my code is disclosed above

Upd: 67

Upd: 72

Fixed bugs/typos and added new types.

#include %PVA
types ; Show COS-Datatypes ; kav ; 2018-03-04
 n array,i,bitstring
 
 s $bit(bitstring,1) = 1

 w "№",?4,"VALUE",?30,"JSON",?45,"$LISTBUILD",!,$TR($J("",55)," ","-"),!
 
 s array=[
          (bitstring),
          ($ZBITSET($ZBITSTR(4,1),2,0)),
          ($lb("")),
          null,
          true,
          false,
          (##class(%ZEN.proxyObject).%New()),
          [],
          {},
          "abcd",
          ($wc(35222)),
          "2",
          2,
          -2,
          2.1,
          -2.1,
          ($double(2.1))
          ]
 s array."18"=2
 s array."19"=-2
          
 f i=0:1:array.%Size() {
   w i,")",?4,array.%Get(i),?30,$$TypeOf1(.array,i),?45,$$TypeOf2(array.%Get(i)),!
 }
 
 // Return JSON datatype by the documented way
 //
TypeOf1(&array,key)
{
  s typ=array.%GetTypeCodeOf(key)
  q typ_" "_$case(typ,
    $$$PVVALUENULL:"null",
    $$$PVVALUETRUE:"boolTrue",
    $$$PVVALUEFALSE:"boolFalse",
    $$$PVVALUEINTEGERPOS:"+int",
    $$$PVVALUEINTEGERNEG:"-int",
    $$$PVVALUEUNUSED1:"unused",
    $$$PVVALUEARRAY:"array",
    $$$PVVALUEOBJECT:"object",
    $$$PVVALUETEXT:"text",
    $$$PVVALUENUMBER:"number",
    $$$PVVALUEOVERFLOW:"overflow",
    $$$PVVALUECACHENUMERIC:"cacheNumeric",
    $$$PVVALUEOREF:"oref",
    $$$PVVALUEUNASSIGNED:"unassigned",
    $$$PVVALUELONGPOS:"+long",
    $$$PVVALUELONGNEG:"-long",
    $$$PVVALUEBYTE:"byte[]",
    $$$PVVALUEDATETIME:"dateTime",
    $$$PVVALUEDOUBLE:"double",
    $$$PVVALUESINGLE:"single",
    $$$PVVALUEUTF8:"utf8",
    $$$PVVALUENESTED:"nested",
    $$$PVVALUEEOF:"eof",
    :"unknown")
}
   
 // Return datatype by the undocumented $LB() way
 //
TypeOf2(val)
 {
  i $l(val)>253 {
    s typ=$ziswide(val)+1
  } else {
    s typ=$a($lb(val),2)
  }
  q typ_" "_$case(typ
    ,1:"8bitString"
    ,2:"16bitString"
    ,4:"nonNegativeInteger"
    ,5:"negativeInteger"
    ,6:"nonNegativeFloat"
    ,7:"negativeFloat"
    ,8:"double"
    , :"??? never seen before")
}

Result:

USER>d ^types
№   VALUE                     JSON           $LISTBUILD
-------------------------------------------------------
0)  Ÿ                          8 text         1 8bitString
                              8 text         1 8bitString
2)                            8 text         1 8bitString
3)                            0 null         1 8bitString
4)  1                         1 boolTrue     1 8bitString
5)  0                         2 boolFalse    1 8bitString
6)  4@%ZEN.proxyObject        12 oref        1 8bitString
7)  2@%Library.DynamicArray   6 array        1 8bitString
8)  1@%Library.DynamicObject  7 object       1 8bitString
9)  abcd                      8 text         1 8bitString
10) 視                         8 text         2 16bitString
11) 2                         8 text         1 8bitString
12) 2                         9 number       4 nonNegativeInteger
13) -2                        9 number       5 negativeInteger
14) 2.1                       9 number       6 nonNegativeFloat
15) -2.1                      9 number       7 negativeFloat
16) 2.1000000000000000888     18 double      8 double
17)                           13 unassigned  1 8bitString
18) 2                         3 +int         4 nonNegativeInteger
19) -2                        4 -int         5 negativeInteger
20)                           31 eof         1 8bitString

