Curly braces ({}) are lexical equivalents to the keywords RECORD and END that can be used anywhere RECORD and END are appropriate. Either form (RECORD/END or {}) can be used to create "on-the-fly" record formats within those functions that require record structures (OUTPUT, TABLE, DATASET etc.), instead of defining the record as a separate definition.

All field declarations in a RECORD Structure must use one of the following syntaxes:

Field definitions must always define the datatype and identifier of each field, either implicitly or explicitly. If the RECORD structure will be used by TABLE, PARSE, ROW, or any other function that creates an output recordset, then the defaultvalue must also be implicitly or explicitly defined for each field. In the case where a field is defined in terms of a field in a dataset already in scope, you may name the identifier with a name already in use in the dataset already in scope as long as you explicitly define the datatype.

Field definitions may be inherited from a previously defined RECORD structure or DATASET. When a recstruct (a RECORD Structure) is specified from which to inherit the fields, the new fields are implicitly defined using the datatype and identifier of all the existing field definitions in the recstruct. When a sourcedataset (a previously defined DATASET or recordset definition) is specified to inherit the fields, the new fields are implicitly defined using the datatype, identifier, and defaultvalue of all the fields (making it usable by operations that require a data source, such as TABLE and PARSE). Either of these forms may optionally have its own identifier to allow reference to the entire set of inherited fields as a single entity.

You may also use logical operators (AND, OR, and NOT) to include/exclude certain fields from the inheritance, as described here:

The minus sign (-) is a synonym for AND NOT, so R1-R2 is equivalent to R1 AND NOT R2.

It is an error if the records contain the same field names whose value types don't match, or if you end up with no fields (such as: A-A). You must ensure that any MAXLENGTH/MAXCOUNT is specified correctly on each field in both RECORD Structures.

Example:

R1 := {STRING1 F1,STRING1 F2,STRING1 F3,STRING1 F4,STRING1 F5};
R2 := {STRING1 F4,STRING1 F5,STRING1 F6};
R3 := {R1 AND R2}; //Intersection - fields F4 and F5  only
R4 := {R1 OR R2}; //Union - all fields F1 - F6
R5 := {R1 AND NOT R2}; //Difference - fields F1 - F3
R6 := {R1 AND NOT F1}; //Exception - fields F2 - F5
R7 := {R1 AND NOT [F1,F2]}; //Exception - fields F3 - F5

//the following two RECORD structures are equivalent:
C := RECORD,MAXLENGTH(x)
  R1 OR R2;
END;
         
D := RECORD, MAXLENGTH(x)
  R1;
  R2 AND NOT R1;
END;

The following list of field modifiers are available for use on field definitions:

XPATH support is a limited subset of the full XPATH specification, basically expressed as:

node[qualifier] / node[qualifier] ...

These operators are valid for comparisons:

<, <=, >, >=, =, !=

An example of a supported xpath:

/a/*/c*/*d/e[@attr]/f[child]/g[@attr="x"]/h[child>="5"]/i[@x!="2"]/j

You can emulate AND conditions like this:

/a/b[@x="1"][@y="2"]

Also, there is a non-standard XPATH convention for extracting the text of a match using empty angle brackets (<>):

R := RECORD
STRING blah{xpath('a/b<>')};
//contains all of b, including any child definitions and values
END;

An XPATH for a value cannot be ambiguous. If the element occurs multiple times, you must use the ordinal operation (for example, /foo[1]/bar) to explicit select the first occurrence.

For XML or JSON DATASETs reading and processing results of the SOAPCALL function, the following XPATH syntax is specifically supported:

1) For simple scalar value fields, if there is an XPATH specified then it is used, otherwise the lower case identifier of the field is used.

STRING name;                  //matches: <name>Kevin</name>
STRING Fname{xpath('Fname')}; //matches: <Fname>Kevin</Fname>

2) For a field whose type is a RECORD structure, the specified XPATH is prefixed to all the fields it contains, otherwise the lower case identifier of the field followed by '/' is prefixed onto the fields it contains. Note that an XPATH of '' (empty single quotes) will prefix nothing.

