Proposal: Add functions to generate random values

[jhorbulyk]

It would be nice if JSONata had the ability to generate random values. Consider the following two cases:

• Generate a random number between 0 and 1 (similar to Math.random() in JavaScript.)
• Generate a random GUID/UUID. (Harder to do without pulling in something like uuid as a dependency.)

[andrew-coleman]

We can do the first one already - https://docs.jsonata.org/numeric-functions#random

[markmelville]

I looked at some of the javascript implementations for uuid and worked out this expression that generates a v4 UUID:

(
  $binPad:=function($n, $len){$pad($formatBase($n,2),-$len,'0')};
  $bitwise:=function($lb, $rb, $fn){$split($lb,'')~>$map(function($c, $i){$fn($c='1',$substring($rb,$i,1)='1')?$power(2,(7-$i)):0})~>$sum()};
  $and:=function($l,$r){$bitwise($binPad($l,8),$binPad($r,8),function($1,$2){$1 and $2})};
  $or:=function($l,$r){$bitwise($binPad($l,8),$binPad($r,8),function($1,$2){$1 or $2})};  
  [0..15]~>$map(function(){$floor($random()*256)})
    ~>$map(function($v,$i){$i=6?$or($and($v,15),64):$i=8?$or($and($v,63),128):$v})
    ~>$map(function($n,$i){$pad($formatBase($n,16),-2,'0') & ($i in [3,5,7,9]?'-':'')})
    ~>$join()
)

What would have made this simpler is if there were bitwise operators built-in to Jsonata, but that should be a separate request, I suppose.

[zubairov]

Though issue with random solved I strongly believe the $uuid() will be a beneficial addition to JSONata

[adamgins]

HI does any one have an example where would adjust above not to be HEX, I am actually just looking for a random set of characters?

update: I just made something like

(
  $charSet := ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" ,"!","-"];  
  $randomChar := function(){
      (
          $randomCharChosen := $floor($random()* $count($charSet));
          $charSet[$randomCharChosen];
           

      )
      };
 
$reduce([0..10],function($v,$i){( $v & $randomChar();)})

)

[dubnemo]

Though issue with random solved I strongly believe the $uuid() will be a beneficial addition to JSONata

It seems there isn't a separate issue related to UUID() and it seems like there is consensus. I need it inside a map, to generate a new one as I iterate through an array.