rx.coincidence.js

// Copyright (c) Microsoft, All rights reserved. See License.txt in the project root for license information.

;(function (factory) {
  var objectTypes = {
    'function': true,
    'object': true
  };

  function checkGlobal(value) {
    return (value && value.Object === Object) ? value : null;
  }

  var freeExports = (objectTypes[typeof exports] && exports && !exports.nodeType) ? exports : null;
  var freeModule = (objectTypes[typeof module] && module && !module.nodeType) ? module : null;
  var freeGlobal = checkGlobal(freeExports && freeModule && typeof global === 'object' && global);
  var freeSelf = checkGlobal(objectTypes[typeof self] && self);
  var freeWindow = checkGlobal(objectTypes[typeof window] && window);
  var moduleExports = (freeModule && freeModule.exports === freeExports) ? freeExports : null;
  var thisGlobal = checkGlobal(objectTypes[typeof this] && this);
  var root = freeGlobal || ((freeWindow !== (thisGlobal && thisGlobal.window)) && freeWindow) || freeSelf || thisGlobal || Function('return this')();

  // Because of build optimizers
  if (typeof define === 'function' && define.amd) {
    define(['./rx'], function (Rx, exports) {
      return factory(root, exports, Rx);
    });
  } else if (typeof module === 'object' && module && module.exports === freeExports) {
    module.exports = factory(root, module.exports, require('./rx'));
  } else {
    root.Rx = factory(root, {}, root.Rx);
  }
}.call(this, function (root, exp, Rx, undefined) {

  var Observable = Rx.Observable,
    ObservableBase = Rx.ObservableBase,
    AbstractObserver = Rx.internals.AbstractObserver,
    CompositeDisposable = Rx.CompositeDisposable,
    BinaryDisposable = Rx.BinaryDisposable,
    RefCountDisposable = Rx.RefCountDisposable,
    SingleAssignmentDisposable = Rx.SingleAssignmentDisposable,
    SerialDisposable = Rx.SerialDisposable,
    Subject = Rx.Subject,
    observableProto = Observable.prototype,
    observableEmpty = Observable.empty,
    observableNever = Observable.never,
    AnonymousObservable = Rx.AnonymousObservable,
    addRef = Rx.internals.addRef,
    inherits = Rx.internals.inherits,
    bindCallback = Rx.internals.bindCallback,
    noop = Rx.helpers.noop,
    isPromise = Rx.helpers.isPromise,
    isFunction = Rx.helpers.isFunction,
    observableFromPromise = Observable.fromPromise;

  var errorObj = {e: {}};
  
  function tryCatcherGen(tryCatchTarget) {
    return function tryCatcher() {
      try {
        return tryCatchTarget.apply(this, arguments);
      } catch (e) {
        errorObj.e = e;
        return errorObj;
      }
    };
  }

  var tryCatch = Rx.internals.tryCatch = function tryCatch(fn) {
    if (!isFunction(fn)) { throw new TypeError('fn must be a function'); }
    return tryCatcherGen(fn);
  };

  function thrower(e) {
    throw e;
  }

  var Map = root.Map || (function () {
    function Map() {
      this.size = 0;
      this._values = [];
      this._keys = [];
    }

    Map.prototype['delete'] = function (key) {
      var i = this._keys.indexOf(key);
      if (i === -1) { return false; }
      this._values.splice(i, 1);
      this._keys.splice(i, 1);
      this.size--;
      return true;
    };

    Map.prototype.get = function (key) {
      var i = this._keys.indexOf(key);
      return i === -1 ? undefined : this._values[i];
    };

    Map.prototype.set = function (key, value) {
      var i = this._keys.indexOf(key);
      if (i === -1) {
        this._keys.push(key);
        this._values.push(value);
        this.size++;
      } else {
        this._values[i] = value;
      }
      return this;
    };

    Map.prototype.forEach = function (cb, thisArg) {
      for (var i = 0; i < this.size; i++) {
        cb.call(thisArg, this._values[i], this._keys[i]);
      }
    };

    return Map;
  }());

