callbag-distinct-until-changed/dist/callbag-distinct-until-changed.es.js

👜 Callbag operator that drops consecutive duplicate values

var is = function is(previous, current) {
  return previous === current;
};

function distinctUntilChanged(compare) {
  if (compare === void 0) {
    compare = is;
  }

  return function (source) {
    return function (start, sink) {
      if (start !== 0) return;
      var inited = false;
      var prev;
      var talkback;
      source(0, function (type, data) {
        if (type === 0) {
          talkback = data;
        }

        if (type !== 1) {
          sink(type, data);
          return;
        }

        if (inited && compare(prev, data)) {
          talkback(1);
          return;
        }

        inited = true;
        prev = data;
        sink(1, data);
      });
    };
  };
}

export default distinctUntilChanged;