Big-Data-HPC-Platform/initfiles/examples/ProgrammersGuide/SmartStepping2.ecl

//
//  Example code - use without restriction.  
//
Rec := RECORD,MAXLENGTH(4096)
	STRING1 Letter;
	UNSIGNED1 DS;
	UNSIGNED1 Matches := 0;
	UNSIGNED1 LastMatch := 0;
	SET OF UNSIGNED1 MatchDSs := [];
END;
ds1 := DATASET([{'A',1},{'B',1},{'C',1},{'D',1},{'E',1}],Rec);
ds2 := DATASET([{'A',2},{'B',2},{'H',2},{'I',2},{'J',2}],Rec);
ds3 := DATASET([{'B',3},{'C',3},{'M',3},{'N',3},{'O',3}],Rec);
ds4 := DATASET([{'A',4},{'B',4},{'R',4},{'S',4},{'T',4}],Rec);
ds5 := DATASET([{'B',5},{'V',5},{'W',5},{'X',5},{'Y',5}],Rec);

SetDS := [ds1,ds2,ds3,ds4,ds5];

Rec XF(Rec L,DATASET(Rec) Matches) := TRANSFORM
	SELF.Matches := COUNT(Matches);
	SELF.LastMatch := MAX(Matches,DS);
	SELF.MatchDSs := SET(Matches,DS);
	SELF := L;
END;
j1 := JOIN( SetDS,STEPPED(LEFT.Letter=RIGHT.Letter),XF(LEFT,ROWS(LEFT)),SORTED(Letter));

O1 := OUTPUT(j1);

Rec XF1(Rec L,Rec R,integer MatchSet) := TRANSFORM
  SELF.Matches := L.Matches + 1;
  SELF.LastMatch := MatchSet;
  SELF.MatchDSs := L.MatchDSs + [MatchSet];
  SELF := L;
END;
j2 := JOIN( ds1,ds2,LEFT.Letter=RIGHT.Letter,XF1(LEFT,RIGHT,2));
j3 := JOIN( j2,ds3, LEFT.Letter=RIGHT.Letter,XF1(LEFT,RIGHT,3));
j4 := JOIN( j3,ds4, LEFT.Letter=RIGHT.Letter,XF1(LEFT,RIGHT,4));
j5 := JOIN( j4,ds5, LEFT.Letter=RIGHT.Letter,XF1(LEFT,RIGHT,5));
O2 := OUTPUT(SORT(j5,Letter));

j6 := JOIN( SetDS,STEPPED(LEFT.Letter=RIGHT.Letter),XF(LEFT,ROWS(LEFT)),SORTED(Letter),LEFT OUTER);
j7 := JOIN( SetDS,STEPPED(LEFT.Letter=RIGHT.Letter),XF(LEFT,ROWS(LEFT)),SORTED(Letter),LEFT ONLY);
j8 := JOIN( SetDS,STEPPED(LEFT.Letter=RIGHT.Letter),XF(LEFT,ROWS(LEFT)),SORTED(Letter),MOFN(3));
j9 := JOIN( SetDS,STEPPED(LEFT.Letter=RIGHT.Letter),XF(LEFT,ROWS(LEFT)),SORTED(Letter),MOFN(3,4));
O3 := OUTPUT(j6);
O4 := OUTPUT(j7);
O5 := OUTPUT(j8);
O6 := OUTPUT(j9);

j10 := JOIN( RANGE(SetDS,[1,3,5]),STEPPED(LEFT.Letter=RIGHT.Letter),XF(LEFT,ROWS(LEFT)),SORTED(Letter));
O7 := OUTPUT(j10);

SEQUENTIAL(O1,O2,O3,O4,O5,O6,O7);