NodeUtil (Closure Compiler v20170409 API)

java.lang.Object
- com.google.javascript.jscomp.NodeUtil

```
public final class NodeUtil
extends Object
```
NodeUtil contains generally useful AST utilities.

Author:

[email protected] (Nick Santos), [email protected] (John Lenz)

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface NodeUtil.Visitor
Interface for use with the visit method.

Nested Classes
Modifier and Type	Class and Description
`static interface`	`NodeUtil.Visitor` Interface for use with the visit method.

Field Summary

Fields
Modifier and Type Field and Description

static String EXTERN_OBJECT_PROPERTY_STRING

Fields
Modifier and Type	Field and Description
`static String`	`EXTERN_OBJECT_PROPERTY_STRING`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static boolean`	`containsType(Node node, Token type)`
`static Node`	`getAssignedValue(Node n)` For an assignment or variable declaration get the assigned value.
`static JSDocInfo`	`getBestJSDocInfo(Node n)` Find the best JSDoc for the given node.
`static Node`	`getClassMembers(Node n)`
`static int`	`getCount(Node n, com.google.common.base.Predicate<Node> pred, com.google.common.base.Predicate<Node> traverseChildrenPred)`
`static Node`	`getEnclosingBlock(Node n)` Finds the block containing the given node.
`static Node`	`getEnclosingBlockScopeRoot(Node n)`
`static Node`	`getEnclosingClass(Node n)` Finds the class containing the given node.
`static Node`	`getEnclosingFunction(Node n)` Finds the function containing the given node.
`static Node`	`getEnclosingNode(Node n, com.google.common.base.Predicate<Node> pred)`
`static Node`	`getEnclosingScopeRoot(Node n)`
`static Node`	`getEnclosingScript(Node n)` Finds the script containing the given node.
`static Node`	`getEnclosingStatement(Node n)`
`static Node`	`getEnclosingType(Node n, Token type)` Gets the closest ancestor to the given node of the provided type.
`static Node`	`getFunctionBody(Node fn)` Return a BLOCK node for the given FUNCTION node.
`static Node`	`getFunctionParameters(Node fnNode)`
`static InputId`	`getInputId(Node n)`
`static String`	`getName(Node n)`
`static Node`	`getNameNode(Node n)` Gets the node of a function or class's name.
`static String`	`getNearestFunctionName(Node n)` Gets the function's name.
`static Node`	`getNodeByLineCol(Node ancestor, int lineNo, int columNo)`
`static Double`	`getNumberValue(Node n)`
`static StaticSourceFile`	`getSourceFile(Node n)`
`static String`	`getSourceName(Node n)`
`static String`	`getStringValue(Node n)` Gets the value of a node as a String, or null if it cannot be converted.
`static boolean`	`has(Node node, com.google.common.base.Predicate<Node> pred, com.google.common.base.Predicate<Node> traverseChildrenPred)`
`static boolean`	`isAssignmentOp(Node n)`
`static boolean`	`isBooleanResult(Node n)`
`static boolean`	`isCallOrNew(Node node)`
`static boolean`	`isCallTo(Node n, String qualifiedName)`
`static boolean`	`isClassDeclaration(Node n)` see `isClassDeclaration(com.google.javascript.rhino.Node)`
`static boolean`	`isCompoundAssignementOp(Node n)`
`static boolean`	`isControlStructure(Node n)` Determines whether the given node is a FOR, DO, WHILE, WITH, or IF node.
`static boolean`	`isExprCall(Node n)` Is this node a call expression statement?
`static boolean`	`isFunctionDeclaration(Node n)` Is this node a function declaration? A function declaration is a function that has a name that is added to the current scope (i.e.
`static boolean`	`isGet(Node n)` Is this a GETPROP or GETELEM node?
`static boolean`	`isHoistedFunctionDeclaration(Node n)` Is this node a hoisted function declaration? A function declaration in the scope root is hoisted to the top of the scope.
`static boolean`	`isImportedName(Node n)`
`static boolean`	`isInFunction(Node n)`
`static boolean`	`isLhsByDestructuring(Node n)`
`static boolean`	`isLiteralValue(Node n, boolean includeFunctions)` Returns true if this is a literal value.
`static boolean`	`isLValue(Node n)` Determines whether this node is used as an L-value.
`static boolean`	`isNameDeclaration(Node n)` Is this node a name declaration?
`static boolean`	`isNullOrUndefined(Node n)`
`static boolean`	`isNumericResult(Node n)` Returns true if the result of node evaluation is always a number
`static boolean`	`isObjectResult(Node n)`
`static boolean`	`isPrototypePropertyDeclaration(Node n)`
`static boolean`	`isStatement(Node n)`
`static boolean`	`isStatementBlock(Node n)`
`static boolean`	`isStringResult(Node n)`
`static boolean`	`isTopLevel(Node n)`
`static boolean`	`isUndefined(Node n)`
`static boolean`	`isValidQualifiedName(CompilerOptions.LanguageMode mode, String name)` Determines whether the given name is a valid qualified name.
`static Map<Node,Node>`	`mapMainToClone(Node main, Node clone)` Given an AST and its copy, map the root node of each scope of main to the corresponding root node of clone
`static boolean`	`mayHaveSideEffects(Node n)` Returns true if the node which may have side effects when executed.
`static boolean`	`mayHaveSideEffects(Node n, AbstractCompiler compiler)`
`static Node`	`newPropertyAccess(AbstractCompiler compiler, Node context, String name)` Creates a property access on the `context` tree.
`static Node`	`newQName(AbstractCompiler compiler, String name)` Creates a node representing a qualified name.
`static Node`	`newQNameDeclaration(AbstractCompiler compiler, String name, Node value, JSDocInfo info)` Creates a node representing a qualified name.
`static String`	`opToStr(Token operator)` Converts an operator's token value (see `Token`) to a string representation.
`static void`	`removeChild(Node parent, Node node)` Safely remove children while maintaining a valid node structure.
`static void`	`removeName(Node n)` Set the given function/class node to an empty name
`static void`	`replaceDeclarationChild(Node declChild, Node newStatement)` Replace the child of a var/let/const declaration (usually a name) with a new statement.
`static boolean`	`tryMergeBlock(Node block)` Merge a block with its parent block.
`static void`	`verifyScopeChanges(Map<Node,Node> map, Node main, boolean verifyUnchangedNodes)` Checks that the scope roots marked as changed have indeed changed
`static void`	`visitPostOrder(Node node, NodeUtil.Visitor visitor, com.google.common.base.Predicate<Node> traverseChildrenPred)` A post-order traversal, calling Visitor.visit for each descendant matching the predicate.
`static void`	`visitPreOrder(Node node, NodeUtil.Visitor visitor)` A pre-order traversal, calling Visitor.visit for each decendent.
`static void`	`visitPreOrder(Node node, NodeUtil.Visitor visitor, com.google.common.base.Predicate<Node> traverseChildrenPred)` A pre-order traversal, calling Visitor.visit for each child matching the predicate.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EXTERN_OBJECT_PROPERTY_STRING
```
public static final String EXTERN_OBJECT_PROPERTY_STRING
```
    See Also:
    
