137 lines
2.9 KiB
JavaScript
137 lines
2.9 KiB
JavaScript
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/**
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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*
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* @format
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*/
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'use strict';
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.SimpleTraverserSkip = exports.SimpleTraverserBreak = exports.SimpleTraverser = void 0;
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var _getVisitorKeys = require("./getVisitorKeys");
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/**
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* Can be thrown within the traversal "enter" function to prevent the traverser
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* from traversing the node any further, essentially culling the remainder of the
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* AST branch
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*/
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const SimpleTraverserSkip = new Error();
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/**
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* Can be thrown at any point during the traversal to immediately stop traversal
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* entirely.
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*/
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exports.SimpleTraverserSkip = SimpleTraverserSkip;
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const SimpleTraverserBreak = new Error();
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/**
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* A very simple traverser class to traverse AST trees.
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*/
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exports.SimpleTraverserBreak = SimpleTraverserBreak;
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class SimpleTraverser {
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/**
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* Traverse the given AST tree.
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* @param node The root node to traverse.
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* @param options The option object.
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*/
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traverse(node, options) {
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try {
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this._traverse(node, null, options);
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} catch (ex) {
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if (ex === SimpleTraverserBreak) {
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return;
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}
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throw ex;
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}
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}
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/**
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* Traverse the given AST tree recursively.
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* @param node The current node.
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* @param parent The parent node.
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* @private
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*/
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_traverse(node, parent, options) {
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if (!(0, _getVisitorKeys.isNode)(node)) {
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return;
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}
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try {
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options.enter(node, parent);
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} catch (ex) {
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if (ex === SimpleTraverserSkip) {
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return;
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}
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this._setErrorContext(ex, node);
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throw ex;
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}
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const keys = (0, _getVisitorKeys.getVisitorKeys)(node, options.visitorKeys);
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for (const key of keys) {
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const child = node[key];
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if (Array.isArray(child)) {
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for (let j = 0; j < child.length; ++j) {
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this._traverse(child[j], node, options);
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}
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} else {
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this._traverse(child, node, options);
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}
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}
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try {
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options.leave(node, parent);
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} catch (ex) {
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if (ex === SimpleTraverserSkip) {
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return;
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}
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this._setErrorContext(ex, node);
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throw ex;
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}
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}
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/**
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* Set useful contextual information onto the error object.
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* @param ex The error object.
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* @param node The current node.
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* @private
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*/
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_setErrorContext(ex, node) {
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// $FlowFixMe[prop-missing]
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ex.currentNode = {
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type: node.type,
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range: node.range,
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loc: node.loc
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};
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}
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/**
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* Traverse the given AST tree.
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* @param node The root node to traverse.
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* @param options The option object.
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*/
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static traverse(node, options) {
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new SimpleTraverser().traverse(node, options);
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}
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}
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exports.SimpleTraverser = SimpleTraverser;
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SimpleTraverser.Break = SimpleTraverserBreak;
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SimpleTraverser.Skip = SimpleTraverserSkip;
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