Record Class Scope

java.lang.Object

java.lang.Record

org.microbean.scope.Scope

Record Components:

id - a non-null Attributes identifying this Scope

normal - whether this Scope is normal

All Implemented Interfaces:

Constable

public record Scope(Attributes id, boolean normal)
extends Record
implements Constable

A representation of the defining characteristics of a scope, a logical entity that manages the lifecycle of objects.

A Scope is either a normal scope or a pseudo-scope. Implementations of normal scopes permit their objects to have circular dependencies, whereas pseudo-scopes do not. Pragmatically, objects managed by normal scopes are usually instances of a particular kind of proxy, namely a client proxy. Objects managed by pseudo-scopes may or may not be proxied, but are not client proxies.

A Scope is notionally governed by another scope which manages its lifecycle. A Scope that reports that it is governed by itself is known as the primordial scope. All scopes are ultimately governed by the primordial scope.

In any program using Scopes, behavior is undefined if there exist two Scopes with equal identifiers but any other differing attributes. Any collection of Scopes, in other words, must be a set.

Behavior is also undefined if any two scopes declare each other, by any means, as their respective governing scopes.

Author:

Laird Nelson

Field Summary

Fields

Modifier and Type	Field	Description
static final Scope	APPLICATION	The (well-known and normal) application scope.
static final Attributes	APPLICATION_ID	An Attributes identifying the (well-known and normal) application scope.
static final Scope	NONE	The (well-known) none pseudo-scope.
static final Attributes	NONE_ID	AnAttributes identifying the (well-known) none pseudo-scope.
static final Attributes	SCOPE	An Attributes identifying the scope designator.
static final Scope	SINGLETON	The (well-known and primordial) singleton pseudo-scope.
static final Attributes	SINGLETON_ID	An Attributes identifying the (well-known) singleton pseudo-scope.

Constructor Summary

Constructors

Constructor	Description
Scope(Attributes id, boolean normal)	Creates a new Scope.

Method Summary

Modifier and Type	Method	Description
final Optional<? extends ConstantDesc>	describeConstable()	Returns a non-null Optional housing a ConstantDesc describing this Scope, or an empty Optional if this Scope could not be so described.
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.
Attributes	id()	Returns the value of the id record component.
boolean	normal()	Returns the value of the normal record component.
static final Scope	of(Attributes id, boolean normal)	Returns a Scope suitable for the supplied arguments.
static final Attributes	scope()	Returns the scope designator.
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

Field Details

SCOPE

public static final Attributes SCOPE

An Attributes identifying the scope designator.

SINGLETON_ID

public static final Attributes SINGLETON_ID

An Attributes identifying the (well-known) singleton pseudo-scope.

The Attributes constituting the singleton pseudo-scope identifier is attributed with the scope designator, the qualifier designator, and the primordial qualifier, indicating that the scope it identifies governs itself.

See Also:

• SINGLETON

SINGLETON

public static final Scope SINGLETON

The (well-known and primordial) singleton pseudo-scope.

See Also:

• SINGLETON_ID

APPLICATION_ID

public static final Attributes APPLICATION_ID

An Attributes identifying the (well-known and normal) application scope.

See Also:

• APPLICATION

APPLICATION

public static final Scope APPLICATION

The (well-known and normal) application scope.

See Also:

• APPLICATION_ID

NONE_ID

public static final Attributes NONE_ID

AnAttributes identifying the (well-known) none pseudo-scope.

See Also:

• NONE

NONE

public static final Scope NONE

The (well-known) none pseudo-scope.

See Also:

• NONE_ID

Constructor Details

Scope

public Scope(Attributes id,
 boolean normal)

Creates a new Scope.

Parameters:

id - a non-null Attributes identifying this Scope; must be a scope

normal - whether this Scope is normal

Throws:

NullPointerException - if any argument is null

IllegalArgumentException - if any argument is not a scope

See Also:

• of(Attributes, boolean)

Method Details

describeConstable

public final Optional<? extends ConstantDesc> describeConstable()

Returns a non-null Optional housing a ConstantDesc describing this Scope, or an empty Optional if this Scope could not be so described.

Specified by:

describeConstable in interface Constable

Returns:

a non-null Optional

of

public static final Scope of(Attributes id,
 boolean normal)

Returns a Scope suitable for the supplied arguments.

Parameters:

id - a non-null Attributes identifying this Scope

normal - whether this Scope is normal

Returns:

a non-null Scope

Throws:

NullPointerException - if any argument is null

scope

public static final Attributes scope()

Returns the scope designator.

Returns:

a non-null Attributes

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. Reference components are compared with Objects::equals(Object,Object); primitive components are compared with the compare method from their corresponding wrapper classes.

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.

id

public Attributes id()

Returns the value of the id record component.

Returns:

the value of the id record component

normal

public boolean normal()

Returns the value of the normal record component.

Returns:

the value of the normal record component