Function identify

src/utils/array.js:573–594

(a)

 * @return {Array} An array of objects containing the original value and its identifier
 */
export function identify (a) {
  if (!Array.isArray(a)) {
    throw new TypeError('Array input expected')
  }

  if (a.length === 0) {
    return a
  }

  const b = []
  let count = 0
  b[0] = { value: a[0], identifier: 0 }
  for (let i = 1; i < a.length; i++) {
    if (a[i] === a[i - 1]) {
      count++
    } else {
      count = 0
    }
    b.push({ value: a[i], identifier: count })
  }
  return b
}

/**
 * Remove the numeric identifier from the elements