  /**
   *  Correlates the elements of two sequences based on overlapping durations.
   *
   *  @param {Observable} right The right observable sequence to join elements for.
   *  @param {Function} leftDurationSelector A function to select the duration (expressed as an observable sequence) of each element of the left observable sequence, used to determine overlap.
   *  @param {Function} rightDurationSelector A function to select the duration (expressed as an observable sequence) of each element of the right observable sequence, used to determine overlap.
   *  @param {Function} resultSelector A function invoked to compute a result element for any two overlapping elements of the left and right observable sequences. The parameters passed to the function correspond with the elements from the left and right source sequences for which overlap occurs.
   *  @returns {Observable} An observable sequence that contains result elements computed from source elements that have an overlapping duration.
   */
  observableProto.join = function (right, leftDurationSelector, rightDurationSelector, resultSelector) {
    var left = this;
    return new AnonymousObservable(function (o) {
      var group = new CompositeDisposable();
      var leftDone = false, rightDone = false;
      var leftId = 0, rightId = 0;
      var leftMap = new Map(), rightMap = new Map();
      var handleError = function (e) { o.onError(e); };

      group.add(left.subscribe(
        function (value) {
          var id = leftId++, md = new SingleAssignmentDisposable();

          leftMap.set(id, value);
          group.add(md);

          var duration = tryCatch(leftDurationSelector)(value);
          if (duration === errorObj) { return o.onError(duration.e); }

          md.setDisposable(duration.take(1).subscribe(
            noop,
            handleError,
            function () {
              leftMap['delete'](id) && leftMap.size === 0 && leftDone && o.onCompleted();
              group.remove(md);
            }));

          rightMap.forEach(function (v) {
            var result = tryCatch(resultSelector)(value, v);
            if (result === errorObj) { return o.onError(result.e); }
            o.onNext(result);
          });
        },
        handleError,
        function () {
          leftDone = true;
          (rightDone || leftMap.size === 0) && o.onCompleted();
        })
      );

      group.add(right.subscribe(
        function (value) {
          var id = rightId++, md = new SingleAssignmentDisposable();

          rightMap.set(id, value);
          group.add(md);

          var duration = tryCatch(rightDurationSelector)(value);
          if (duration === errorObj) { return o.onError(duration.e); }

          md.setDisposable(duration.take(1).subscribe(
            noop,
            handleError,
            function () {
              rightMap['delete'](id) && rightMap.size === 0 && rightDone && o.onCompleted();
              group.remove(md);
            }));

          leftMap.forEach(function (v) {
            var result = tryCatch(resultSelector)(v, value);
            if (result === errorObj) { return o.onError(result.e); }
            o.onNext(result);
          });
        },
        handleError,
        function () {
          rightDone = true;
          (leftDone || rightMap.size === 0) && o.onCompleted();
        })
      );
      return group;
    }, left);
  };

  /**
   *  Correlates the elements of two sequences based on overlapping durations, and groups the results.
   *
   *  @param {Observable} right The right observable sequence to join elements for.
   *  @param {Function} leftDurationSelector A function to select the duration (expressed as an observable sequence) of each element of the left observable sequence, used to determine overlap.
   *  @param {Function} rightDurationSelector A function to select the duration (expressed as an observable sequence) of each element of the right observable sequence, used to determine overlap.
   *  @param {Function} resultSelector A function invoked to compute a result element for any element of the left sequence with overlapping elements from the right observable sequence. The first parameter passed to the function is an element of the left sequence. The second parameter passed to the function is an observable sequence with elements from the right sequence that overlap with the left sequence's element.
   *  @returns {Observable} An observable sequence that contains result elements computed from source elements that have an overlapping duration.
   */
  observableProto.groupJoin = function (right, leftDurationSelector, rightDurationSelector, resultSelector) {
    var left = this;
    return new AnonymousObservable(function (o) {
      var group = new CompositeDisposable();
      var r = new RefCountDisposable(group);
      var leftMap = new Map(), rightMap = new Map();
      var leftId = 0, rightId = 0;
      var handleError = function (e) { return function (v) { v.onError(e); }; };

      function handleError(e) { };

      group.add(left.subscribe(
        function (value) {
          var s = new Subject();
          var id = leftId++;
          leftMap.set(id, s);

          var result = tryCatch(resultSelector)(value, addRef(s, r));
          if (result === errorObj) {
            leftMap.forEach(handleError(result.e));
            return o.onError(result.e);
          }
          o.onNext(result);

          rightMap.forEach(function (v) { s.onNext(v); });