NameRec := RECORD
  STRING Fname{xpath('Fname')}; //matches: <Fname>Kevin</Fname>
  STRING Mname{xpath('Mname')}; //matches: <Mname>Alfonso</Mname>
  STRING Lname{xpath('Lname')}; //matches: <Lname>Jones</Lname>
END;
          
PersonRec := RECORD
  STRING Uid{xpath('Person[@UID]')};
  NameRec Name{xpath('Name')};
    /*matches: <Name>
              <Fname>Kevin</Fname>
              <Mname>Alfonso</Mname>
              <Lname>Jones</Lname>
              </Name> */
END;

3) For a child DATASET field, the specified XPATH can have one of two formats: "Container/Repeated" or "/Repeated." Each "/Repeated" tag within the optional Container is iterated to provide the values. If no XPATH is specified, then the default value for the Container is the lower case field name, and the default value for Repeated is "Row." For example, this demonstrates "Container/Repeated":

DATASET(PeopleNames) People{xpath('people/name')};
          /*matches: <people>
                        <name>Gavin</name>
                        <name>Ricardo</name>
                    </people> */

This demonstrates "/Repeated":

DATASET(Names) Names{xpath('/name')};
          /*matches: <name>Gavin</name>
                     <name>Ricardo</name> */

"Container" and "Repeated" may also contain xpath filters, like this:

DATASET(doctorRec) doctors{xpath('person[@job=\'doctor\']')};
          /*matches: <person job='doctor'>
                       <FName>Kevin</FName>
                       <LName>Richards</LName>
                     </person> */

4) For a SET OF type field, an xpath on a set field can have one of three formats: "Repeated", "Container/Repeated" or "Container/Repeated/@attr". They are processed in a similar way to datasets, except for the following. If Container is specified, then the XML reading checks for a tag "Container/All", and if present the set contains all possible values. The third form allows you to read XML attribute values.

SET OF STRING people;
    //matches: <people><All/></people>
    //or: <people><Item>Kevin</Item><Item>Richard</Item></people>
         
SET OF STRING Npeople{xpath('Name')};
    //matches: <Name>Kevin</Name><Name>Richard</Name>
SET OF STRING Xpeople{xpath('/Name/@id')};
    //matches: <Name id='Kevin'/><Name id='Richard'/>

For writing XML or JSON files using OUTPUT, the rules are similar with the following exceptions:

Example:

For DATASET or the result type of a TRANSFORM function, you need only specify the value type and name of each field in the layout:

R1 := RECORD
  UNSIGNED1 F1; //only value type and name required
  UNSIGNED4 F2;
  STRING100 F3;
END;
          
D1 := DATASET('~LR::SomeFile',R1,THOR);      

For "vertical slice" TABLE, you need to specify the value type, name, and data source for each field in the layout:

R2 := RECORD
  UNSIGNED1 F1 := D1.F1; //value type, name, data source all explicit
  D1.F2; //value type, name, data source all implicit
END;

T1 := TABLE(D1,R2);

For "crosstab report" TABLE:

R3 := RECORD
  D1.F1;            //"group by" fields must come first 
  UNSIGNED4 GrpCount := COUNT(GROUP); 
                   //value type, column name, and aggregate
  GrpSum := SUM(GROUP,D1.F2); //no value type -- defaults to INTEGER
  MAX(GROUP,D1.F2); //no column name in output
END;

T2 := TABLE(D1,R3,F1);

Form1 := RECORD
    Person.per_last_name; //field name is per_last_name - size
                         //is as declared in the person dataset
    STRING25 LocalID := Person.per_first_name;
                        //the name of this field is LocalID and it
                        //gets its data from Person.per_first_name
    INTEGER8 COUNT(Trades); //this field is unnamed in the output file
    BOOLEAN HasBogey := FALSE; 
                        //HasBogey defaults to false
    REAL4    Valu8024;
          //value from the Valu8024 definition
END;
Form2 := RECORD
     Trades; //include all fields from the Trades dataset at their
            // already-defined names, types and sizes
     UNSIGNED8 fpos {VIRTUAL(fileposition)};
           //contains the relative byte position within the file
END;

Form3 := {Trades,UNSIGNED8 local_fpos {VIRTUAL(localfileposition)}};
          //use of {} instead of RECORD/END
          //"Trades" includes all fields from the dataset at their
          // already-defined names, types and sizes
          //local_fpos is the relative byte position in each part

Form4 := RECORD, MAXLENGTH(10000)
     STRING VarStringName1{MAXLENGTH(5000)};
          //this field is variable size to a 5000 byte maximum
 
     STRING VarStringName2{MAXLENGTH(4000)};
          //this field is variable size to a 4000 byte maximum

     IFBLOCK(MyCondition = TRUE) //following fields receive values
          //only if MyCondition = TRUE

     BOOLEAN HasLife := TRUE;
          //defaults to true unless MyCondition = FALSE

     INTEGER8 COUNT(Inquiries); 
          //this field is zero if MyCondition = FALSE, even
          //if there are inquiries to count

