Why does EK9 care about operator placement (prefix vs suffix)?

  - $value       converts to String
  - $$value      converts to JSON
  - #? value     hashcode (NOT a length - use 'length' for that)
  - #< text      first element, e.g. first Character of a String (types that define #<, such as String and Bits; List does not)
  - #> text      last element (types that define #>, such as String and Bits)
  - ~ list       reverses a List; ~ on Bits or Boolean negates (Integer has no ~)
  - not active   boolean negation
  - abs number   absolute value
  - sqrt number  square root
  - length name  gets length

  - value?       checks if value is set (isSet)
  - number!      factorial (an expression, like '?')
  - counter++    increment, and counter-- decrement (statements only - E07950 inside an expression)

  text#<       WRONG: #< is prefix, use '#< text'
  value$       WRONG: $ is prefix, use '$value'
  ?value       WRONG: ? is suffix, use 'value?'

defines module qa.gettingstarted.operatorplacement

  defines program

    OperatorPlacementDemo()
      -> userName as String
      stdout <- Stdout()

      nameText <- $userName
      stdout.println(nameText)

      nameLength <- length userName
      stdout.println(`Length: ${nameLength}`)

      if userName?
        stdout.println("User name is set")

      nameText <- userName$

      nameText <- $userName

      if ?userName

      if userName?