
>
>
> explodedSet: '{' (setContent (',' setContent)*)? '}' -> ^(EXPLODED_SET
> setContent+)
> | {List l = new LinkedList();}LEFTY
> r1=brace_content{l.add($r1.ret);} (','
> r2=brace_content{l.add($r2.ret);})* RIGHTY
> -> {
> merge($LEFTY.text,l,$RIGHTY.text)
> };
>
> brace_content returns [List ret]:
> st=number ('..' ed=number)? {$ret = new LinkedList(); for
> (int
> i = $st.val; i <= $ed.val; i++) {$ret.add(i);}}
> | NAME {$ret = new LinkedList(); $ret.add($NAME.text);};
>
> The code compiles well but at runtime, I've got this exception:
>
> Caused by: java.lang.ClassCastException: java.util.ArrayList cannot be
> cast to org.antlr.runtime.tree.Tree
> at
> org.antlr.runtime.tree.BaseTreeAdaptor.addChild(BaseTreeAdaptor.java:107)
> at Parser.explodedSet(Parser.java:560)
>
> So, the return value of merge does not seems to be converted into
> tokens
> nor Tree. Does someone has an idea ?
>
>
> Fabien.
>
> List: http://www.antlr.org/mailman/listinfo/antlr-interest
> Unsubscribe:
> http://www.antlr.org/mailman/options/antlr-interest/your-email-address
>
>
--
Fabien Hermenier
Postdoctoral researcher at Flux
http://sites.google.com/site/hermenierfabien/home
More information about the antlr-interest
mailing list