// @ts-check
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import { WalkerBase } from './walker.js';
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/** @typedef { import('estree').BaseNode} BaseNode */
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/** @typedef { import('./walker.js').WalkerContext} WalkerContext */
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/** @typedef {(
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* this: WalkerContext,
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* node: BaseNode,
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* parent: BaseNode,
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* key: string,
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* index: number
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* ) => void} SyncHandler */
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export class SyncWalker extends WalkerBase {
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/**
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*
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* @param {SyncHandler} enter
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* @param {SyncHandler} leave
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*/
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constructor(enter, leave) {
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super();
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/** @type {SyncHandler} */
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this.enter = enter;
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/** @type {SyncHandler} */
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this.leave = leave;
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}
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/**
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*
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* @param {BaseNode} node
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* @param {BaseNode} parent
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* @param {string} [prop]
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* @param {number} [index]
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* @returns {BaseNode}
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*/
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visit(node, parent, prop, index) {
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if (node) {
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if (this.enter) {
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const _should_skip = this.should_skip;
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const _should_remove = this.should_remove;
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const _replacement = this.replacement;
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this.should_skip = false;
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this.should_remove = false;
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this.replacement = null;
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this.enter.call(this.context, node, parent, prop, index);
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if (this.replacement) {
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node = this.replacement;
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this.replace(parent, prop, index, node);
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}
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if (this.should_remove) {
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this.remove(parent, prop, index);
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}
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const skipped = this.should_skip;
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const removed = this.should_remove;
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this.should_skip = _should_skip;
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this.should_remove = _should_remove;
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this.replacement = _replacement;
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if (skipped) return node;
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if (removed) return null;
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}
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for (const key in node) {
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const value = node[key];
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if (typeof value !== "object") {
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continue;
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} else if (Array.isArray(value)) {
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for (let i = 0; i < value.length; i += 1) {
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if (value[i] !== null && typeof value[i].type === 'string') {
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if (!this.visit(value[i], node, key, i)) {
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// removed
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i--;
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}
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}
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}
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} else if (value !== null && typeof value.type === "string") {
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this.visit(value, node, key, null);
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}
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}
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if (this.leave) {
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const _replacement = this.replacement;
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const _should_remove = this.should_remove;
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this.replacement = null;
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this.should_remove = false;
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this.leave.call(this.context, node, parent, prop, index);
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if (this.replacement) {
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node = this.replacement;
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this.replace(parent, prop, index, node);
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}
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if (this.should_remove) {
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this.remove(parent, prop, index);
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}
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const removed = this.should_remove;
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this.replacement = _replacement;
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this.should_remove = _should_remove;
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if (removed) return null;
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}
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}
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return node;
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}
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}
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