int ebnf = 0;
if ( ebnfRoot!=null ) ebnf = ebnfRoot.getType();
Choice c = null;
switch ( ebnf ) {
case ANTLRParser.OPTIONAL :
c = new OptionalBlock(this, ebnfRoot, alts);
break;
case ANTLRParser.CLOSURE :
c = new StarBlock(this, ebnfRoot, alts);
break;
case ANTLRParser.POSITIVE_CLOSURE :