com.google.gwt.dev.js.ast

Class JsScope

java.lang.Object

com.google.gwt.dev.js.ast.JsScope

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

JsNestingScope, JsRootScope

public abstract class JsScope
extends Object
implements Serializable

A scope is a factory for creating and allocating JsNames. A JavaScript AST is built in terms of abstract name objects without worrying about obfuscation, keyword/identifier blacklisting, and so on.

Scopes are associated with JsFunctions, but the two are not equivalent. Functions have scopes, but a scope does not necessarily have an associated Function. Examples of this include the JsRootScope and synthetic scopes that might be created by a client.

Scopes can have parents to provide constraints when allocating actual identifiers for names. Specifically, names in child scopes are chosen such that they do not conflict with names in their parent scopes. The ultimate parent is usually the global scope (see JsProgram.getScope()), but parentless scopes are useful for managing names that are always accessed with a qualifier and could therefore never be confused with the global scope hierarchy.

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	JsScope(String description)

Method Summary

Modifier and Type	Method and Description
protected abstract void	addChild(JsScope child)
JsName	declareName(String ident) Gets a name object associated with the specified ident in this scope, creating it if necessary.
JsName	declareName(String ident, String shortIdent) Gets a name object associated with the specified ident in this scope, creating it if necessary.
JsName	declareUnobfuscatableName(String ident) Gets a name object associated with the specified ident in this scope, creating it if necessary, and makes it non obfuscatable.
protected abstract JsName	doCreateName(String ident, String shortIdent) Creates a new name in this scope.
JsName	findExistingName(String ident) Attempts to find the name object for the specified ident, searching in this scope, and if not found, in the parent scopes.
protected abstract JsName	findExistingNameNoRecurse(String ident) Attempts to find the name object for the specified ident, searching in this scope only.
JsName	findExistingUnobfuscatableName(String ident) Attempts to find an unobfuscatable name object for the specified ident, searching in this scope, and if not found, in the parent scopes.
abstract Iterable<JsName>	getAllNames() Returns an iterable for all the names defined by this scope.
abstract List<JsScope>	getChildren() Returns a list of this scope's child scopes.
String	getDescription() Returns the descriptive name.
abstract JsScope	getParent() Returns the parent scope of this scope, or null if this is the root scope.
String	toString()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode

Constructor Detail

JsScope

protected JsScope(String description)

Method Detail

declareName

public final JsName declareName(String ident)

Gets a name object associated with the specified ident in this scope, creating it if necessary.

Parameters:

ident - An identifier that is unique within this scope.

declareName

public final JsName declareName(String ident,
                                String shortIdent)

Gets a name object associated with the specified ident in this scope, creating it if necessary.

Parameters:

ident - An identifier that is unique within this scope.

shortIdent - A "pretty" name that does not have to be unique.

Throws:

IllegalArgumentException - if ident already exists in this scope but the requested short name does not match the existing short name.

declareUnobfuscatableName

public final JsName declareUnobfuscatableName(String ident)

Gets a name object associated with the specified ident in this scope, creating it if necessary, and makes it non obfuscatable.

Parameters:

ident - An identifier that is unique within this scope.

findExistingName

public final JsName findExistingName(String ident)

Attempts to find the name object for the specified ident, searching in this scope, and if not found, in the parent scopes.

Returns:

null if the identifier has no associated name

findExistingUnobfuscatableName

public final JsName findExistingUnobfuscatableName(String ident)

Attempts to find an unobfuscatable name object for the specified ident, searching in this scope, and if not found, in the parent scopes.

Returns:

null if the identifier has no associated name

getAllNames

public abstract Iterable<JsName> getAllNames()

Returns an iterable for all the names defined by this scope.

getChildren

public abstract List<JsScope> getChildren()

Returns a list of this scope's child scopes.

getDescription

public String getDescription()

Returns the descriptive name.

getParent

public abstract JsScope getParent()

Returns the parent scope of this scope, or null if this is the root scope.

toString

public final String toString()

Overrides:

toString in class Object

addChild

protected abstract void addChild(JsScope child)

doCreateName

protected abstract JsName doCreateName(String ident,
                                       String shortIdent)

Creates a new name in this scope.

findExistingNameNoRecurse

protected abstract JsName findExistingNameNoRecurse(String ident)

Attempts to find the name object for the specified ident, searching in this scope only.

Returns:

null if the identifier has no associated name