anchor.diff:  
   indexOption_
       : KEY_BLOCK_SIZE EQ_? NUMBER_ | indexType_ | WITH PARSER identifier_ | COMMENT STRING_ | VISIBLE | INVISIBLE
  +    ;
  +
  +constraintDefinition_
  +    : (CONSTRAINT ignoredIdentifier_?)? (primaryKeyOption_ | uniqueOption_ | foreignKeyOption_)
       ;
   
   primaryKeyOption_
  
positive.code:     : columnName dataType (inlineDataType_* | generatedDataType_*)
      ;
  
  indexDefinition_
      : (FULLTEXT | SPATIAL)? (INDEX | KEY)? indexName? indexType_? keyParts_ indexOption_*
      ;
  
  constraintDefinition_
      : (CONSTRAINT ignoredIdentifier_?)? (primaryKeyOption_ | uniqueOption_ | foreignKeyOption_)
      ;
  
  inlineDataType_
      : commonDataTypeOption_
      | AUTO_INCREMENT
  
negative.code:     | (VIRTUAL | STORED)
      ;
  
  indexDefinition_
      : (FULLTEXT | SPATIAL)? (INDEX | KEY)? indexName? indexType_? keyParts_ indexOption_*
      ;
  
  indexType_
      : USING (BTREE | HASH)
      ;
  