LendAndRegret/node_modules/es-toolkit/dist/set/reduce.d.ts
2026-05-02 17:27:43 +08:00

29 lines
1.4 KiB
TypeScript

/**
* Reduces a Set to a single value by iterating through its elements and applying a callback function.
*
* This function iterates through all elements of the Set and applies the callback function to each element,
* accumulating the result. If an initial value is provided, it is used as the starting accumulator value.
* If no initial value is provided and the Set is empty, a TypeError is thrown.
*
* @template T - The type of elements in the Set.
* @template A - The type of the accumulator.
* @param {Set<T>} set - The Set to reduce.
* @param {(accumulator: A, value: T, value2: T, set: Set<T>) => A} callback - A function that processes each element and updates the accumulator.
* @param {A} [initialValue] - The initial value for the accumulator. If not provided, the first element in the Set is used.
* @returns {A} The final accumulated value.
* @throws {TypeError} If the Set is empty and no initial value is provided.
*
* @example
* const set = new Set([1, 2, 3]);
* const result = reduce(set, (acc, value) => acc + value, 0);
* // result will be: 6
*
* @example
* const set = new Set([10, 20]);
* const result = reduce(set, (acc, value) => acc + value);
* // result will be: 30 (starts with first value 10)
*/
declare function reduce<T, A = T>(set: Set<T>, callback: (accumulator: A, value: T, value2: T, set: Set<T>) => A, initialValue?: A): A;
export { reduce };