[antlr-interest] superClass usage

[Terence Parr]

see

http://www.antlr.org/wiki/display/~admin/2007/07/18/On+the+reuse+of 
+grammars

for my initial thoughts; i still need to write doc.
Ter
On Nov 13, 2007, at 3:23 PM, Paul Keir wrote:

> Thanks Oti. Yeah, I finally realised I was hoping for too much from  
> superClass. It seems like grammar inheritance is only something for  
> the antlr wishlist.
> Paul
>
> Oti wrote:
>> Paul,
>>
>> you are talking about grammar inheritance - sorry no experience  
>> with that.
>> What I meant was putting most of the @member stuff, exception  
>> handling
>> and the like into a simple java super class.
>> This keeps your grammar cleaner, and simplifies unit testing.
>>
>> Best wishes,
>> Oti.
>>
>> On Nov 5, 2007 10:30 PM, Paul Keir <paul at paulkeir.com> wrote:
>>
>>>  Thanks. But how can I use a parser rule from a grammar's  
>>> superClass?
>>> Taking, say, the SimpleC.g Java example Grammar, I create a new  
>>> test file,
>>> Mine.g:
>>>
>>>  grammar Mine;
>>>
>>>  options {
>>>    superClass=simpleCParser;
>>>  }
>>>
>>>  catchme
>>>  : variable | declarator
>>>  ;
>>>
>>>  When I then run,
>>>  java org.antlr.Tool SimpleC.g Mine.g
>>>  it fails due to the 'variable' and 'declarator' rules being  
>>> undefined.
>>>
>>>  Thanks again,
>>>  Paul
>>>
>>>
>>>
>>>  Oti wrote:
>>>  Paul,
>>>
>>> for the parser superclass, it is really that easy as described in  
>>> section
>>> 5.7.
>>> Currently there is no way of specifiying the lexer superclass.  
>>> But you
>>> can use a package trick in Foo.g:
>>>
>>> @lexer::header {
>>> package my.lexer;
>>> }
>>>
>>> If you create a class named "Lexer" (which extends
>>> org.antlr.runtime.Lexer) in package my.lexer, your own Lexer will be
>>> the superclass. That's because ANTLR generates:
>>>
>>> package my.lexer;
>>> import org.antlr.runtime.*;
>>> public class FooLexer extends Lexer {...
>>>
>>> Hope this helps a little,
>>> Oti.
>>>
>>>
>>> On 10/28/07, Paul Keir <paul at paulkeir.com> wrote:
>>>
>>>
>>>  Hi all,
>>>
>>> Does anyone have an example using the superClass option described in
>>> section 5.7 of the ANTLR ref. book? I'd like to extend an existing
>>> combined grammar.
>>>
>>> Thanks in advance,
>>> Paul
>>>
>>>
>>>
>>>
>>>
>>>
>>

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