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.AbstractNodeTypePruningCallback	Abstract callback to visit a pruned set of nodes.
static class	NodeTraversal.AbstractPostOrderCallback	Abstract callback to visit all nodes in post order.
static class	NodeTraversal.AbstractScopedCallback	Abstract scoped callback to visit all nodes in post order.
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 interface	NodeTraversal.Callback	Callback
static interface	NodeTraversal.ScopedCallback	Callback that also knows about scope changes

Field Summary

Fields

Modifier and Type	Field	Description
static DiagnosticType	NODE_TRAVERSAL_ERROR

Constructor Summary

Constructors

Constructor	Description
NodeTraversal(AbstractCompiler compiler, NodeTraversal.Callback cb)	Creates a node traversal using the specified callback interface.
NodeTraversal(AbstractCompiler compiler, NodeTraversal.Callback cb, com.google.javascript.jscomp.ScopeCreator scopeCreator)	Creates a node traversal using the specified callback interface and the scope creator.

Method Summary

Modifier and Type	Method	Description
Compiler	getCompiler()	Gets the compiler.
com.google.javascript.jscomp.ControlFlowGraph<Node>	getControlFlowGraph()	Gets the control flow graph for the current JS scope.
Node	getCurrentNode()	Returns the node currently being traversed.
Node	getEnclosingFunction()	Examines the functions stack for the last instance of a function node.
CompilerInput	getInput()	Gets the current input source.
int	getLineNumber()	Gets the current line number, or zero if it cannot be determined.
JSModule	getModule()	Gets the current input module.
Scope	getScope()	Gets the current scope.
Node	getScopeRoot()	Returns the current scope's root.
java.lang.String	getSourceName()	Gets the current input source name.
boolean	hasScope()
JSError	makeError(Node n, CheckLevel level, DiagnosticType type, java.lang.String... arguments)	Creates a JSError during NodeTraversal.
JSError	makeError(Node n, DiagnosticType type, java.lang.String... arguments)	Creates a JSError during NodeTraversal.
void	report(Node n, DiagnosticType diagnosticType, java.lang.String... arguments)	Reports a diagnostic (error or warning)
static void	traverse(AbstractCompiler compiler, Node root, NodeTraversal.Callback cb)	Traverses a node recursively.
void	traverse(Node root)	Traverses a parse tree recursively.
protected void	traverseInnerNode(Node node, Node parent, Scope refinedScope)	Traverses an inner node recursively with a refined scope.
static void	traverseRoots(AbstractCompiler compiler, NodeTraversal.Callback cb, Node... roots)
static void	traverseRoots(AbstractCompiler compiler, java.util.List<Node> roots, NodeTraversal.Callback cb)	Traverses a list of node trees.
void	traverseRoots(Node... roots)
void	traverseRoots(java.util.List<Node> roots)

Methods inherited from class java.lang.Object

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

Field Detail

NODE_TRAVERSAL_ERROR

public static final DiagnosticType NODE_TRAVERSAL_ERROR

Constructor Detail

NodeTraversal

public NodeTraversal(AbstractCompiler compiler,
                     NodeTraversal.Callback cb)

Creates a node traversal using the specified callback interface.

NodeTraversal

public NodeTraversal(AbstractCompiler compiler,
                     NodeTraversal.Callback cb,
                     com.google.javascript.jscomp.ScopeCreator scopeCreator)

Creates a node traversal using the specified callback interface and the scope creator.

Method Detail

traverse

public void traverse(Node root)

Traverses a parse tree recursively.

traverseRoots

public void traverseRoots(Node... roots)

traverseRoots

public void traverseRoots(java.util.List<Node> roots)

traverseInnerNode

protected void traverseInnerNode(Node node,
                                 Node parent,
                                 Scope refinedScope)

Traverses an inner node recursively with a refined scope. An inner node may be any node with a non null parent (i.e. all nodes except the root).

Parameters:

node - the node to traverse

parent - the node's parent, it may not be null

refinedScope - the refined scope of the scope currently at the top of the scope stack or in trivial cases that very scope or null

getCompiler

public Compiler getCompiler()

Gets the compiler.

getLineNumber

public int getLineNumber()

Gets the current line number, or zero if it cannot be determined. The line number is retrieved lazily as a running time optimization.

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.

getModule

public JSModule getModule()

Gets the current input module.

getCurrentNode

public Node getCurrentNode()

Returns the node currently being traversed.

traverse

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

Traverses a node recursively.

traverseRoots

public static void traverseRoots(AbstractCompiler compiler,
                                 java.util.List<Node> roots,
                                 NodeTraversal.Callback cb)

Traverses a list of node trees.

traverseRoots

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

getEnclosingFunction

public Node getEnclosingFunction()

Examines the functions stack for the last instance of a function node.

getScope

public Scope getScope()

Gets the current scope.

getControlFlowGraph

public com.google.javascript.jscomp.ControlFlowGraph<Node> getControlFlowGraph()

Gets the control flow graph for the current JS scope.

getScopeRoot

public Node getScopeRoot()

Returns the current scope's root.

hasScope

public boolean hasScope()

report

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

Reports a diagnostic (error or warning)

makeError

public JSError makeError(Node n,
                         CheckLevel level,
                         DiagnosticType type,
                         java.lang.String... arguments)

Creates a JSError during NodeTraversal.

Parameters:

n - Determines the line and char position within the source file name

type - The DiagnosticType

arguments - Arguments to be incorporated into the message

makeError

public JSError makeError(Node n,
                         DiagnosticType type,
                         java.lang.String... arguments)

Creates a JSError during NodeTraversal.

Parameters:

n - Determines the line and char position within the source file name

type - The DiagnosticType

arguments - Arguments to be incorporated into the message