anchor.diff:      : K_DROP K_KEYSPACE (K_IF K_EXISTS { if_exists = true; } )? ks=keyspaceName { $ksp = ::make_shared<drop_keyspace_statement>(ks, if_exists); }
       ;
   
  +/**
  + * DROP COLUMNFAMILY [IF EXISTS] <CF>;
  + */
  +dropTableStatement returns [::shared_ptr<drop_table_statement> stmt]
  +    @init { bool if_exists = false; }
  +    : K_DROP K_COLUMNFAMILY (K_IF K_EXISTS { if_exists = true; } )? cf=columnFamilyName { $stmt = ::make_shared<drop_table_statement>(cf, if_exists); }
  +    ;
  +
   #if 0
  -/**
  - * DROP COLUMNFAMILY [IF EXISTS] <CF>;
  - */
  -dropTableStatement returns [DropTableStatement stmt]
  -    @init { boolean ifExists = false; }
  -    : K_DROP K_COLUMNFAMILY (K_IF K_EXISTS { ifExists = true; } )? cf=columnFamilyName { $stmt = new DropTableStatement(cf, ifExists); }
  -    ;
  -
   /**
    * DROP TYPE <name>;
    */
  
positive.code:     | st9= createTableStatement        { $stmt = st9; }
      | st10=createIndexStatement        { $stmt = st10; }
      | st11=dropKeyspaceStatement       { $stmt = st11; }
  #if 0
      | st12=dropTableStatement          { $stmt = st12; }
      | st13=dropIndexStatement          { $stmt = st13; }
      | st14=alterTableStatement         { $stmt = st14; }
      | st15=alterKeyspaceStatement      { $stmt = st15; }
  
negative.code: #include "cql3/statements/create_index_statement.hh"
  #include "cql3/statements/create_table_statement.hh"
  #include "cql3/statements/property_definitions.hh"
  #include "cql3/statements/drop_table_statement.hh"
  #include "cql3/statements/truncate_statement.hh"
  #include "cql3/statements/select_statement.hh"
  #include "cql3/statements/update_statement.hh"
  