[antlr-interest] ANTLR Grammar error - Illegal token.

[Jim Idle]

On Mon, 2008-08-04 at 09:52 -0700, rkevinburton at charter.net wrote:

> If I left factor the grammar I essentially have


Thsi is not left factored, you have just left factored the first bit of
it.

> 
> classSourceElement
> 	: classField
> 	| classMethod
> 	| classProperty
> 	;
> 
> classCommon
> 	:  (s=STATIC)? (modifier=(PUBLIC|PRIVATE))?
> 	;
> 		 
> classField
> 	: c=classCommon VAR name=Identifier
> 	-> ^( CFIELD $c $name )
> 	| c=classCommon VAR name=Identifier COLON type=Identifier
> 	-> ^( CFIELD $c $name TYPES $type)
> 	;


both of htese have a common prefix classCommon VAR Identifier, left
factor these.

> 
> classMethod
> 	: c=classCommon name=Identifier formalParameterList functionBody
> 	-> ^( $c formalParameterList functionBody )
> 	;


And so does this, 

You want to take all the classCommon stuff and start classSourceElement
with it, then you have classField as:

VAR name=Identifier 
        (    COLON type=Identifier ->^(CFIELD $name TYPES $type)
            | ->^(CFIELD $name)
        )

your classSourceElement the is:

classSourceElement
   : c=classCommon
           ( c1=classField
            | c2=classProperty
           etc.

and you rewrite as ^(TYPEDECL $c $c1? $c2? etc).

You AST walker can then semantically check whether static and so on are
valid for this declaration.
Jim
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