Package com.google.javascript.jscomp

Class NodeTraversal

java.lang.Object

com.google.javascript.jscomp.NodeTraversal

public class NodeTraversal
extends java.lang.Object

NodeTraversal allows an iteration through the nodes in the parse tree, and facilitates the optimizations on the parse tree.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	NodeTraversal.AbstractCfgCallback	An traversal base class that tracks and caches the ControlFlowGraph (CFG) during the traversal.
static class	NodeTraversal.AbstractChangedScopeCallback	Callback that fires on changed scopes.
static class	NodeTraversal.AbstractModuleCallback	Abstract callback that knows when a global script, goog.provide file, goog.module, goog.loadModule, ES module or CommonJS module is entered or exited.
static class	NodeTraversal.AbstractPostOrderCallback	Abstract callback to visit all nodes in postorder.
static interface	NodeTraversal.AbstractPostOrderCallbackInterface	Abstract callback to visit all nodes in postorder.
static class	NodeTraversal.AbstractPreOrderCallback	Abstract callback to visit all nodes in preorder.
static class	NodeTraversal.AbstractScopedCallback	Abstract scoped callback to visit all nodes in postorder.
static class	NodeTraversal.AbstractShallowCallback	Abstract callback to visit all nodes but not traverse into function bodies.
static class	NodeTraversal.AbstractShallowStatementCallback	Abstract callback to visit all structure and statement nodes but doesn't traverse into functions or expressions.
static class	NodeTraversal.Builder	Builder
static interface	NodeTraversal.Callback	Callback for tree-based traversals
static class	NodeTraversal.ExternsSkippingCallback	Abstract callback to visit all non-extern nodes in postorder.
static interface	NodeTraversal.ScopedCallback	Callback that also knows about scope changes

Method Summary

Modifier and Type	Method	Description
static NodeTraversal.Builder	builder()
AbstractScope<?,?>	getAbstractScope()	Gets the current scope.
@Nullable JSChunk	getChunk()	Gets the current input chunk.
@Nullable AbstractScope<?,?>	getClosestContainerScope()
@Nullable AbstractScope<?,?>	getClosestHoistScope()
@Nullable Node	getClosestHoistScopeRoot()
AbstractCompiler	getCompiler()
Node	getCurrentNode()	Returns the node currently being traversed.
@Nullable Node	getEnclosingFunction()	Examines the functions stack for the last instance of a function node.
CompilerInput	getInput()	Gets the current input source.
Scope	getScope()
com.google.javascript.jscomp.ScopeCreator	getScopeCreator()
@Nullable Node	getScopeRoot()	Returns the current scope's root.
java.lang.String	getSourceName()	Gets the current input source name.
TypedScope	getTypedScope()
boolean	inFunctionBlockScope()	Determines whether the traversal is currently in the scope of the block of a function.
boolean	inGlobalHoistScope()	Determines whether the hoist scope of the current traversal is global.
boolean	inGlobalOrModuleScope()
boolean	inGlobalScope()	Determines whether the traversal is currently in the global scope.
boolean	inModuleHoistScope()	Determines whether the hoist scope of the current traversal is global.
boolean	inModuleScope()	Determines whether the traversal is currently in a module scope.
boolean	isHoistScope()
void	report(Node n, DiagnosticType diagnosticType, java.lang.String... arguments)	Reports a diagnostic (error or warning)
void	reportCodeChange()
void	reportCodeChange(Node n)
static void	traverse(AbstractCompiler compiler, Node root, NodeTraversal.Callback cb)	Traverses using the SyntacticScopeCreator
static void	traverseRoots(AbstractCompiler compiler, NodeTraversal.Callback cb, Node externs, Node root)
static void	traverseScopeRoots(AbstractCompiler compiler, @Nullable Node root, @Nullable java.util.List<Node> scopeNodes, NodeTraversal.Callback cb, boolean traverseNested)	Traverses *just* the contents of provided scope nodes (and optionally scopes nested within them) but will fall back on traversing the entire AST from root if a null scope nodes list is provided.

Methods inherited from class java.lang.Object

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

Method Detail

builder

public static NodeTraversal.Builder builder()

traverse

public static void traverse(AbstractCompiler compiler,
                            Node root,
                            NodeTraversal.Callback cb)

Traverses using the SyntacticScopeCreator

traverseRoots

public static void traverseRoots(AbstractCompiler compiler,
                                 NodeTraversal.Callback cb,
                                 Node externs,
                                 Node root)

traverseScopeRoots

public static void traverseScopeRoots(AbstractCompiler compiler,
                                      @Nullable Node root,
                                      @Nullable java.util.List<Node> scopeNodes,
                                      NodeTraversal.Callback cb,
                                      boolean traverseNested)

Traverses *just* the contents of provided scope nodes (and optionally scopes nested within them) but will fall back on traversing the entire AST from root if a null scope nodes list is provided.

Parameters:

root - If scopeNodes is null, this method will just traverse 'root' instead. If scopeNodes is not null, this parameter is ignored.

getCompiler

public AbstractCompiler getCompiler()

getSourceName

public java.lang.String getSourceName()

Gets the current input source name.

Returns:

A string that may be empty, but not null

getInput

public CompilerInput getInput()

Gets the current input source.

getChunk

public @Nullable JSChunk getChunk()

Gets the current input chunk.

getCurrentNode

public Node getCurrentNode()

Returns the node currently being traversed.

getEnclosingFunction

public @Nullable Node getEnclosingFunction()

Examines the functions stack for the last instance of a function node. When possible, prefer this method over NodeUtil.getEnclosingFunction() because this in general looks at less nodes.

getScopeRoot

public @Nullable Node getScopeRoot()

Returns the current scope's root.

getScope

public Scope getScope()

getTypedScope

public TypedScope getTypedScope()

getAbstractScope

public AbstractScope<?,?> getAbstractScope()

Gets the current scope.

isHoistScope

public boolean isHoistScope()

getClosestHoistScopeRoot

public @Nullable Node getClosestHoistScopeRoot()

getClosestContainerScope

public @Nullable AbstractScope<?,?> getClosestContainerScope()

getClosestHoistScope

public @Nullable AbstractScope<?,?> getClosestHoistScope()

getScopeCreator

public com.google.javascript.jscomp.ScopeCreator getScopeCreator()

inGlobalScope

public boolean inGlobalScope()

Determines whether the traversal is currently in the global scope. Note that this returns false in a global block scope.

inModuleScope

public boolean inModuleScope()

Determines whether the traversal is currently in a module scope.

inGlobalOrModuleScope

public boolean inGlobalOrModuleScope()

inFunctionBlockScope

public boolean inFunctionBlockScope()

Determines whether the traversal is currently in the scope of the block of a function.

inGlobalHoistScope

public boolean inGlobalHoistScope()

Determines whether the hoist scope of the current traversal is global.

inModuleHoistScope

public boolean inModuleHoistScope()

Determines whether the hoist scope of the current traversal is global.

report

public void report(Node n,
                   DiagnosticType diagnosticType,
                   java.lang.String... arguments)

Reports a diagnostic (error or warning)

reportCodeChange

public void reportCodeChange()

reportCodeChange

public void reportCodeChange(Node n)