42 lines
1.9 KiB
JavaScript
42 lines
1.9 KiB
JavaScript
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//#region src/array/windowed.ts
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/**
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* Creates an array of sub-arrays (windows) from the input array, each of the specified size.
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* The windows can overlap depending on the step size provided.
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*
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* By default, only full windows are included in the result, and any leftover elements that can't form a full window are ignored.
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*
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* If the `partialWindows` option is set to true in the options object, the function will also include partial windows at the end of the result.
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* Partial windows are smaller sub-arrays created when there aren't enough elements left in the input array to form a full window.
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*
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* @template T
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* @param {readonly T[]} arr - The input array to create windows from.
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* @param {number} size - The size of each window. Must be a positive integer.
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* @param {number} [step=1] - The step size between the start of each window. Must be a positive integer.
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* @param {WindowedOptions} [options={}] - Options object to configure the behavior of the function.
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* @param {boolean} [options.partialWindows=false] - Whether to include partial windows at the end of the array.
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* @returns {T[][]} An array of windows (sub-arrays) created from the input array.
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* @throws {Error} If the size or step is not a positive integer.
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*
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* @example
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* windowed([1, 2, 3, 4], 2);
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* // => [[1, 2], [2, 3], [3, 4]]
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*
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* @example
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* windowed([1, 2, 3, 4, 5, 6], 3, 2);
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* // => [[1, 2, 3], [3, 4, 5]]
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*
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* @example
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* windowed([1, 2, 3, 4, 5, 6], 3, 2, { partialWindows: true });
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* // => [[1, 2, 3], [3, 4, 5], [5, 6]]
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*/
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function windowed(arr, size, step = 1, { partialWindows = false } = {}) {
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if (size <= 0 || !Number.isInteger(size)) throw new Error("Size must be a positive integer.");
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if (step <= 0 || !Number.isInteger(step)) throw new Error("Step must be a positive integer.");
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const result = [];
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const end = partialWindows ? arr.length : arr.length - size + 1;
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for (let i = 0; i < end; i += step) result.push(arr.slice(i, i + size));
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return result;
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}
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//#endregion
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exports.windowed = windowed;
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