      END;
END;

in-line record structures, demonstrating same field name use

ds := DATASET('d', { STRING s; }, THOR);
t := TABLE(ds, { STRING60 s := ds.s; });
    // new "s" field is OK with value type explicitly defined

"Child dataset" RECORD structures

ChildRec := RECORD
    UNSIGNED4 person_id;
    STRING20 per_surname;
    STRING20 per_forename;
END;
ParentRecord := RECORD
    UNSIGNED8 id;
    STRING20 address;
    STRING20 CSZ;
    STRING10 postcode;
    UNSIGNED2 numKids;
    DATASET(ChildRec) children{MAXCOUNT(100)};
END;

an example using {XPATH('tag')}

R := RECORD
     STRING10 fname;
     STRING12 lname;
     SET OF STRING1 MySet{XPATH('Set/Element')}; //define set tags
END;
B := DATASET([{'Fred','Bell',['A','B']},
            {'George','Blanda',['C','D']},
            {'Sam','',['E','F'] } ], R);
         
OUTPUT(B,,'~LR::test.xml', XML,OVERWRITE);

/* this example produces XML output that looks like this:
<Dataset>
<Row><fname>Fred </fname><lname>Bell</lname>
 <Set><Element>A</Element><Element>B</Element></Set></Row>
<Row><fname>George</fname><lname>Blanda </lname>
 <Set><Element>C</Element><Element>D</Element></Set></Row>
<Row><fname>Sam </fname><lname> </lname>
<Set><Element>E</Element><Element>F</Element></Set></Row>
</Dataset>
*/

another XML example with a 1-field child dataset

cr := RECORD,MAXLENGTH(1024)
  STRING phoneEx{XPATH('')};
END;
r := RECORD,MAXLENGTH(4096)
  STRING id{XPATH('COMP-ID')};cr := RECORD,MAXLENGTH(1024)
  STRING phoneEx{XPATH('')};
END;
r := RECORD,MAXLENGTH(4096)
  STRING id{XPATH('COMP-ID')};
  STRING phone{XPATH('PHONE-NUMBER')};
  DATASET(cr) Fred{XPATH('PHONE-NUMBER-EXP')};
END;
         
DS := DATASET([{'1002','1352,9493',['1352','9493']},
            {'1003','4846,4582,0779',['4846','4582','0779']}],r);

OUTPUT(ds,,'~LR::XMLtest2',
      XML('RECORD',
          HEADING('<?xml version="1.0" encoding="UTF-8"?><RECORDS>',
                  '</RECORDS>')),OVERWRITE);
 
/* this example produces XML output that looks like  this:
<?xml version="1.0" encoding="UTF-8"?>
   <RECORDS>
      <RECORD>
         <COMP-ID>1002</COMP-ID>
          <PHONE-NUMBER>1352,9493</PHONE-NUMBER>
          <PHONE-NUMBER-EXP>1352</PHONE-NUMBER-EXP>
          <PHONE-NUMBER-EXP>9493</PHONE-NUMBER-EXP>
       </RECORD>
       <RECORD>
         <COMP-ID>1003</COMP-ID>
          <PHONE-NUMBER>4846,4582,0779</PHONE-NUMBER>
          <PHONE-NUMBER-EXP>4846</PHONE-NUMBER-EXP>
          <PHONE-NUMBER-EXP>4582</PHONE-NUMBER-EXP>
          <PHONE-NUMBER-EXP>0779</PHONE-NUMBER-EXP>
       </RECORD>
     </RECORDS>
 */

XPATH can also be used to define a JSON file

/* a JSON  file called "mybooks.json" contains this data:
[
  {
    "id" : "978-0641723445",
    "name" : "The Lightning Thief",
    "author" : "Rick Riordan"
  }
,
  {
    "id" : "978-1423103349",
    "name" : "The Sea of Monsters",
    "author" : "Rick Riordan"
  }
]
*/

BookRec := RECORD
  STRING ID {XPATH('id')}; //data from id tag -- renames field to uppercase
  STRING title {XPATH('name')}; //data from name tag, renaming the field
  STRING author; //data from author tag, tag name is lowercase and matches field name  
END;

books := DATASET('~LR::mybooks.json',BookRec,JSON('/'));
OUTPUT(books);

See Also: DATASET, DICTIONARY, INDEX, OUTPUT, TABLE, TRANSFORM Structure, TYPE Structure, SOAPCALL