          var md = new SingleAssignmentDisposable();
          group.add(md);

          var duration = tryCatch(leftDurationSelector)(value);
          if (duration === errorObj) {
            leftMap.forEach(handleError(duration.e));
            return o.onError(duration.e);
          }

          md.setDisposable(duration.take(1).subscribe(
            noop,
            function (e) {
              leftMap.forEach(handleError(e));
              o.onError(e);
            },
            function () {
              leftMap['delete'](id) && s.onCompleted();
              group.remove(md);
            }));
        },
        function (e) {
          leftMap.forEach(handleError(e));
          o.onError(e);
        },
        function () { o.onCompleted(); })
      );

      group.add(right.subscribe(
        function (value) {
          var id = rightId++;
          rightMap.set(id, value);

          var md = new SingleAssignmentDisposable();
          group.add(md);

          var duration = tryCatch(rightDurationSelector)(value);
          if (duration === errorObj) {
            leftMap.forEach(handleError(duration.e));
            return o.onError(duration.e);
          }

          md.setDisposable(duration.take(1).subscribe(
            noop,
            function (e) {
              leftMap.forEach(handleError(e));
              o.onError(e);
            },
            function () {
              rightMap['delete'](id);
              group.remove(md);
            }));

          leftMap.forEach(function (v) { v.onNext(value); });
        },
        function (e) {
          leftMap.forEach(handleError(e));
          o.onError(e);
        })
      );

      return r;
    }, left);
  };

  function toArray(x) { return x.toArray(); }

  /**
   *  Projects each element of an observable sequence into zero or more buffers.
   *  @param {Mixed} bufferOpeningsOrClosingSelector Observable sequence whose elements denote the creation of new windows, or, a function invoked to define the boundaries of the produced windows (a new window is started when the previous one is closed, resulting in non-overlapping windows).
   *  @param {Function} [bufferClosingSelector] A function invoked to define the closing of each produced window. If a closing selector function is specified for the first parameter, this parameter is ignored.
   *  @returns {Observable} An observable sequence of windows.
   */
  observableProto.buffer = function () {
    return this.window.apply(this, arguments)
      .flatMap(toArray);
  };

  /**
   *  Projects each element of an observable sequence into zero or more windows.
   *
   *  @param {Mixed} windowOpeningsOrClosingSelector Observable sequence whose elements denote the creation of new windows, or, a function invoked to define the boundaries of the produced windows (a new window is started when the previous one is closed, resulting in non-overlapping windows).
   *  @param {Function} [windowClosingSelector] A function invoked to define the closing of each produced window. If a closing selector function is specified for the first parameter, this parameter is ignored.
   *  @returns {Observable} An observable sequence of windows.
   */
  observableProto.window = function (windowOpeningsOrClosingSelector, windowClosingSelector) {
    if (arguments.length === 1 && typeof arguments[0] !== 'function') {
      return observableWindowWithBoundaries.call(this, windowOpeningsOrClosingSelector);
    }
    return typeof windowOpeningsOrClosingSelector === 'function' ?
      observableWindowWithClosingSelector.call(this, windowOpeningsOrClosingSelector) :
      observableWindowWithOpenings.call(this, windowOpeningsOrClosingSelector, windowClosingSelector);
  };

  function observableWindowWithOpenings(windowOpenings, windowClosingSelector) {
    return windowOpenings.groupJoin(this, windowClosingSelector, observableEmpty, function (_, win) {
      return win;
    });
  }

  function observableWindowWithBoundaries(windowBoundaries) {
    var source = this;
    return new AnonymousObservable(function (observer) {
      var win = new Subject(),
        d = new CompositeDisposable(),
        r = new RefCountDisposable(d);

      observer.onNext(addRef(win, r));

      d.add(source.subscribe(function (x) {
        win.onNext(x);
      }, function (err) {
        win.onError(err);
        observer.onError(err);
      }, function () {
        win.onCompleted();
        observer.onCompleted();
      }));

      isPromise(windowBoundaries) && (windowBoundaries = observableFromPromise(windowBoundaries));

      d.add(windowBoundaries.subscribe(function (w) {
        win.onCompleted();
        win = new Subject();
        observer.onNext(addRef(win, r));
      }, function (err) {
        win.onError(err);
        observer.onError(err);
      }, function () {
        win.onCompleted();
        observer.onCompleted();
      }));