    Constant Field Values
- Method Detail
  - getStringValue
```
public static String getStringValue(Node n)
```
    Gets the value of a node as a String, or null if it cannot be converted. When it returns a non-null String, this method effectively emulates the String() JavaScript cast function.
  - getNumberValue
```
public static Double getNumberValue(Node n)
```
  - getName
```
public static String getName(Node n)
```
    Parameters:
    
    n - A function or class node.
    
    Returns:
    
    The name of the given function or class, if it has one.
  - getNameNode
```
public static Node getNameNode(Node n)
```
    Gets the node of a function or class's name. This method recognizes five forms:
    - class name {...}
    - var name = class {...}
    - qualified.name = class {...}
    - var name2 = class name1 {...}
    - qualified.name2 = class name1 {...}
    In two last cases with named function expressions, the second name is returned (the variable or qualified name).
    Parameters:
    
    n - A function or class node
    
    Returns:
    
    the node best representing the class's name
  - removeName
```
public static void removeName(Node n)
```
    Set the given function/class node to an empty name
  - getNearestFunctionName
```
public static String getNearestFunctionName(Node n)
```
    Gets the function's name. This method recognizes the forms:
    - {'name': function() ...}
    - {name: function() ...}
    - function name() ...
    - var name = function() ...
    - var obj = {name() {} ...}
    - qualified.name = function() ...
    - var name2 = function name1() ...
    - qualified.name2 = function name1() ...
    Parameters:
    
