fix(Observable): introduce Subscribable interface to use instead of Observable in input arguments

src/Observable.ts

@@ -1,4 +1,4 @@
-import {PartialObserver} from './Observer';
+import {PartialObserver, Observer} from './Observer';
 import {Operator} from './Operator';
 import {Subscriber} from './Subscriber';
 import {Subscription} from './Subscription';
@@ -9,17 +9,21 @@ import {toSubscriber} from './util/toSubscriber';
 import {IfObservable} from './observable/IfObservable';
 import {ErrorObservable} from './observable/ErrorObservable';
 
-export type ObservableOrPromise<T> = Observable<T> | Promise<T>;
+export interface Subscribable<T> {
+  subscribe(observer: Observer<T>): Subscription;
+}
+
+export type SubscribableOrPromise<T> = Subscribable<T> | Promise<T>;
 export type ArrayOrIterator<T> = Iterator<T> | ArrayLike<T>;
-export type ObservableInput<T> = ObservableOrPromise<T> | ArrayOrIterator<T>;
+export type ObservableInput<T> = SubscribableOrPromise<T> | ArrayOrIterator<T>;
 
 /**
  * A representation of any set of values over any amount of time. This the most basic building block
  * of RxJS.
  *
  * @class Observable<T>
  */
-export class Observable<T> {
+export class Observable<T> implements Subscribable<T> {
 
   public _isScalar: boolean = false;
 

src/operator/debounce.ts

@@ -1,5 +1,5 @@
 import {Operator} from '../Operator';
-import {Observable, ObservableOrPromise} from '../Observable';
+import {Observable, SubscribableOrPromise} from '../Observable';
 import {Subscriber} from '../Subscriber';
 import {Subscription} from '../Subscription';
 
@@ -19,16 +19,16 @@ import {subscribeToResult} from '../util/subscribeToResult';
  * @method debounce
  * @owner Observable
  */
-export function debounce<T>(durationSelector: (value: T) => ObservableOrPromise<number>): Observable<T> {
+export function debounce<T>(durationSelector: (value: T) => SubscribableOrPromise<number>): Observable<T> {
   return this.lift(new DebounceOperator(durationSelector));
 }
 
 export interface DebounceSignature<T> {
-  (durationSelector: (value: T) => ObservableOrPromise<number>): Observable<T>;
+  (durationSelector: (value: T) => SubscribableOrPromise<number>): Observable<T>;
 }
 
 class DebounceOperator<T> implements Operator<T, T> {
-  constructor(private durationSelector: (value: T) => ObservableOrPromise<number>) {
+  constructor(private durationSelector: (value: T) => SubscribableOrPromise<number>) {
   }
 
   call(subscriber: Subscriber<T>): Subscriber<T> {
@@ -42,7 +42,7 @@ class DebounceSubscriber<T, R> extends OuterSubscriber<T, R> {
   private durationSubscription: Subscription = null;
 
   constructor(destination: Subscriber<R>,
-              private durationSelector: (value: T) => ObservableOrPromise<number>) {
+              private durationSelector: (value: T) => SubscribableOrPromise<number>) {
     super(destination);
   }
 
@@ -63,7 +63,7 @@ class DebounceSubscriber<T, R> extends OuterSubscriber<T, R> {
     this.destination.complete();
   }
 
-  private _tryNext(value: T, duration: ObservableOrPromise<number>): void {
+  private _tryNext(value: T, duration: SubscribableOrPromise<number>): void {
     let subscription = this.durationSubscription;
     this.value = value;
     this.hasValue = true;

src/operator/inspect.ts

@@ -1,6 +1,6 @@
 import {Operator} from '../Operator';
 import {Subscriber} from '../Subscriber';
-import {Observable, ObservableOrPromise} from '../Observable';
+import {Observable, SubscribableOrPromise} from '../Observable';
 import {Subscription} from '../Subscription';
 
 import {tryCatch} from '../util/tryCatch';
@@ -14,16 +14,16 @@ import {subscribeToResult} from '../util/subscribeToResult';
  * @method inspect
  * @owner Observable
  */
-export function inspect<T>(durationSelector: (value: T) => ObservableOrPromise<any>): Observable<T> {
+export function inspect<T>(durationSelector: (value: T) => SubscribableOrPromise<any>): Observable<T> {
   return this.lift(new InspectOperator(durationSelector));
 }
 
 export interface InspectSignature<T> {
-  (durationSelector: (value: T) => ObservableOrPromise<any>): Observable<T>;
+  (durationSelector: (value: T) => SubscribableOrPromise<any>): Observable<T>;
 }
 
