bayou.jtype

Class Wildcard

java.lang.Object

bayou.jtype.Wildcard

All Implemented Interfaces:

TypeArg

public final class Wildcard
extends Object
implements TypeArg

Wildcard.

A wildcard is a type argument, see TypeArg.

See static convenience methods for creating `Wildcard` objects.

Note: a wildcard is *not* a type.

See also article Capturing Wildcards

Constructor Summary

Constructors

Constructor and Description
Wildcard(ReferenceType<?> upperBound, ReferenceType<?> lowerBound) Create a wildcard with bounds.

Method Summary

Instance Methods
ReferenceType<?>	getUpperBound() Get the upper bound.
ReferenceType<?>	getLowerBound() Get the lower bound.
int	hashCode()
boolean	equals(Object obj) Whether this wildcard is equal to another wildcard.
String	toString(boolean full) A textual description of the wildcard.
String	toString() A textual description of the wildcard.
Static Methods
Wildcard	extends_(Class<?> upperBound) Create a wildcard with an upper bound.
Wildcard	extends_(ReferenceType<?> upperBound) Create a wildcard with an upper bound.
Wildcard	super_(Class<?> lowerBound) Create a wildcard with a lower bound.
Wildcard	super_(ReferenceType<?> lowerBound) Create a wildcard with a lower bound.
Wildcard	unbounded() Create an unbounded wildcard.

Methods inherited from class java.lang.Object

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

Constructor Detail

Wildcard

public Wildcard(ReferenceType<?> upperBound,
                ReferenceType<?> lowerBound)

Create a wildcard with bounds.

`upperBound` must be non-null; it can be the Object type.

`lowerBound` must be non-null; it can be the null type.

( Strictly according to JLS, syntactically, a wildcard is either upper bounded or lower bounded, but not both. That is, semantically, either the lower bound is null-type, or the upper bound is `Object`, or both. We do not enforce or require that property in our library. )

Method Detail

extends_

public static Wildcard extends_(Class<?> upperBound)

Create a wildcard with an upper bound.

This method is equivalent to extends_(ClassType.of(upperBound))

Example

     TypeArg V = Wildcard.extends_(Number.class);  //  ? extends Number
 

extends_

public static Wildcard extends_(ReferenceType<?> upperBound)

Create a wildcard with an upper bound.

The lower bound is the null type.

super_

public static Wildcard super_(Class<?> lowerBound)

Create a wildcard with a lower bound.

This method is equivalent to super_(ClassType.of(lowerBound))

Example

     TypeArg V = Wildcard.super_(Number.class);  //  ? super Number
 

super_

public static Wildcard super_(ReferenceType<?> lowerBound)

Create a wildcard with a lower bound.

The upper bound is the Object type.

unbounded

public static Wildcard unbounded()

Create an unbounded wildcard.

The upper bound is `Object`, and the lower bound is the null type.

Example

     ClassType.of(List.class, Wildcard.unbounded());  //  List<?>
 

getUpperBound

public ReferenceType<?> getUpperBound()

Get the upper bound.

getLowerBound

public ReferenceType<?> getLowerBound()

Get the lower bound.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Whether this wildcard is equal to another wildcard.

Two wildcards are equal if their bounds are equal.

Overrides:

equals in class Object

toString

public String toString(boolean full)

A textual description of the wildcard.

If `full==false`, simpler names are used for bound types.

Specified by:

toString in interface TypeArg

toString

public String toString()

A textual description of the wildcard.

This method is equivalent to toString(true).

Overrides:

toString in class Object