Scala example source code file (ThreeValues.scala)

This example Scala source code file (ThreeValues.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

boolean, byte, no, threevalue, threevalues, unknown, yes

The ThreeValues.scala Scala example source code

package scala
package reflect.internal.util

/** A simple three value type for booleans with an unknown value */
object ThreeValues {

  type ThreeValue = Byte

  final val YES = 1
  final val NO = -1
  final val UNKNOWN = 0

  def fromBoolean(b: Boolean): ThreeValue = if (b) YES else NO
  def toBoolean(x: ThreeValue): Boolean = x == YES
}