public Expression GenCode(RHC rhc, ObjExpr objx, GenContext context)
{
Type collType;
if (_coll is IPersistentList)
collType = typeof(PersistentList);
else if (_coll is IPersistentVector)
collType = typeof(PersistentVector);
else if (_coll is IPersistentMap)
collType = typeof(PersistentArrayMap);
else if (_coll is IPersistentSet)
collType = typeof(PersistentHashSet);
else
throw new InvalidOperationException("Unknown collection type.");
return Expression.Field(null, collType, "EMPTY");
}