7820380e
 “wangming”
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// @ts-check
import { WalkerBase } from './walker.js';
/** @typedef { import('estree').BaseNode} BaseNode */
/** @typedef { import('./walker.js').WalkerContext} WalkerContext */
/** @typedef {(
* this: WalkerContext,
* node: BaseNode,
* parent: BaseNode,
* key: string,
* index: number
* ) => void} SyncHandler */
export class SyncWalker extends WalkerBase {
/**
*
* @param {SyncHandler} enter
* @param {SyncHandler} leave
*/
constructor(enter, leave) {
super();
/** @type {SyncHandler} */
this.enter = enter;
/** @type {SyncHandler} */
this.leave = leave;
}
/**
*
* @param {BaseNode} node
* @param {BaseNode} parent
* @param {string} [prop]
* @param {number} [index]
* @returns {BaseNode}
*/
visit(node, parent, prop, index) {
if (node) {
if (this.enter) {
const _should_skip = this.should_skip;
const _should_remove = this.should_remove;
const _replacement = this.replacement;
this.should_skip = false;
this.should_remove = false;
this.replacement = null;
this.enter.call(this.context, node, parent, prop, index);
if (this.replacement) {
node = this.replacement;
this.replace(parent, prop, index, node);
}
if (this.should_remove) {
this.remove(parent, prop, index);
}
const skipped = this.should_skip;
const removed = this.should_remove;
this.should_skip = _should_skip;
this.should_remove = _should_remove;
this.replacement = _replacement;
if (skipped) return node;
if (removed) return null;
}
for (const key in node) {
const value = node[key];
if (typeof value !== "object") {
continue;
} else if (Array.isArray(value)) {
for (let i = 0; i < value.length; i += 1) {
if (value[i] !== null && typeof value[i].type === 'string') {
if (!this.visit(value[i], node, key, i)) {
// removed
i--;
}
}
}
} else if (value !== null && typeof value.type === "string") {
this.visit(value, node, key, null);
}
}
if (this.leave) {
const _replacement = this.replacement;
const _should_remove = this.should_remove;
this.replacement = null;
this.should_remove = false;
this.leave.call(this.context, node, parent, prop, index);
if (this.replacement) {
node = this.replacement;
this.replace(parent, prop, index, node);
}
if (this.should_remove) {
this.remove(parent, prop, index);
}
const removed = this.should_remove;
this.replacement = _replacement;
this.should_remove = _should_remove;
if (removed) return null;
}
}
return node;
}
}
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