39 lines
1.4 KiB
JavaScript
39 lines
1.4 KiB
JavaScript
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//#region src/set/keyBy.ts
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/**
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* Maps each element of a Set based on a provided key-generating function.
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*
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* This function takes a Set and a function that generates a key from each value.
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* It returns a new Map where the keys are generated by the key function and the values are
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* the corresponding values from the original set. If multiple elements produce the same key,
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* the last value encountered will be used.
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*
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* @template T - The type of elements in the Set.
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* @template K - The type of keys to produce in the returned Map.
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* @param {Set<T>} set - The set of elements to be mapped.
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* @param {(value: T, value2: T, set: Set<T>) => K} getKeyFromValue - A function that generates a key from a value.
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* @returns {Map<K, T>} A Map where the generated keys are mapped to each element's value.
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*
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* @example
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* const set = new Set([
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* { type: 'fruit', name: 'apple' },
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* { type: 'fruit', name: 'banana' },
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* { type: 'vegetable', name: 'carrot' }
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* ]);
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* const result = keyBy(set, item => item.type);
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* // result will be:
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* // Map(2) {
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* // 'fruit' => { type: 'fruit', name: 'banana' },
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* // 'vegetable' => { type: 'vegetable', name: 'carrot' }
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* // }
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*/
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function keyBy(set, getKeyFromValue) {
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const result = /* @__PURE__ */ new Map();
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for (const value of set) {
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const newKey = getKeyFromValue(value, value, set);
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result.set(newKey, value);
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}
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return result;
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}
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//#endregion
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export { keyBy };
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