DICTIONARY as a Value Type

DICTIONARY as a Value Type
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The second form of DICTIONARY is a value type with the structure parameter specifying the RECORD structure of the data. This data type usage allows you to specify a DICTIONARY as a child dataset, similar to the way DATASET may be used to define a child dataset. This may also be used to pass a DICTIONARY as a parameter.

Example:

ColorCodes := DATASET([{'Black' ,0 },
                       {'Brown' ,1 },
                       {'Red'   ,2 },
                       {'Orange',3 },
                       {'Yellow',4 },
                       {'Green' ,5 },
                       {'Blue'  ,6 },
                       {'Violet',7 },
                       {'Grey'  ,8 },
                       {'White' ,9 }], {STRING color,UNSIGNED1 code});

ColorCodesDCT := DICTIONARY(ColorCodes,{Color,Code});    //multi-field key
ColorCodeDCT  := DICTIONARY(ColorCodes,{Color => Code}); //payload field
CodeColorDCT  := DICTIONARY(ColorCodes,{Code => Color});

//mapping examples
MapCode2Color(UNSIGNED1 code) := CodeColorDCT[code].color;
MapColor2Code(STRING color)   := ColorCodeDCT[color].code;

OUTPUT(MapColor2Code('Red'));     //2
OUTPUT(MapCode2Color(4));         //'Yellow'

//Search term examples
OUTPUT('Green' IN ColorCodeDCT);  //true
OUTPUT(6 IN CodeColorDCT);        //true
OUTPUT(ROW({'Red',2},RECORDOF(ColorCodes)) IN ColorCodesDCT); //multi-field key, true 

//multi-field payload examples
rec := RECORD
  STRING10  color;
  UNSIGNED1 code; 
  STRING10  name;
END;
Ds := DATASET([{'Black' ,0 , 'Fred'},
               {'Brown' ,1 , 'Seth'},
               {'Red'   ,2 , 'Sue'},
               {'White' ,3 , 'Jo'}], rec);

DsDCT := DICTIONARY(DS,{color => DS});

OUTPUT('Red' IN DsDCT); //true
DsDCT['Red'].code;      //2
DsDCT['Red'].name;      //Sue

//inline DCT examples
InlineDCT := DICTIONARY([{'Black' => 0 , 'Fred'},
                         {'Brown' => 1 , 'Sam'},
                         {'Red'   => 2 , 'Sue'},
                         {'White' => 3 , 'Jo'} ], 
                        {STRING10 color => UNSIGNED1 code,STRING10 name});

OUTPUT('Red' IN InlineDCT); //true
InlineDCT['Red'].code;      //2
InlineDCT['Red'].name;      //Sue
InlineDCT['Red'];           //Red   2   Sue

//Form 2 examples -- parameter passing
MyDCTfunc(DICTIONARY({STRING10 color => UNSIGNED1 code,STRING10 name}) DCT,
          STRING10 key) := DCT[key].name;
MyDCTfunc(InlineDCT,'White');  //Jo
MyDCTfunc(DsDCT,'Brown');      //Seth