Package org.organicdesign.fp.oneOf

Class OneOf4<A,B,C,D>

java.lang.Object

org.organicdesign.fp.oneOf.OneOf4<A,B,C,D>

public abstract class OneOf4<A,B,C,D>
extends Object

Holds one of 4 types of value. See OneOf2 for a full description.

Field Summary

Fields

Modifier and Type	Field	Description
protected @NotNull Object	item

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	OneOf4(@NotNull Object o, @NotNull Class<A> aClass, @NotNull Class<B> bClass, @NotNull Class<C> cClass, @NotNull Class<D> dClass, int index)	Protected constructor for subclassing.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)
int	hashCode()
<R> R	match(@NotNull Fn1<A,R> fa, @NotNull Fn1<B,R> fb, @NotNull Fn1<C,R> fc, @NotNull Fn1<D,R> fd)	Languages that have union types built in have a match statement that works like this method.
@NotNull String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

item

@NotNull
protected final @NotNull Object item

Constructor Detail

OneOf4

protected OneOf4(@NotNull
                 @NotNull Object o,
                 @NotNull
                 @NotNull Class<A> aClass,
                 @NotNull
                 @NotNull Class<B> bClass,
                 @NotNull
                 @NotNull Class<C> cClass,
                 @NotNull
                 @NotNull Class<D> dClass,
                 int index)

Protected constructor for subclassing.

Parameters:

o - the item

aClass - class 0

bClass - class 1

cClass - class 2

dClass - class 3

index - 0 means this represents an A, 1 a B, 2 a C, and 3 a D.

Method Detail

match

public <R> R match(@NotNull
                   @NotNull Fn1<A,R> fa,
                   @NotNull
                   @NotNull Fn1<B,R> fb,
                   @NotNull
                   @NotNull Fn1<C,R> fc,
                   @NotNull
                   @NotNull Fn1<D,R> fd)

Languages that have union types built in have a match statement that works like this method. Exactly one of these functions will be executed - determined by which type of item this object holds.

Parameters:

fa - applied iff this stores the first type.

fb - applied iff this stores the second type.

fc - applied iff this stores the third type.

fd - applied iff this stores the fourth type.

Returns:

the return value of whichever function is executed.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object

toString

@NotNull
public @NotNull String toString()

Overrides:

toString in class Object