sangja/src/utils.js

JavaScript data structures library

/**
 * Check if given object is iterable
 * @function
 * @memberof sangja
 * @param {*} obj - An object to check if iterable
 * @return {boolean} True if obj is iterable else false
 */
function isIterable(obj) {
  // checks for null and undefined
  if (obj == null) {
    return false;
  }
  return typeof obj[Symbol.iterator] === 'function';
}

/**
 * Default key function.<br>
 * Data structures that require compare will use this function as a default key function.<br>
 * Returns the input argument as it is.
 * @function
 * @memberof sangja
 */
const defaultKey = x => x;

/**
 * Default compare function.<br>
 * Data structures that require compare will use this function as a default compare function.<br>
 * Compare 2 given operands and return the result. This function can compare number, string.
 * @function
 * @memberof sangja
 */
const defaultCompare = (x, y) => {
  if (x < y) {
    return -1;
  }
  if (x > y) {
    return 1;
  }
  return 0;
};

function mergeOptions(given = {}, original = {}) {
  if (!given) {
    return original;
  }

  const merged = {};
  Object.keys(original).forEach((key) => {
    merged[key] = given[key] || original[key];
  });
  return merged;
}

module.exports = {
  isIterable,
  defaultKey,
  defaultCompare,
  mergeOptions,
};