    n - a node whose type is Token.FUNCTION
    
    Returns:
    
    the function's name, or null if it has no name
  - getClassMembers
```
public static Node getClassMembers(Node n)
```
  - isLiteralValue
```
public static boolean isLiteralValue(Node n,
                                     boolean includeFunctions)
```
    Returns true if this is a literal value. We define a literal value as any node that evaluates to the same thing regardless of when or where it is evaluated. So /xyz/ and [3, 5] are literals, but the name a is not.
    Function literals do not meet this definition, because they lexically capture variables. For example, if you have function() { return a; } If it is evaluated in a different scope, then it captures a different variable. Even if the function did not read any captured variables directly, it would still fail this definition, because it affects the lifecycle of variables in the enclosing scope.
    However, a function literal with respect to a particular scope is a literal.
    
    Parameters:
    
    includeFunctions - If true, all function expressions will be treated as literals.
  - mayHaveSideEffects
```
public static boolean mayHaveSideEffects(Node n)
```
    Returns true if the node which may have side effects when executed. This version default to the "safe" assumptions when the compiler object is not provided (RegExp have side-effects, etc).
  - mayHaveSideEffects
```
public static boolean mayHaveSideEffects(Node n,
                                         AbstractCompiler compiler)
```
  - isUndefined
```
public static boolean isUndefined(Node n)
```
  - isNullOrUndefined
```
public static boolean isNullOrUndefined(Node n)
```
  - isNumericResult
```
public static boolean isNumericResult(Node n)
```
    Returns true if the result of node evaluation is always a number
  - isBooleanResult
```
public static boolean isBooleanResult(Node n)
```
    Returns:
    
    Whether the result of node evaluation is always a boolean
  - isStringResult
```
public static boolean isStringResult(Node n)
```
    Returns:
    
    Whether the result of node evaluation is always a string
  - isObjectResult
```
public static boolean isObjectResult(Node n)
```
    Returns:
    
    Whether the result of node evaluation is always an object
  - isAssignmentOp
```
public static boolean isAssignmentOp(Node n)
```
  - isCompoundAssignementOp
```
public static boolean isCompoundAssignementOp(Node n)
```
  - getEnclosingType
```
public static Node getEnclosingType(Node n,
                                    Token type)
```
    Gets the closest ancestor to the given node of the provided type.
  - getEnclosingClass
```
public static Node getEnclosingClass(Node n)
```
    Finds the class containing the given node.
  - getEnclosingFunction
```
public static Node getEnclosingFunction(Node n)
```
    Finds the function containing the given node.
  - getEnclosingScript
```
public static Node getEnclosingScript(Node n)
```
    Finds the script containing the given node.
  - getEnclosingBlock
```
public static Node getEnclosingBlock(Node n)
```
    Finds the block containing the given node.
  - getEnclosingBlockScopeRoot
```
public static Node getEnclosingBlockScopeRoot(Node n)
```
  - getEnclosingScopeRoot
```
public static Node getEnclosingScopeRoot(Node n)
```
  - isInFunction
```
public static boolean isInFunction(Node n)
```
  - getEnclosingStatement
```
public static Node getEnclosingStatement(Node n)
```
  - getEnclosingNode
```
public static Node getEnclosingNode(Node n,
                                    com.google.common.base.Predicate<Node> pred)
```
  - isGet
```
public static boolean isGet(Node n)
```
    Is this a GETPROP or GETELEM node?
  - isNameDeclaration
```
public static boolean isNameDeclaration(Node n)
```
    Is this node a name declaration?
    
    Parameters:
    
    n - The node
    
    Returns:
    
    True if n is VAR, LET or CONST
  - getAssignedValue
```
public static Node getAssignedValue(Node n)
```
    For an assignment or variable declaration get the assigned value.
    
    Returns:
    
    The value node representing the new value.
  - isExprCall
```
public static boolean isExprCall(Node n)
```
    Is this node a call expression statement?
    