      return r;
    }, source);
  }

  function observableWindowWithClosingSelector(windowClosingSelector) {
    var source = this;
    return new AnonymousObservable(function (observer) {
      var m = new SerialDisposable(),
        d = new CompositeDisposable(m),
        r = new RefCountDisposable(d),
        win = new Subject();
      observer.onNext(addRef(win, r));
      d.add(source.subscribe(function (x) {
          win.onNext(x);
      }, function (err) {
          win.onError(err);
          observer.onError(err);
      }, function () {
          win.onCompleted();
          observer.onCompleted();
      }));

      function createWindowClose () {
        var windowClose;
        try {
          windowClose = windowClosingSelector();
        } catch (e) {
          observer.onError(e);
          return;
        }

        isPromise(windowClose) && (windowClose = observableFromPromise(windowClose));

        var m1 = new SingleAssignmentDisposable();
        m.setDisposable(m1);
        m1.setDisposable(windowClose.take(1).subscribe(noop, function (err) {
          win.onError(err);
          observer.onError(err);
        }, function () {
          win.onCompleted();
          win = new Subject();
          observer.onNext(addRef(win, r));
          createWindowClose();
        }));
      }

      createWindowClose();
      return r;
    }, source);
  }

  var PairwiseObservable = (function (__super__) {
    inherits(PairwiseObservable, __super__);
    function PairwiseObservable(source) {
      this.source = source;
      __super__.call(this);
    }

    PairwiseObservable.prototype.subscribeCore = function (o) {
      return this.source.subscribe(new PairwiseObserver(o));
    };

    return PairwiseObservable;
  }(ObservableBase));

  var PairwiseObserver = (function(__super__) {
    inherits(PairwiseObserver, __super__);
    function PairwiseObserver(o) {
      this._o = o;
      this._p = null;
      this._hp = false;
      __super__.call(this);
    }

    PairwiseObserver.prototype.next = function (x) {
      if (this._hp) {
        this._o.onNext([this._p, x]);
      } else {
        this._hp = true;
      }
      this._p = x;
    };
    PairwiseObserver.prototype.error = function (err) { this._o.onError(err); };
    PairwiseObserver.prototype.completed = function () { this._o.onCompleted(); };

    return PairwiseObserver;
  }(AbstractObserver));

  /**
   * Returns a new observable that triggers on the second and subsequent triggerings of the input observable.
   * The Nth triggering of the input observable passes the arguments from the N-1th and Nth triggering as a pair.
   * The argument passed to the N-1th triggering is held in hidden internal state until the Nth triggering occurs.
   * @returns {Observable} An observable that triggers on successive pairs of observations from the input observable as an array.
   */
  observableProto.pairwise = function () {
    return new PairwiseObservable(this);
  };

  /**
   * Returns two observables which partition the observations of the source by the given function.
   * The first will trigger observations for those values for which the predicate returns true.
   * The second will trigger observations for those values where the predicate returns false.
   * The predicate is executed once for each subscribed observer.
   * Both also propagate all error observations arising from the source and each completes
   * when the source completes.
   * @param {Function} predicate
   *    The function to determine which output Observable will trigger a particular observation.
   * @returns {Array}
   *    An array of observables. The first triggers when the predicate returns true,
   *    and the second triggers when the predicate returns false.
  */
  observableProto.partition = function(predicate, thisArg) {
    var fn = bindCallback(predicate, thisArg, 3);
    return [
      this.filter(predicate, thisArg),
      this.filter(function (x, i, o) { return !fn(x, i, o); })
    ];
  };

  /**
   *  Groups the elements of an observable sequence according to a specified key selector function and comparer and selects the resulting elements by using a specified function.
   *
   * @example
   *  var res = observable.groupBy(function (x) { return x.id; });
   *  2 - observable.groupBy(function (x) { return x.id; }), function (x) { return x.name; });
   *  3 - observable.groupBy(function (x) { return x.id; }), function (x) { return x.name; }, function (x) { return x.toString(); });
   * @param {Function} keySelector A function to extract the key for each element.
   * @param {Function} [elementSelector]  A function to map each source element to an element in an observable group.
   * @returns {Observable} A sequence of observable groups, each of which corresponds to a unique key value, containing all elements that share that same key value.
   */
  observableProto.groupBy = function (keySelector, elementSelector) {
    return this.groupByUntil(keySelector, elementSelector, observableNever);
  };

