Package net.cscott.jutil

Record Class Pair<A,B>

java.lang.Object
java.lang.Record
net.cscott.jutil.Pair<A,B>
Type Parameters:
A - the type of the left element
B - the type of the right element
Record Components:
left - the left element of the pair (head)
right - the right element of the pair (tail)
All Implemented Interfaces:
Serializable
public record Pair<A,B>(A left, B right) extends Record implements Serializable
An immutable pair of values, either of which may be null. Two Pairs are equal when their left values are equal and their right values are equal, so pairs can be keys in hash tables. A Pair is serializable if its values are.

Pair replaces Default.PairList, which is a mutable List of two Objects. For a pair which is a Map.Entry, use PairMapEntry or AbstractMap.SimpleImmutableEntry.

Since:
2.0
Author:
C. Scott Ananian <cananian@alumni.princeton.edu>
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Pair(A left, B right)
    Creates an instance of a Pair record class.

  • Method Summary

    Modifier and Type
    Method
    Description
    final boolean
    equals(Object o)
    Indicates whether some other object is "equal to" this one.
    final int
    hashCode()
    Returns a hash code value for this object.
    A
    left()
    Returns the value of the left record component.
    B
    right()
    Returns the value of the right record component.
    final String
    toString()
    Returns a string representation of this record class.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Pair

      public Pair(A left, B right)
      Creates an instance of a Pair record class.
      Parameters:
      left - the value for the left record component
      right - the value for the right record component

  • Method Details

    • toString

      public final String toString()
      Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.
      Specified by:
      toString in class Record
      Returns:
      a string representation of this object

    • hashCode

      public final int hashCode()
      Returns a hash code value for this object. The value is derived from the hash code of each of the record components.
      Specified by:
      hashCode in class Record
      Returns:
      a hash code value for this object

    • equals

      public final boolean equals(Object o)
      Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).
      Specified by:
      equals in class Record
      Parameters:
      o - the object with which to compare
      Returns:
      true if this object is the same as the o argument; false otherwise.

    • left

      public A left()
      Returns the value of the left record component.
      Returns:
      the value of the left record component

    • right

      public B right()
      Returns the value of the right record component.
      Returns:
      the value of the right record component