Package com.sun.tools.javac.code

Class Scope

java.lang.Object

com.sun.tools.javac.code.Scope

Direct Known Subclasses:

Scope.CompoundScope, Scope.DelegatedScope, Scope.ErrorScope, Scope.ImportScope

public class Scope
extends Object

A scope represents an area of visibility in a Java program. The Scope class is a container for symbols which provides efficient access to symbols given their names. Scopes are implemented as hash tables with "open addressing" and "double hashing". Scopes can be nested; the next field of a scope points to its next outer scope. Nested scopes can share their hash tables.

This is NOT part of any supported API. If you write code that depends on this, you do so at your own risk. This code and its internal interfaces are subject to change or deletion without notice.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Scope.CompoundScope A class scope adds capabilities to keep track of changes in related class scopes - this allows client to realize whether a class scope has changed, either directly (because a new member has been added/removed to this scope) or indirectly (i.e.
static class	Scope.DelegatedScope An empty scope, into which you can't place anything.
static class	Scope.Entry A class for scope entries.
static class	Scope.ErrorScope An error scope, for which the owner should be an error symbol.
static class	Scope.ImportScope
static interface	Scope.ScopeListener
static class	Scope.StarImportScope

Field Summary

Fields

Modifier and Type	Field and Description
Scope.Entry	elems A linear list that also contains all entries in reverse order of appearance (i.e later entries are pushed on top).
static Scope	emptyScope A value for the empty scope.
Scope	next Next enclosing scope (with whom this scope may share a hashtable)
Symbol	owner The scope's owner.

Constructor Summary

Constructors

Constructor and Description
Scope(Symbol owner) Construct a new scope, within scope next, with given owner, using a fresh table of length INITIAL_SIZE.

Method Summary

Modifier and Type	Method and Description
void	addScopeListener(Scope.ScopeListener sl)
boolean	anyMatch(Filter<Symbol> sf)
Scope	dup() Construct a fresh scope within this scope, with same owner, which shares its table with the outer scope.
Scope	dup(Symbol newOwner) Construct a fresh scope within this scope, with new owner, which shares its table with the outer scope.
Scope	dupUnshared() Construct a fresh scope within this scope, with same owner, with a new hash table, whose contents initially are those of the table of its outer scope.
void	enter(Symbol sym) Enter symbol sym in this scope.
void	enter(Symbol sym, Scope s)
void	enter(Symbol sym, Scope s, Scope origin, boolean staticallyImported) Enter symbol sym in this scope, but mark that it comes from given scope `s' accessed through `origin'.
void	enterIfAbsent(Symbol sym) Enter symbol sym in this scope if not already there.
Iterable<Symbol>	getElements()
Iterable<Symbol>	getElements(Filter<Symbol> sf)
Iterable<Symbol>	getElementsByName(Name name)
Iterable<Symbol>	getElementsByName(Name name, Filter<Symbol> sf)
boolean	includes(Symbol c) Given a class, is there already a class with same fully qualified name in this (import) scope?
Scope	leave() Remove all entries of this scope from its table, if shared with next.
Scope.Entry	lookup(Name name) Return the entry associated with given name, starting in this scope and proceeding outwards.
Scope.Entry	lookup(Name name, Filter<Symbol> sf)
void	remove(Symbol sym) Remove symbol from this scope.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

next

public Scope next

Next enclosing scope (with whom this scope may share a hashtable)

owner

public Symbol owner

The scope's owner.

elems

public Scope.Entry elems

A linear list that also contains all entries in reverse order of appearance (i.e later entries are pushed on top).

emptyScope

public static final Scope emptyScope

A value for the empty scope.

Constructor Detail

Scope

public Scope(Symbol owner)

Construct a new scope, within scope next, with given owner, using a fresh table of length INITIAL_SIZE.

Method Detail

dup

public Scope dup()

Construct a fresh scope within this scope, with same owner, which shares its table with the outer scope. Used in connection with method leave if scope access is stack-like in order to avoid allocation of fresh tables.

dup

public Scope dup(Symbol newOwner)

Construct a fresh scope within this scope, with new owner, which shares its table with the outer scope. Used in connection with method leave if scope access is stack-like in order to avoid allocation of fresh tables.

dupUnshared

public Scope dupUnshared()

Construct a fresh scope within this scope, with same owner, with a new hash table, whose contents initially are those of the table of its outer scope.

leave

public Scope leave()

Remove all entries of this scope from its table, if shared with next.

enter

public void enter(Symbol sym)

Enter symbol sym in this scope.

enter

public void enter(Symbol sym,
                  Scope s)

enter

public void enter(Symbol sym,
                  Scope s,
                  Scope origin,
                  boolean staticallyImported)

Enter symbol sym in this scope, but mark that it comes from given scope `s' accessed through `origin'. The last two arguments are only used in import scopes.

addScopeListener

public void addScopeListener(Scope.ScopeListener sl)

remove

public void remove(Symbol sym)

Remove symbol from this scope. Used when an inner class attribute tells us that the class isn't a package member.

enterIfAbsent

public void enterIfAbsent(Symbol sym)

Enter symbol sym in this scope if not already there.

includes

public boolean includes(Symbol c)

Given a class, is there already a class with same fully qualified name in this (import) scope?

lookup

public Scope.Entry lookup(Name name)

Return the entry associated with given name, starting in this scope and proceeding outwards. If no entry was found, return the sentinel, which is characterized by having a null in both its scope and sym fields, whereas both fields are non-null for regular entries.

lookup

public Scope.Entry lookup(Name name,
                          Filter<Symbol> sf)

anyMatch

public boolean anyMatch(Filter<Symbol> sf)

getElements

public Iterable<Symbol> getElements()

getElements

public Iterable<Symbol> getElements(Filter<Symbol> sf)

getElementsByName

public Iterable<Symbol> getElementsByName(Name name)

getElementsByName

public Iterable<Symbol> getElementsByName(Name name,
                                          Filter<Symbol> sf)

toString

public String toString()

Overrides:

toString in class Object