//
// sketch of all-purpose conversion program
// prompts for what type of conversion, then number to convert
//

val CmPerInch = 2.54

def inchesToCm(inches : Double) : Double = inches * CmPerInch

def cmToInches(cm : Double) : Double = cm / CmPerInch

def getInputNumber() : Double = {
  println("enter a number to convert")
  readDouble
}

def repeatConversion() {

  println("enter 'i' for inches to cm, 'c' for cm to inches, 'q' to quit")

  val which = readChar

  if (which == 'q') { }
  else if (which == 'i') {
    println(inchesToCm(getInputNumber()) + " cm")
    repeatConversion()
  }
  else if (which == 'c') {
    println(cmToInches(getInputNumber()) + " inches")
    repeatConversion()
  }
  else {
    println("not a valid choice")
    repeatConversion()
  }
}

repeatConversion()