reblendjs/src/internal/DiffUtil.ts

ReblendJs uses Reactjs pradigm to build UI components, with isolated state for each components.

/* eslint-disable @typescript-eslint/no-explicit-any */

/**
 * Deeply flattens an array or set of elements.
 *
 * @template T
 * @param {T[] | Set<T>} data - The data to flatten.
 * @returns {T[]} A flattened array of elements.
 */
export function deepFlat<T>(data: T[] | Set<T>): T[] {
  if (!data) {
    return []
  }
  if (!(data instanceof Set) && !Array.isArray(data)) {
    data = [data]
  }
  const ts: T[] = []
  for (const t of data) {
    if (t instanceof Set || Array.isArray(t)) {
      ts.push(...deepFlat(t))
    } else {
      ts.push(t)
    }
  }
  return ts
}

/**
 * Flattens a nested array or set of virtual nodes (VNode) and adds the result to the `containerArr`.
 *
 * @template T
 * @param {(T | T[])[] | Set<T | T[]>} arr - The array or set of VNode children to flatten.
 * @param {T[]} [containerArr=[]] - The container array to store flattened nodes.
 * @returns {T[]} The flattened array of VNode children.
 */
export function flattenVNodeChildren<T>(arr: (T | T[])[] | Set<T | T[]>, containerArr: T[] = []): T[] {
  if (!arr) {
    return []
  }

  if (!Array.isArray(arr)) {
    arr = [arr as any]
  }

  if ((arr.length || (arr as any).size) < 1) {
    return []
  }

  for (const item of arr) {
    if (item instanceof Set || Array.isArray(item)) {
      flattenVNodeChildren(item as T[], containerArr)
    } else {
      containerArr.push(item as T)
    }
  }

  return containerArr
}