'use strict';
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const Assert = require('./assert');
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const internals = {};
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module.exports = function (obj, chain, options) {
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if (chain === false ||
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chain === null ||
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chain === undefined) {
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return obj;
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}
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options = options || {};
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if (typeof options === 'string') {
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options = { separator: options };
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}
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const isChainArray = Array.isArray(chain);
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Assert(!isChainArray || !options.separator, 'Separator option no valid for array-based chain');
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const path = isChainArray ? chain : chain.split(options.separator || '.');
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let ref = obj;
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for (let i = 0; i < path.length; ++i) {
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let key = path[i];
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const type = options.iterables && internals.iterables(ref);
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if (Array.isArray(ref) ||
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type === 'set') {
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const number = Number(key);
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if (Number.isInteger(number)) {
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key = number < 0 ? ref.length + number : number;
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}
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}
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if (!ref ||
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typeof ref === 'function' && options.functions === false || // Defaults to true
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!type && ref[key] === undefined) {
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Assert(!options.strict || i + 1 === path.length, 'Missing segment', key, 'in reach path ', chain);
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Assert(typeof ref === 'object' || options.functions === true || typeof ref !== 'function', 'Invalid segment', key, 'in reach path ', chain);
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ref = options.default;
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break;
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}
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if (!type) {
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ref = ref[key];
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}
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else if (type === 'set') {
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ref = [...ref][key];
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}
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else { // type === 'map'
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ref = ref.get(key);
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}
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}
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return ref;
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};
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internals.iterables = function (ref) {
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if (ref instanceof Set) {
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return 'set';
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}
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if (ref instanceof Map) {
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return 'map';
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}
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};
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