 class InspectOperator<T> implements Operator<T, T> {
-  constructor(private durationSelector: (value: T) => ObservableOrPromise<any>) {
+  constructor(private durationSelector: (value: T) => SubscribableOrPromise<any>) {
   }
 
   call(subscriber: Subscriber<T>): Subscriber<T> {
@@ -38,7 +38,7 @@ class InspectSubscriber<T, R> extends OuterSubscriber<T, R> {
   private throttled: Subscription;
 
   constructor(destination: Subscriber<T>,
-              private durationSelector: (value: T) => ObservableOrPromise<any>) {
+              private durationSelector: (value: T) => SubscribableOrPromise<any>) {
     super(destination);
   }
 

src/operator/mergeMapTo.ts

@@ -1,4 +1,4 @@
-import {Observable, ObservableInput, ObservableOrPromise} from '../Observable';
+import {Observable, ObservableInput, SubscribableOrPromise} from '../Observable';
 import {Operator} from '../Operator';
 import {PartialObserver} from '../Observer';
 import {Subscriber} from '../Subscriber';
@@ -31,7 +31,7 @@ export interface MergeMapToSignature<T> {
 // TODO: Figure out correct signature here: an Operator<Observable<T>, R>
 //       needs to implement call(observer: Subscriber<R>): Subscriber<Observable<T>>
 export class MergeMapToOperator<T, I, R> implements Operator<Observable<T>, R> {
-  constructor(private ish: ObservableOrPromise<I>,
+  constructor(private ish: SubscribableOrPromise<I>,
               private resultSelector?: (outerValue: T, innerValue: I, outerIndex: number, innerIndex: number) => R,
               private concurrent: number = Number.POSITIVE_INFINITY) {
   }
@@ -48,7 +48,7 @@ export class MergeMapToSubscriber<T, I, R> extends OuterSubscriber<T, I> {
   protected index: number = 0;
 
   constructor(destination: Subscriber<R>,
-              private ish: ObservableOrPromise<I>,
+              private ish: SubscribableOrPromise<I>,
               private resultSelector?: (outerValue: T, innerValue: I, outerIndex: number, innerIndex: number) => R,
               private concurrent: number = Number.POSITIVE_INFINITY) {
     super(destination);

src/operator/throttle.ts

@@ -1,5 +1,5 @@
 import {Operator} from '../Operator';
-import {Observable, ObservableOrPromise} from '../Observable';
+import {Observable, SubscribableOrPromise} from '../Observable';
 import {Subscriber} from '../Subscriber';
 import {Subscription} from '../Subscription';
 
@@ -13,16 +13,16 @@ import {subscribeToResult} from '../util/subscribeToResult';
  * @method throttle
  * @owner Observable
  */
-export function throttle<T>(durationSelector: (value: T) => ObservableOrPromise<number>): Observable<T> {
+export function throttle<T>(durationSelector: (value: T) => SubscribableOrPromise<number>): Observable<T> {
   return this.lift(new ThrottleOperator(durationSelector));
 }
 
 export interface ThrottleSignature<T> {
-  (durationSelector: (value: T) => ObservableOrPromise<number>): Observable<T>;
+  (durationSelector: (value: T) => SubscribableOrPromise<number>): Observable<T>;
 }
 
 class ThrottleOperator<T> implements Operator<T, T> {
-  constructor(private durationSelector: (value: T) => ObservableOrPromise<number>) {
+  constructor(private durationSelector: (value: T) => SubscribableOrPromise<number>) {
   }
 
   call(subscriber: Subscriber<T>): Subscriber<T> {
@@ -34,7 +34,7 @@ class ThrottleSubscriber<T, R> extends OuterSubscriber<T, R> {
   private throttled: Subscription;
 
   constructor(protected destination: Subscriber<T>,
-              private durationSelector: (value: T) => ObservableOrPromise<number>) {
+              private durationSelector: (value: T) => SubscribableOrPromise<number>) {
     super(destination);
   }
 
@@ -45,7 +45,7 @@ class ThrottleSubscriber<T, R> extends OuterSubscriber<T, R> {
   }
 
   private tryDurationSelector(value: T): void {
-    let duration: ObservableOrPromise<number> = null;
+    let duration: SubscribableOrPromise<number> = null;
     try {
       duration = this.durationSelector(value);
     } catch (err) {
@@ -55,7 +55,7 @@ class ThrottleSubscriber<T, R> extends OuterSubscriber<T, R> {
     this.emitAndThrottle(value, duration);
   }
 
-  private emitAndThrottle(value: T, duration: ObservableOrPromise<number>) {
+  private emitAndThrottle(value: T, duration: SubscribableOrPromise<number>) {
     this.add(this.throttled = subscribeToResult(this, duration));
     this.destination.next(value);
   }