    /**
     *  Groups the elements of an observable sequence according to a specified key selector function.
     *  A duration selector function is used to control the lifetime of groups. When a group expires, it receives an OnCompleted notification. When a new element with the same
     *  key value as a reclaimed group occurs, the group will be reborn with a new lifetime request.
     *
     * @example
     *  var res = observable.groupByUntil(function (x) { return x.id; }, null,  function () { return Rx.Observable.never(); });
     *  2 - observable.groupBy(function (x) { return x.id; }), function (x) { return x.name; },  function () { return Rx.Observable.never(); });
     *  3 - observable.groupBy(function (x) { return x.id; }), function (x) { return x.name; },  function () { return Rx.Observable.never(); }, function (x) { return x.toString(); });
     * @param {Function} keySelector A function to extract the key for each element.
     * @param {Function} durationSelector A function to signal the expiration of a group.
     * @returns {Observable}
     *  A sequence of observable groups, each of which corresponds to a unique key value, containing all elements that share that same key value.
     *  If a group's lifetime expires, a new group with the same key value can be created once an element with such a key value is encoutered.
     *
     */
    observableProto.groupByUntil = function (keySelector, elementSelector, durationSelector) {
      var source = this;
      return new AnonymousObservable(function (o) {
        var map = new Map(),
          groupDisposable = new CompositeDisposable(),
          refCountDisposable = new RefCountDisposable(groupDisposable),
          handleError = function (e) { return function (item) { item.onError(e); }; };

        groupDisposable.add(
          source.subscribe(function (x) {
            var key = tryCatch(keySelector)(x);
            if (key === errorObj) {
              map.forEach(handleError(key.e));
              return o.onError(key.e);
            }

            var fireNewMapEntry = false, writer = map.get(key);
            if (writer === undefined) {
              writer = new Subject();
              map.set(key, writer);
              fireNewMapEntry = true;
            }

            if (fireNewMapEntry) {
              var group = new GroupedObservable(key, writer, refCountDisposable),
                durationGroup = new GroupedObservable(key, writer);
              var duration = tryCatch(durationSelector)(durationGroup);
              if (duration === errorObj) {
                map.forEach(handleError(duration.e));
                return o.onError(duration.e);
              }

              o.onNext(group);

              var md = new SingleAssignmentDisposable();
              groupDisposable.add(md);

              md.setDisposable(duration.take(1).subscribe(
                noop,
                function (e) {
                  map.forEach(handleError(e));
                  o.onError(e);
                },
                function () {
                  if (map['delete'](key)) { writer.onCompleted(); }
                  groupDisposable.remove(md);
                }));
            }

            var element = x;
            if (isFunction(elementSelector)) {
              element = tryCatch(elementSelector)(x);
              if (element === errorObj) {
                map.forEach(handleError(element.e));
                return o.onError(element.e);
              }
            }

            writer.onNext(element);
        }, function (e) {
          map.forEach(handleError(e));
          o.onError(e);
        }, function () {
          map.forEach(function (item) { item.onCompleted(); });
          o.onCompleted();
        }));

      return refCountDisposable;
    }, source);
  };

  var UnderlyingObservable = (function (__super__) {
    inherits(UnderlyingObservable, __super__);
    function UnderlyingObservable(m, u) {
      this._m = m;
      this._u = u;
      __super__.call(this);
    }

    UnderlyingObservable.prototype.subscribeCore = function (o) {
      return new BinaryDisposable(this._m.getDisposable(), this._u.subscribe(o));
    };

    return UnderlyingObservable;
  }(ObservableBase));

  var GroupedObservable = (function (__super__) {
    inherits(GroupedObservable, __super__);
    function GroupedObservable(key, underlyingObservable, mergedDisposable) {
      __super__.call(this);
      this.key = key;
      this.underlyingObservable = !mergedDisposable ?
        underlyingObservable :
        new UnderlyingObservable(mergedDisposable, underlyingObservable);
    }

    GroupedObservable.prototype._subscribe = function (o) {
      return this.underlyingObservable.subscribe(o);
    };

    return GroupedObservable;
  }(Observable));

  return Rx;
}));