    Parameters:
    
    n - The node
    
    Returns:
    
    True if n is EXPR_RESULT and n's first child is CALL
  - isControlStructure
```
public static boolean isControlStructure(Node n)
```
    Determines whether the given node is a FOR, DO, WHILE, WITH, or IF node.
  - isStatementBlock
```
public static boolean isStatementBlock(Node n)
```
    Returns:
    
    Whether the node is of a type that contain other statements.
  - isStatement
```
public static boolean isStatement(Node n)
```
    Returns:
    
    Whether the node is used as a statement.
  - removeChild
```
public static void removeChild(Node parent,
                               Node node)
```
    Safely remove children while maintaining a valid node structure. In some cases, this is done by removing the parent from the AST as well.
  - replaceDeclarationChild
```
public static void replaceDeclarationChild(Node declChild,
                                           Node newStatement)
```
    Replace the child of a var/let/const declaration (usually a name) with a new statement. Preserves the order of side effects for all the other declaration children.
    
    Parameters:
    
    declChild - The name node to be replaced.
    
    newStatement - The statement to replace with.
  - tryMergeBlock
```
public static boolean tryMergeBlock(Node block)
```
    Merge a block with its parent block.
    
    Returns:
    
    Whether the block was removed.
  - isCallOrNew
```
public static boolean isCallOrNew(Node node)
```
    Parameters:
    
    node - A node
    
    Returns:
    
    Whether the call is a NEW or CALL node.
  - getFunctionBody
```
public static Node getFunctionBody(Node fn)
```
    Return a BLOCK node for the given FUNCTION node.
  - isFunctionDeclaration
```
public static boolean isFunctionDeclaration(Node n)
```
    Is this node a function declaration? A function declaration is a function that has a name that is added to the current scope (i.e. a function that is not part of a expression; see isFunctionExpression(com.google.javascript.rhino.Node)).
  - isClassDeclaration
```
public static boolean isClassDeclaration(Node n)
```
    see isClassDeclaration(com.google.javascript.rhino.Node)
  - isHoistedFunctionDeclaration
```
public static boolean isHoistedFunctionDeclaration(Node n)
```
    Is this node a hoisted function declaration? A function declaration in the scope root is hoisted to the top of the scope. See isFunctionDeclaration(com.google.javascript.rhino.Node)).
  - isLValue
```
public static boolean isLValue(Node n)
```
    Determines whether this node is used as an L-value. Notice that sometimes names are used as both L-values and R-values.
    We treat "var x;" and "let x;" as an L-value because it's syntactically similar to "var x = undefined", even though it's technically not an L-value. But it kind of makes sense if you treat it as "assignment to 'undefined' at the top of the scope".
    
    Parameters:
    
    n - The node
    
    Returns:
    
    True if n is an L-value.
  - isImportedName
```
public static boolean isImportedName(Node n)
```
  - isLhsByDestructuring
```
public static boolean isLhsByDestructuring(Node n)
```
  - opToStr
```
public static String opToStr(Token operator)
```
    Converts an operator's token value (see Token) to a string representation.
    
    Parameters:
    
    operator - the operator's token value to convert
    
    Returns:
    
    the string representation or null if the token value is not an operator
  - containsType
```
public static boolean containsType(Node node,
                                   Token type)
```
    Returns:
    
    true if n or any of its descendants are of the specified type.
  - newQName
```
public static Node newQName(AbstractCompiler compiler,
                            String name)
```
    Creates a node representing a qualified name.
    
    Parameters:
    
    name - A qualified name (e.g. "foo" or "foo.bar.baz")
    
    Returns:
    
    A NAME or GETPROP node
  - newPropertyAccess
```
public static Node newPropertyAccess(AbstractCompiler compiler,
                                     Node context,
                                     String name)
```
    Creates a property access on the context tree.
  - newQNameDeclaration
```
public static Node newQNameDeclaration(AbstractCompiler compiler,
                                       String name,
                                       Node value,
                                       JSDocInfo info)
```
    Creates a node representing a qualified name.
    
    Parameters:
    
    name - A qualified name (e.g. "foo" or "foo.bar.baz")
    
    Returns:
    
    A VAR node, or an EXPR_RESULT node containing an ASSIGN or NAME node.
  - isValidQualifiedName
```
public static boolean isValidQualifiedName(CompilerOptions.LanguageMode mode,
                                           String name)
```
    Determines whether the given name is a valid qualified name.
  - isPrototypePropertyDeclaration
```
public static boolean isPrototypePropertyDeclaration(Node n)
```
    Returns:
    
    true if the node an assignment to a prototype property of some constructor.
  - has
```
public static boolean has(Node node,
                          com.google.common.base.Predicate<Node> pred,
                          com.google.common.base.Predicate<Node> traverseChildrenPred)
```
    Returns:
    
