Hi Terence,
> Yes. you must use
>
>> list : '(' listBody ')' -> ^(LIST listBody?)
>
> not
>
>> list : '(' listBody ')' -> ^(LIST listBody)
>
> clearly listBody can be optional, right?
Yes, in this case it is definitely optional. But, in the Java grammar
case it is not:
> classDeclaration
> : 'class' Identifier (typeParameters)?
> ('extends' type)? ('implements' typeList)?
> classBody
> ;
>
> ...
>
> classBody
> : '{' classBodyDeclaration* '}'
> ;
>
> ...
>
> classBodyDeclaration
> : ';'
> | ... [other productions]
> ;
I can't make classBody here optional, like e.g.:
> classDeclaration
> : 'class' Identifier (typeParameters)?
> ('extends' type)? ('implements' typeList)?
> classBody?
> -> ^(Class ...)
> ;
Otherwise, I'm accepting Java files which are not correct. It seems the
only option is to refactor giving this:
> classDeclaration
> : 'class' Identifier (typeParameters)?
> ('extends' type)? ('implements' typeList)?
> '{' (classBodyDeclaration | ';')* '}'
> -> ^(Class ...)
> ;
>
> ...
>
> classBodyDeclaration
> : ... [other productions]
> ;
But, this doesn't seem ideal to me?
Cheers,
Dave
>>> This seems clumsy, since neither the X or Y tokens are actually needed
>
> just use ? :)
>
> Ter
>
--
Lecturer in Computer Science,
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Victoria University of Wellington,
PO Box 600,
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