46 lines
1.8 KiB
JavaScript
46 lines
1.8 KiB
JavaScript
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import { identity } from "../../function/identity.mjs";
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import { isNil } from "../../predicate/isNil.mjs";
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import { iteratee } from "../util/iteratee.mjs";
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//#region src/compat/object/invertBy.ts
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/**
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* Creates a new object that reverses the keys and values of the given object, similar to the invert.
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*
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* The `iteratee` function specifies how the values are reversed into keys. If no `iteratee` function is provided, the values are used as keys as-is.
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*
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* The values of the new object are arrays of keys that correspond to the value returned by the `iteratee` function.
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*
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* @param {Record<K, V>} object - The object to iterate over.
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* @param {(value: V) => string} [iteratee] - Optional. A function that generates a key based on each value in the object.
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* If not provided, the function defaults to using the value as a string.
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*
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* @returns {Record<string, K[]>} An object where the keys are generated by the iteratee, and the values
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* are arrays of property names (keys) from the input object that correspond to those keys.
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*
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* @example
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* const obj = { a: 1, b: 2, c: 1 };
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* const result = invertBy(obj);
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* // result => { '1': ['a', 'c'], '2': ['b'] }
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*
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* @example
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* const obj = { a: 1, b: 2, c: 1 };
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* const result = invertBy(obj, value => `group${value}`);
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* // result => { 'group1': ['a', 'c'], 'group2': ['b'] }
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*/
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function invertBy(object, iteratee$1) {
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const result = {};
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if (isNil(object)) return result;
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if (iteratee$1 == null) iteratee$1 = identity;
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const keys = Object.keys(object);
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const getString = iteratee(iteratee$1);
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for (let i = 0; i < keys.length; i++) {
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const key = keys[i];
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const value = object[key];
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const valueStr = getString(value);
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if (Array.isArray(result[valueStr])) result[valueStr].push(key);
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else result[valueStr] = [key];
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}
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return result;
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}
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//#endregion
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export { invertBy };
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