Function arraySpliceIn

packages/effect/src/internal/hashMap/array.ts:34–49

(mutate: boolean, at: number, v: A, arr: Array<A>)

/** @internal */
export function arraySpliceIn<A>(mutate: boolean, at: number, v: A, arr: Array<A>) {
  const len = arr.length
  if (mutate) {
    let i = len
    while (i >= at) arr[i--] = arr[i]!
    arr[at] = v
    return arr
  }
  let i = 0,
    g = 0
  const out = new Array<A>(len + 1)
  while (i < at) out[g++] = arr[i++]!
  out[at] = v
  while (i < len) out[++g] = arr[i++]!
  return out
}