Scala example source code file (Boolean.scala)

This example Scala source code file (Boolean.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

anyval, anyvalcompanion, boolean, class

The Boolean.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2002-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

// DO NOT EDIT, CHANGES WILL BE LOST
// This auto-generated code can be modified in scala.tools.cmd.gen.
// Afterwards, running tools/codegen-anyvals regenerates this source file.

package scala

/** `Boolean` (equivalent to Java's `boolean` primitive type) is a
 *  subtype of [[scala.AnyVal]]. Instances of `Boolean` are not
 *  represented by an object in the underlying runtime system.
 *
 *  There is an implicit conversion from [[scala.Boolean]] => [[scala.runtime.RichBoolean]]
 *  which provides useful non-primitive operations.
 */
final abstract class Boolean private extends AnyVal {
  /** Negates a Boolean expression.
    *
    * - `!a` results in `false` if and only if `a` evaluates to `true` and
    * - `!a` results in `true` if and only if `a` evaluates to `false`.
    *
    * @return the negated expression
    */
  def unary_! : Boolean

  /** Compares two Boolean expressions and returns `true` if they evaluate to the same value.
    *
    * `a == b` returns `true` if and only if
    *  - `a` and `b` are `true` or
    *  - `a` and `b` are `false`.
    */
  def ==(x: Boolean): Boolean

  /**
    * Compares two Boolean expressions and returns `true` if they evaluate to a different value.
    *
    * `a != b` returns `true` if and only if
    *  - `a` is `true` and `b` is `false` or
    *  - `a` is `false` and `b` is `true`.
    */
  def !=(x: Boolean): Boolean

  /** Compares two Boolean expressions and returns `true` if one or both of them evaluate to true.
    *
    * `a || b` returns `true` if and only if
    *  - `a` is `true` or
    *  - `b` is `true` or
    *  - `a` and `b` are `true`.
    *
    * @note This method uses 'short-circuit' evaluation and
    *       behaves as if it was declared as `def ||(x: => Boolean): Boolean`.
    *       If `a` evaluates to `true`, `true` is returned without evaluating `b`.
    */
  def ||(x: Boolean): Boolean

  /** Compares two Boolean expressions and returns `true` if both of them evaluate to true.
    *
    * `a && b` returns `true` if and only if
    *  - `a` and `b` are `true`.
    *
    * @note This method uses 'short-circuit' evaluation and
    *       behaves as if it was declared as `def &&(x: => Boolean): Boolean`.
    *       If `a` evaluates to `false`, `false` is returned without evaluating `b`.
    */
  def &&(x: Boolean): Boolean

  // Compiler won't build with these seemingly more accurate signatures
  // def ||(x: => Boolean): Boolean
  // def &&(x: => Boolean): Boolean

  /** Compares two Boolean expressions and returns `true` if one or both of them evaluate to true.
    *
    * `a | b` returns `true` if and only if
    *  - `a` is `true` or
    *  - `b` is `true` or
    *  - `a` and `b` are `true`.
    *
    * @note This method evaluates both `a` and `b`, even if the result is already determined after evaluating `a`.
    */
  def |(x: Boolean): Boolean

  /** Compares two Boolean expressions and returns `true` if both of them evaluate to true.
    *
    * `a & b` returns `true` if and only if
    *  - `a` and `b` are `true`.
    *
    * @note This method evaluates both `a` and `b`, even if the result is already determined after evaluating `a`.
    */
  def &(x: Boolean): Boolean

  /** Compares two Boolean expressions and returns `true` if they evaluate to a different value.
    *
    * `a ^ b` returns `true` if and only if
    *  - `a` is `true` and `b` is `false` or
    *  - `a` is `false` and `b` is `true`.
    */
  def ^(x: Boolean): Boolean

  override def getClass(): Class[Boolean] = null
}

object Boolean extends AnyValCompanion {

  /** Transform a value type into a boxed reference type.
   *
   *  Runtime implementation determined by `scala.runtime.BoxesRunTime.boxToBoolean`. See [[https://github.com/scala/scala src/library/scala/runtime/BoxesRunTime.java]].
   *
   *  @param  x   the Boolean to be boxed
   *  @return     a java.lang.Boolean offering `x` as its underlying value.
   */
  def box(x: Boolean): java.lang.Boolean = java.lang.Boolean.valueOf(x)

  /** Transform a boxed type into a value type.  Note that this
   *  method is not typesafe: it accepts any Object, but will throw
   *  an exception if the argument is not a java.lang.Boolean.
   *
   *  Runtime implementation determined by `scala.runtime.BoxesRunTime.unboxToBoolean`. See [[https://github.com/scala/scala src/library/scala/runtime/BoxesRunTime.java]].
   *
   *  @param  x   the java.lang.Boolean to be unboxed.
   *  @throws     ClassCastException  if the argument is not a java.lang.Boolean
   *  @return     the Boolean resulting from calling booleanValue() on `x`
   */
  def unbox(x: java.lang.Object): Boolean = x.asInstanceOf[java.lang.Boolean].booleanValue()

  /** The String representation of the scala.Boolean companion object. */
  override def toString = "object scala.Boolean"

}