On my desktop quite other results.

  n N,j,time

  s N=1e8

  f j=1,2/*,3,4,5*/ {
    w j,") "

    s time=$zh
    d @("j"_j)(N)
    w $zh-time," s.",!
  }
  q
j1(N) public {
  f i=1:1:N {s (a,b,c,d,e,f)=0}
}
j2(N) public {
  f i=1:1:N {s a=0,b=0,c=0,d=0,e=0,f=0}
}
j3(N) public {
  f i=1:1:N {s a=0,b=1,c=2,d=3,e=4,f=5}
}
j4(N) public {
  f i=1:1:N {s a=0 s b=1 s c=2 s d=3 s e=4 s f=5}
}
j5(N) public {
  f i=1:1:N {s $lb(a,b,c,d,e,f)=$lb(0,1,2,3,4,5)}
}

Results:

USER>d ^perf
1) 11.814189 s.
2) 4.683832 s.

As you can see the difference is almost 2.5 times.

I also want to note that
s (a,b,c)=0
is slower than
s a=0,b=0,c=0

Please note that the option with %INLIST does not yet use “collection” indexes, and will therefore be slower than the one provided above ^proof

Using Caché System Monitor

You are right, the macro $$$NULL present only in %sqlMigration.inc and this is not the file that developers often include to its project.
I prefer to use the macro $$$NULLOREF/$$$NULLOID from %occExtent.inc, which is available by default in the class that inherits from %Library.Base, and for routines is enough to include %systemInclude.inc.

Why so difficult?
This similarly following condition:

WHERE 
(
year(current_date) - year(DOB)
) >= 13

It Besides above was already indicated, why does not follow to use such a code, for example:

select datediff(year,
todate(to_char({d '1990-12-31'},'YYYY')||':1','YYYY:MM'), -- birthday
todate(to_char({d '2003-01-01'},'YYYY')||':1','YYYY:MM') -- report date
)

This gives an incorrect result - 13, although it should be 12.

The key difference of $classmethod is runtime:

$CLASSMETHOD permits a ObjectScript program to invoke an arbitrary class method in an arbitrary class. Both the class name and the method name may be computed at runtime or supplied as string constants.^proof

Class include is not required (and does not seem to affect anything) and can be omitted

Yeah, I just forgot to delete that line.

Then this:

Include Child

Class Macro.Child Extends Macro.Parent
{

ClassMethod first()
{
  #include Child
}

ClassMethod Test() [ PlaceAfter = first ]
{
  write "Class: " , $classname() , ! , "Value: " , $$$name
}

}

or this:

ClassMethod Test()
{
  #include Child
  write "Class: " , $classname() , ! , "Value: " , $$$name
}

Macro.Parent.cls:

Include Parent

Class Macro.Parent
{

ClassMethod Test()
{
  write "Class: " , $classname() , ! , "Value: " , $$$name 
}

}

Macro.Child.cls:

Include Child

Class Macro.Child Extends Macro.Parent
{

ClassMethod Test()
{
  write "Class: " , $classname() , ! , "Value: " , $$$name 
}

}

Parent.inc:

#ifndef name
  #define name "Parent"
#endif name

Child.inc:

#define name "Child"

Result:

>do ##class(Macro.Parent).Test()
Class: Macro.Parent
Value: Parent
>do ##class(Macro.Child).Test()
Class: Macro.Child
Value: Child

This data is saved in the registry. You can even save greater value than allowed by the program (see screenshot).

Example of work with the registry directly from Caché Object Script can be found here.

For better performance you should make a few changes:

1. add an index on DOB field
2. rebuild the index and run TuneTable
3. modify the query
   

   select DOB from HSAA.Patient
   where
   dob<=dateadd('yy',-13,current_date)
   or dob between
         todate((year(current_date)-13)||'0101','yyyymmdd')
     and todate((year(current_date)-13)||'1231','yyyymmdd')

The result will pleasantly surprise you.