Class Scope

java.lang.Object

org.inferred.freebuilder.processor.source.Scope

Direct Known Subclasses:

CompilationUnitBuilder.InitialScope, Scope.FileScope, Scope.MethodScope

public abstract class Scope
extends Object

An append-only, hierarchical map with key-specific value typing.

Scopes allow source generators to cooperate with each other—to avoid namespace clashes or reuse variables, for example—in a decoupled fashion using a shared key-value space. The key type dictates the type of the value that can be stored in the map, as well as at what level in the source the key should be unique at: FILE keys are unique within a compilation unit, while METHOD keys are scoped to the current method.

While a Scope has to be mutable, it limits the potential for complex bugs by only permitting key-values pairs to be inserted, not modified or removed.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	Scope.FileScope
static interface	Scope.Key<V>
static enum	Scope.Level
(package private) static class	Scope.MethodScope

Field Summary

Fields

Modifier and Type	Field	Description
private final Map<Scope.Key<?>, Object>	entries
private final Scope	parent
private static final Object	RECURSION_SENTINEL

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Scope()
protected	Scope(Scope parent)

Method Summary

Modifier and Type	Method	Description
protected abstract boolean	canStore(Scope.Key<?> key)
<V> V	computeIfAbsent(Scope.Key<V> key, Supplier<V> supplier)	If key is not already associated with a value, computes its value using supplier and enters it into the scope.
boolean	contains(Scope.Key<?> key)
<V> V	get(Scope.Key<V> key)
boolean	isEmpty()
<V> Set<V>	keysOfType(Class<V> keyType)
<V> V	putIfAbsent(Scope.Key<V> key, V value)	If key is not already associated with a value, associates it with value.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

RECURSION_SENTINEL

private static final Object RECURSION_SENTINEL

entries

private final Map<Scope.Key<?>, Object> entries

parent

private final Scope parent

Constructor Details

Scope

protected Scope()

Scope

protected Scope(Scope parent)

Method Details

canStore

protected abstract boolean canStore(Scope.Key<?> key)

isEmpty

public boolean isEmpty()

contains

public boolean contains(Scope.Key<?> key)

get

public <V> V get(Scope.Key<V> key)

computeIfAbsent

public <V> V computeIfAbsent(Scope.Key<V> key,
 Supplier<V> supplier)

If key is not already associated with a value, computes its value using supplier and enters it into the scope.

Returns:

the current (existing or computed) value associated with key

keysOfType

public <V> Set<V> keysOfType(Class<V> keyType)

putIfAbsent

public <V> V putIfAbsent(Scope.Key<V> key,
 V value)

If key is not already associated with a value, associates it with value.

Returns:

the original value, or null if there was no value associated