anchor.diff:  
   @parser::includes {
   #include "cql3/selection/writetime_or_ttl.hh"
  +#include "cql3/statements/alter_keyspace_statement.hh"
   #include "cql3/statements/alter_table_statement.hh"
   #include "cql3/statements/create_keyspace_statement.hh"
   #include "cql3/statements/drop_keyspace_statement.hh"
  
positive.code:       { $expr = new DropTriggerStatement(cf, name.toString(), ifExists); }
      ;
  
  /**
   * ALTER KEYSPACE <KS> WITH <property> = <value>;
   */
  alterKeyspaceStatement returns [AlterKeyspaceStatement expr]
      @init { KSPropDefs attrs = new KSPropDefs(); }
      : K_ALTER K_KEYSPACE ks=keyspaceName
          K_WITH properties[attrs] { $expr = new AlterKeyspaceStatement(ks, attrs); }
      ;
  #endif
  
  /**
   * ALTER COLUMN FAMILY <CF> ALTER <column> TYPE <newtype>;
  
negative.code:     | st13=dropIndexStatement          { $stmt = st13; }
  #endif
      | st14=alterTableStatement         { $stmt = st14; }
      | st15=alterKeyspaceStatement      { $stmt = st15; }
      | st16=grantStatement              { $stmt = st16; }
      | st17=revokeStatement             { $stmt = st17; }
      | st18=listPermissionsStatement    { $stmt = st18; }
  