[antlr-interest] Abstract tree parser

[Christian Pontesegger]

I still don't get it:

Here is my treegrammar:

tree grammar IScriptCompiler;

options {
  language = Java;
  tokenVocab = IScript;
  ASTLabelType = CommonTree;
}

@header {
    package com.something.test;
}

@members {

    protected abstract void foo();

}

program
    :    globalStatement*
    ;

... to be continued




Now what I get is a java class like this:


public class IScriptCompiler extends TreeParser {

    <snip>

        protected abstract void foo();

...

This is not valid java code!

I need something like this

abstract public class IScriptCompiler extends TreeParser {

    <snip>

        protected abstract void foo();


How do I get this little "abstract" modifier in front of the class name?


BTW:
What should

	protected abstract void foo() {}

do? A body for an abstract method???


Christian


On 24.02.2010 20:38,  Terence Parr wrote:
> oh, i do:
>
> protected abstract void foo() {}
>
> Ter
> On Feb 24, 2010, at 11:36 AM, Christian Pontesegger wrote:
>
>   
>> Terence Parr wrote:
>>     
>>> You can either define abstract methods within @members and then subclass the parser or you can create a subclass of Parser with the abstract methods or concrete methods then use superClass.
>>>
>>>       
>> Thats what I intend to do, have
>>
>> @members {
>>
>>    protected abstract void foo();
>>    ...
>> }
>>
>> but then the generated class will have an error due to the missing
>> "abstract" modifier in the class definition. Unfortunately the @headers
>> section is pasted right before some other imports. If it were the last
>> before the class definition I could put my "abstract" modifier there.
>>
>> I want to derive from my abstract parser and have several implementing
>> parsers with different functionality. Right now I am declaring dummy
>> methods within @members and overwrite them in my subclasses. But thats
>> not the way java is meant to be, right?
>>
>> So if it is not possible to do that now, maybe this is some input for a
>> future version of ANTLR.
>>
>> Christian
>>
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>>     
>