Function makeMap

docs/themes/htx/source/js/vue.js:108–121

* Make a map and return a function for checking if a key * is in that map.

(str, expectsLowerCase)

   * is in that map.
   */
  function makeMap(str, expectsLowerCase) {
    var map = Object.create(null);
    var list = str.split(",");
    for (var i = 0; i < list.length; i++) {
      map[list[i]] = true;
    }
    return expectsLowerCase
      ? function(val) {
          return map[val.toLowerCase()];
        }
      : function(val) {
          return map[val];
        };
  }

  /**
   * Check if a tag is a built-in tag.