Function compact2array

lib/util.js:54–75

* 组合两个拼音数组，形成一个新的二维数组 * @param {string[]|string[][]} arr1 eg: ["hai", "huan"] * @param {Array } arr2 eg: ["qian"] * @returns {string[][]} 组合后的二维数组，eg: [ ["hai", "qian"], ["huan", "qian"] ]

(a1, a2)

 * @returns {string[][]} 组合后的二维数组，eg: [ ["hai", "qian"], ["huan", "qian"] ]
 */
function compact2array(a1, a2) {
  if (!Array.isArray(a1) || !Array.isArray(a2)) {
    throw new Error("compact2array expect two array as parameters");
  }
  if (!a1.length) {
    a1 = [""];
  }
  if (!a2.length) {
    a2 = [""];
  }
  const result = [];
  for (let i = 0, l = a1.length; i < l; i++) {
    for (let j = 0, m = a2.length; j < m; j++) {
      if (Array.isArray(a1[i])) {
        result.push([...a1[i], a2[j]]);
      } else {
        result.push([a1[i], a2[j]]);
      }
    }
  }
  return result;
}

function compact(arr) {
  if (arr.length === 0) {