ghadishayban

package demo
  
class Coder(words: List[String]) {

  private val mnemonics = Map(
      '2' -> "ABC", '3' -> "DEF", '4' -> "GHI", '5' -> "JKL", 
      '6' -> "MNO", '7' -> "PQRS", '8' -> "TUV", '9' -> "WXYZ")
      
  private val charCode: Map[Char, Char] = 
    for ((digit, str) <- mnemonics; letter <- str) yield letter -> digit