Conditional

iff

To be used to determine whether another expression is true or false. If the expression is true, it returns one value; if it is false, it returns another.

 iff (expression, then, else)

case

Evaluates a list of conditions and returns one of the multiple possible result expressions. To provide multiple conditions must be used with iff.

null |case (conditions, else)

• conditions: list of conditions to be evaluated
• else: if no conditions are met, it returns this value

|case is a monadic operator in which the input of the monad has no effect on the result

Example:

null|case(iff(a==1, 'ok1'), 
          iff(a==2, 'ok2'),
          'nok')