the idea is to have a while-loop with an else statement

while-else.scala

// what it tries to solve:
var cond = true
if(cond) {
  while(cond) {
    // do something
  }
}
else {
  // do something else
}

// implementation:
object While {
  def apply(condition: => Boolean)(f: => Unit) = new While(condition)(f)
}

class While private(cond: => Boolean)(f1: => Unit) {
  private val init = cond
  while(cond) f1
  
  def Else(f2: => Unit): Unit = if(!init) f2
}

// usage:
var c = true
While(c) {
  println("while is true")
  c = false
} Else {
  println("while is false")
}

// will print "while is true" if true, and "while is false" only when while is false initially
// some cons about this: brackets are mandatory, 
//                       and Else MUST come after the closing bracket, it cannot be on its own line