Package art.cutils.value

Class Pair<F,S>

java.lang.Object

art.cutils.value.Pair<F,S>

Type Parameters:

F - first value type

S - second value type

public final class Pair<F,S>
extends Object

A pair of values. Two heads are better than one—sometimes.

Since:

2.0

Author:

Bobai Kato

Method Summary

Modifier and Type	Method	Description
Pair<F,S>	clear()	Remove both values to null from the Pair.
Pair<F,S>	deleteFirst()	Reset the first value to null.
Pair<F,S>	deleteSecond()	Reset the second value to null.
static <F,S> @NotNull Pair<F,S>	empty()	Create and empty pair.
boolean	equals(Object o)
Pair<F,S>	first(F first)	Use to set the first value.
F	getFirst()	Returns the first value.
S	getSecond()	Returns the second value.
boolean	hasFirst()	Check Pair has the first value.
int	hashCode()
boolean	hasSecond()	Check Pair has the second value.
boolean	isEmpty()	Returns true if both values are null.
boolean	isNotEmpty()	Returns true if both values are not null.
boolean	notHasFirst()	Check Pair not have the first value.
boolean	notHasSecond()	Check Pair not have the second value.
static <F,S> @NotNull Pair<F,S>	of(F first, S second)	Creates a pair of values.
Pair<F,S>	second(S second)	Use to set the second value.
void	setFirstAndSecond(F first, S second)	Use to set the first and second values.
@NotNull Pair<S,F>	swap()	Swap the first and second values.
@NotNull String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

of

@Contract(value="_, _ -> new",
          pure=true)
@NotNull
public static <F,S> @NotNull Pair<F,S> of(F first,
                                                      S second)

Creates a pair of values.

Parameters:

first - first value, can be null.

second - second value, can be null.

Returns:

a pair of values

empty

@Contract(value=" -> new",
          pure=true)
@NotNull
public static <F,S> @NotNull Pair<F,S> empty()

Create and empty pair.

Type Parameters:

F - first value type

S - second value type

Returns:

new instance of empty pair

getFirst

@Contract(pure=true)
public F getFirst()

Returns the first value.

Returns:

the first value

first

@Contract(mutates="this")
public Pair<F,S> first(F first)

Use to set the first value.

Parameters:

first - first value

Returns:

current instance of Pair

setFirstAndSecond

@Contract(mutates="this")
public void setFirstAndSecond(F first,
                              S second)

Use to set the first and second values.

Parameters:

first - first value

second - second value

clear

public Pair<F,S> clear()

Remove both values to null from the Pair.

Returns:

current instance of Pair

deleteFirst

@Contract(mutates="this")
public Pair<F,S> deleteFirst()

Reset the first value to null.

Returns:

current instance of Pair

deleteSecond

@Contract(mutates="this")
public Pair<F,S> deleteSecond()

Reset the second value to null.

Returns:

current instance of Pair

getSecond

@Contract(pure=true)
public S getSecond()

Returns the second value.

Returns:

the second value

swap

@Contract(value=" -> new",
          pure=true)
@NotNull
public @NotNull Pair<S,F> swap()

Swap the first and second values.

Returns:

instance of Pair with swapped values

second

@Contract(mutates="this")
public Pair<F,S> second(S second)

Use to set the second value.

Parameters:

second - second value

Returns:

current instance of Pair

isNotEmpty

@Contract(pure=true)
public boolean isNotEmpty()

Returns true if both values are not null.

Returns:

true if both values are not null

isEmpty

@Contract(pure=true)
public boolean isEmpty()

Returns true if both values are null.

Returns:

true if both values are null

notHasFirst

@Contract(pure=true)
public boolean notHasFirst()

Check Pair not have the first value.

Returns:

true if Pair has no first value

hasFirst

@Contract(pure=true)
public boolean hasFirst()

Check Pair has the first value.

Returns:

true if Pair has first value

notHasSecond

@Contract(pure=true)
public boolean notHasSecond()

Check Pair not have the second value.

Returns:

true if Pair has no second value

hasSecond

@Contract(pure=true)
public boolean hasSecond()

Check Pair has the second value.

Returns:

true if Pair has second value

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

@Contract(value="null -> false",
          pure=true)
public boolean equals(Object o)

Overrides:

equals in class Object

toString

@Contract(pure=true)
@NotNull
public @NotNull String toString()

Overrides:

toString in class Object