    Whether the predicate is true for the node or any of its descendants.
  - getCount
```
public static int getCount(Node n,
                           com.google.common.base.Predicate<Node> pred,
                           com.google.common.base.Predicate<Node> traverseChildrenPred)
```
    Returns:
    
    The number of times the the predicate is true for the node or any of its descendants.
  - visitPreOrder
```
public static void visitPreOrder(Node node,
                                 NodeUtil.Visitor visitor)
```
    A pre-order traversal, calling Visitor.visit for each decendent.
  - visitPreOrder
```
public static void visitPreOrder(Node node,
                                 NodeUtil.Visitor visitor,
                                 com.google.common.base.Predicate<Node> traverseChildrenPred)
```
    A pre-order traversal, calling Visitor.visit for each child matching the predicate.
  - visitPostOrder
```
public static void visitPostOrder(Node node,
                                  NodeUtil.Visitor visitor,
                                  com.google.common.base.Predicate<Node> traverseChildrenPred)
```
    A post-order traversal, calling Visitor.visit for each descendant matching the predicate.
  - getFunctionParameters
```
public static Node getFunctionParameters(Node fnNode)
```
    Parameters:
    
    fnNode - The function.
    
    Returns:
    
    The Node containing the Function parameters.
  - getSourceName
```
public static String getSourceName(Node n)
```
    Parameters:
    
    n - The node.
    
    Returns:
    
    The source name property on the node or its ancestors.
  - getSourceFile
```
public static StaticSourceFile getSourceFile(Node n)
```
    Parameters:
    
    n - The node.
    
    Returns:
    
    The source name property on the node or its ancestors.
  - getInputId
```
public static InputId getInputId(Node n)
```
    Parameters:
    
    n - The node.
    
    Returns:
    
    The InputId property on the node or its ancestors.
  - getNodeByLineCol
```
public static Node getNodeByLineCol(Node ancestor,
                                    int lineNo,
                                    int columNo)
```
  - getBestJSDocInfo
```
@Nullable
public static JSDocInfo getBestJSDocInfo(Node n)
```
    Find the best JSDoc for the given node.
  - mapMainToClone
```
public static Map<Node,Node> mapMainToClone(Node main,
                                            Node clone)
```
    Given an AST and its copy, map the root node of each scope of main to the corresponding root node of clone
  - verifyScopeChanges
```
public static void verifyScopeChanges(Map<Node,Node> map,
                                      Node main,
                                      boolean verifyUnchangedNodes)
```
    Checks that the scope roots marked as changed have indeed changed
  - isTopLevel
```
public static boolean isTopLevel(Node n)
```
  - isCallTo
```
public static boolean isCallTo(Node n,
                               String qualifiedName)
```

Class NodeUtil

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EXTERN_OBJECT_PROPERTY_STRING

Method Detail

getStringValue

getNumberValue

getName

getNameNode

removeName

getNearestFunctionName

getClassMembers

isLiteralValue

mayHaveSideEffects

mayHaveSideEffects

isUndefined

isNullOrUndefined

isNumericResult

isBooleanResult

isStringResult

isObjectResult

isAssignmentOp

isCompoundAssignementOp

getEnclosingType

getEnclosingClass

getEnclosingFunction

getEnclosingScript

getEnclosingBlock

getEnclosingBlockScopeRoot

getEnclosingScopeRoot

isInFunction

getEnclosingStatement

getEnclosingNode

isGet

isNameDeclaration

getAssignedValue

isExprCall

isControlStructure

isStatementBlock

isStatement

removeChild

replaceDeclarationChild

tryMergeBlock

isCallOrNew

getFunctionBody

isFunctionDeclaration

isClassDeclaration

isHoistedFunctionDeclaration

isLValue

isImportedName

isLhsByDestructuring

opToStr

containsType

newQName

newPropertyAccess

newQNameDeclaration

isValidQualifiedName

isPrototypePropertyDeclaration

has

getCount

visitPreOrder

visitPreOrder

visitPostOrder

getFunctionParameters

getSourceName

getSourceFile

getInputId

getNodeByLineCol

getBestJSDocInfo

mapMainToClone

verifyScopeChanges

isTopLevel

isCallTo