Enum TernaryValue

java.lang.Object
java.lang.Enum<TernaryValue>
com.google.javascript.rhino.jstype.TernaryValue
All Implemented Interfaces:
Serializable, Comparable<TernaryValue>, java.lang.constant.Constable

public enum TernaryValue extends Enum<TernaryValue>

An enum for ternary logic. The TRUE and FALSE values are equivalent to typical booleans, and the UNKNOWN value plays the role of a placeholder, which can be either TRUE or FALSE.

A ternary value expression evaluates to TRUE or FALSE only if all replacements of UNKNOWN in this expression yield the same result. Therefore, the ternary logic coincides with typical Boolean logic if the UNKNOWN value is not present in an expression.

See Also:
  • Enum Constant Details

    • FALSE

      public static final TernaryValue FALSE
      false
    • TRUE

      public static final TernaryValue TRUE
      true
    • UNKNOWN

      public static final TernaryValue UNKNOWN
      unknown, it represents lack of knowledge about whether this value is true or false.
  • Method Details

    • values

      public static TernaryValue[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      Returns:
      an array containing the constants of this enum type, in the order they are declared
    • valueOf

      public static TernaryValue valueOf(String name)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null
    • and

      public abstract TernaryValue and(TernaryValue that)
      Gets the and of this and that.
    • not

      public abstract TernaryValue not()
      Gets the not of this.
    • or

      public abstract TernaryValue or(TernaryValue that)
      Gets the or of this and that.
    • xor

      public abstract TernaryValue xor(TernaryValue that)
      Gets the xor of this and that.
    • toBoolean

      public abstract boolean toBoolean(boolean unknown)
      Converts this ternary value to boolean. The #TRUE and #FALSE values are simply converted to true and false respectively, whilst the UNKNOWN is converted to the specified unknown value.
      Parameters:
      unknown - the boolean value to which the UNKNOWN value is converted
      Returns:
      return
           this == TRUE ? true :
           this == FALSE ? false :
           unknown
    • forBoolean

      public static TernaryValue forBoolean(boolean val)
      Gets the TernaryValue for the given boolean.