Package com.google.javascript.jscomp

Interface NodeTraversal.Callback

All Known Subinterfaces:

NodeTraversal.ScopedCallback

All Known Implementing Classes:

BranchCoverageInstrumentationCallback, CheckArrayWithGoogObject, CheckConformance, CheckConstantCaseNames, CheckDuplicateCase, CheckEmptyStatements, CheckEnums, CheckEs6ModuleFileStructure, CheckEs6Modules, CheckExtraRequires, CheckInterfaces, CheckJSDocStyle, CheckMissingAndExtraRequires, CheckMissingRequires, CheckMissingSemicolon, CheckNoMutatedEs6Exports, CheckNullabilityModifiers, CheckNullableReturn, CheckPrimitiveAsObject, CheckPrototypeProperties, CheckProvidesSorted, CheckRequiresSorted, CheckTypeImportCodeReferences, CheckUnusedLabels, CheckUselessBlocks, ChromePass, ClosureCheckModule, ControlFlowAnalysis, ControlFlowGraph.AbstractCfgNodeTraversalCallback, CrossChunkReferenceCollector, DartSuperAccessorsPass, Es6CheckModule, Es6ConvertSuper, Es6ConvertSuperConstructorCalls, Es6ExtractClasses, Es6ForOfConverter, Es6NormalizeShorthandProperties, Es6RenameVariablesInParamLists, Es6RewriteArrowFunction, Es6RewriteBlockScopedDeclaration, Es6RewriteBlockScopedFunctionDeclaration, Es6RewriteClass, Es6RewriteClassExtendsExpressions, Es6RewriteDestructuring, Es6RewriteModules, Es6RewriteRestAndSpread, Es6RewriteScriptsToModules, Es6SplitVariableDeclarations, Es6TypedToEs6Converter, Es7RewriteExponentialOperator, EsModuleProcessor, FindModuleDependencies, ImplicitNullabilityCheck, InjectTranspilationRuntimeLibraries, J2clAssertRemovalPass, J2clChecksPass, J2clUtilGetDefineRewriterPass, JsMessageVisitor, LateEs6ToEs3Converter, MarkUntranspilableFeaturesAsRemoved, NodeTraversal.AbstractModuleCallback, NodeTraversal.AbstractPostOrderCallback, NodeTraversal.AbstractPreOrderCallback, NodeTraversal.AbstractScopedCallback, NodeTraversal.AbstractShallowCallback, NodeTraversal.AbstractShallowStatementCallback, NodeTraversal.ExternsSkippingCallback, ProcessCommonJSModules, ReferenceCollectingCallback, RewriteAsyncFunctions, RewriteAsyncIteration, RewriteJsonToModule, RewriteNullishCoalesceOperator, RewriteObjectSpread, TypeCheck

Enclosing class:

NodeTraversal

public static interface NodeTraversal.Callback

Callback for tree-based traversals

Method Summary

Modifier and Type	Method	Description
boolean	shouldTraverse(NodeTraversal t, Node n, Node parent)	Visits a node in preorder (before its children) and decides whether its children should be traversed.
void	visit(NodeTraversal t, Node n, Node parent)	Visits a node in postorder (after its children).

Method Detail

shouldTraverse

boolean shouldTraverse(NodeTraversal t,
                       Node n,
                       Node parent)

Visits a node in preorder (before its children) and decides whether its children should be traversed. If the children should be traversed, they will be visited by shouldTraverse(NodeTraversal, Node, Node) in preorder and by visit(NodeTraversal, Node, Node) in postorder.

Siblings are always visited left-to-right.

Implementations can have side-effects (e.g. modify the parse tree). Removing the current node is legal, but removing or reordering nodes above the current node may cause nodes to be visited twice or not at all.

Parameters:

t - The current traversal.

n - The current node.

parent - The parent of the current node.

Returns:

whether the children of this node should be visited

visit

void visit(NodeTraversal t,
           Node n,
           Node parent)

Visits a node in postorder (after its children). A node is visited in postorder iff shouldTraverse(NodeTraversal, Node, Node) returned true for its parent. In particular, the root node is never visited in postorder.

Siblings are always visited left-to-right.

Implementations can have side-effects (e.g. modify the parse tree). Removing the current node is legal, but removing or reordering nodes above the current node may cause nodes to be visited twice or not at all.

Parameters:

t - The current traversal.

n - The current node.

parent - The parent of the current node.