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"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.getFallbackKeys = getFallbackKeys;
exports.getKeys = getKeys;
exports.getNodes = getNodes;
exports.traverseNodes = traverseNodes;
const visitor_keys_1 = require("./visitor-keys");
/**
* Check that the given key should be traversed or not.
* @this {Traversable}
* @param key The key to check.
* @returns `true` if the key should be traversed.
*/
function fallbackKeysFilter(key) {
let value = null;
return (key !== "comments" &&
key !== "leadingComments" &&
key !== "loc" &&
key !== "parent" &&
key !== "range" &&
key !== "tokens" &&
key !== "trailingComments" &&
(value = this[key]) !== null &&
typeof value === "object" &&
(typeof value.type === "string" || Array.isArray(value)));
}
/**
* Get the keys of the given node to traverse it.
* @param node The node to get.
* @returns The keys to traverse.
*/
function getFallbackKeys(node) {
return Object.keys(node).filter(fallbackKeysFilter, node);
}
/**
* Get the keys of the given node to traverse it.
* @param node The node to get.
* @returns The keys to traverse.
*/
function getKeys(node, visitorKeys) {
const keys = (visitorKeys || visitor_keys_1.KEYS)[node.type] || getFallbackKeys(node);
return keys.filter((key) => !getNodes(node, key).next().done);
}
/**
* Get the nodes of the given node.
* @param node The node to get.
*/
function* getNodes(node, key) {
const child = node[key];
if (Array.isArray(child)) {
for (const c of child) {
if (isNode(c)) {
yield c;
}
}
}
else if (isNode(child)) {
yield child;
}
}
/**
* Check whether a given value is a node.
* @param x The value to check.
* @returns `true` if the value is a node.
*/
function isNode(x) {
return x !== null && typeof x === "object" && typeof x.type === "string";
}
/**
* Traverse the given node.
* @param node The node to traverse.
* @param parent The parent node.
* @param visitor The node visitor.
*/
function traverse(node, parent, visitor) {
visitor.enterNode(node, parent);
const keys = getKeys(node, visitor.visitorKeys);
for (const key of keys) {
for (const child of getNodes(node, key)) {
traverse(child, node, visitor);
}
}
visitor.leaveNode(node, parent);
}
/**
* Traverse the given AST tree.
* @param node Root node to traverse.
* @param visitor Visitor.
*/
function traverseNodes(node, visitor) {
traverse(node, null, visitor);
}
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