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Observable.concat: refactor varargs to overloads
ReactiveX#359 Varargs cause compiler warnings As part of this I also changed this: ```java public static <T> Observable<T> concat(Observable<Observable<? extends T>> observables) ``` to ```java public static <T> Observable<T> concat(Observable<Observable<T>> observables) ``` I documented the reasoning of this at ReactiveX#360 (comment)
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Lines changed: 352 additions & 14 deletions

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‎rxjava-core/src/main/java/rx/Observable.java‎

Lines changed: 222 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -979,14 +979,232 @@ public static <T> Observable<T> merge(Observable<? extends T>... source) {
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param source
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* a series of Observables
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* @param observables
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* an Observable of Observables
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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public static <T> Observable<T> concat(Observable<Observable<T>> observables) {
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return create(OperationConcat.concat(observables));
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}
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2) {
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return create(OperationConcat.concat(t1, t2));
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}
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3) {
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return create(OperationConcat.concat(t1, t2, t3));
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}
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* @param t4
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3, Observable<? extends T> t4) {
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return create(OperationConcat.concat(t1, t2, t3, t4));
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}
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* @param t4
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* an Observable to be concatenated
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* @param t5
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3, Observable<? extends T> t4, Observable<? extends T> t5) {
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return create(OperationConcat.concat(t1, t2, t3, t4, t5));
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}
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* @param t4
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* an Observable to be concatenated
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* @param t5
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* an Observable to be concatenated
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* @param t6
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3, Observable<? extends T> t4, Observable<? extends T> t5, Observable<? extends T> t6) {
1111+
return create(OperationConcat.concat(t1, t2, t3, t4, t5, t6));
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}
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* @param t4
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* an Observable to be concatenated
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* @param t5
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* an Observable to be concatenated
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* @param t6
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* an Observable to be concatenated
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* @param t7
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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public static <T> Observable<T> concat(Observable<? extends T>... source) {
989-
return create(OperationConcat.concat(source));
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3, Observable<? extends T> t4, Observable<? extends T> t5, Observable<? extends T> t6, Observable<? extends T> t7) {
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return create(OperationConcat.concat(t1, t2, t3, t4, t5, t6, t7));
1142+
}
1143+
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/**
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* Returns an Observable that emits the items emitted by two or more Observables, one after the
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* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
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*
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* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* @param t4
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* an Observable to be concatenated
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* @param t5
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* an Observable to be concatenated
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* @param t6
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* an Observable to be concatenated
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* @param t7
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* an Observable to be concatenated
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* @param t8
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
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* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
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*/
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@SuppressWarnings("unchecked")
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// suppress because the types are checked by the method signature before using a vararg
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public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3, Observable<? extends T> t4, Observable<? extends T> t5, Observable<? extends T> t6, Observable<? extends T> t7, Observable<? extends T> t8) {
1173+
return create(OperationConcat.concat(t1, t2, t3, t4, t5, t6, t7, t8));
1174+
}
1175+
1176+
/**
1177+
* Returns an Observable that emits the items emitted by two or more Observables, one after the
1178+
* other.
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* <p>
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* <img width="640" src="https://raw.github.com/wiki/Netflix/RxJava/images/rx-operators/concat.png">
1181+
*
1182+
* @param t1
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* an Observable to be concatenated
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* @param t2
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* an Observable to be concatenated
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* @param t3
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* an Observable to be concatenated
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* @param t4
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* an Observable to be concatenated
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* @param t5
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* an Observable to be concatenated
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* @param t6
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* an Observable to be concatenated
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* @param t7
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* an Observable to be concatenated
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* @param t8
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* an Observable to be concatenated
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* @param t9
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* an Observable to be concatenated
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* @return an Observable that emits items that are the result of combining the items emitted by
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* the {@code source} Observables, one after the other
1202+
* @see <a href="http://msdn.microsoft.com/en-us/library/system.reactive.linq.observable.concat(v=vs.103).aspx">MSDN: Observable.Concat Method</a>
1203+
*/
1204+
@SuppressWarnings("unchecked")
1205+
// suppress because the types are checked by the method signature before using a vararg
1206+
public static <T> Observable<T> concat(Observable<? extends T> t1, Observable<? extends T> t2, Observable<? extends T> t3, Observable<? extends T> t4, Observable<? extends T> t5, Observable<? extends T> t6, Observable<? extends T> t7, Observable<? extends T> t8, Observable<? extends T> t9) {
1207+
return create(OperationConcat.concat(t1, t2, t3, t4, t5, t6, t7, t8, t9));
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}
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/**

‎rxjava-core/src/main/java/rx/operators/OperationConcat.java‎

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Original file line numberDiff line numberDiff line change
@@ -60,7 +60,7 @@ public static <T> OnSubscribeFunc<T> concat(final Observable<? extends T>... seq
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return concat(Observable.from(sequences));
6161
}
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63-
public static <T> OnSubscribeFunc<T> concat(final List<? extends Observable<? extends T>> sequences) {
63+
public static <T> OnSubscribeFunc<T> concat(final Iterable<? extends Observable<? extends T>> sequences) {
6464
return concat(Observable.from(sequences));
6565
}
6666

‎rxjava-core/src/test/java/rx/ConcatTests.java‎

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package rx;
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import static org.junit.Assert.*;
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import java.util.Arrays;
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import java.util.List;
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import org.junit.Test;
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public class ConcatTests {
11+
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@Test
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public void testConcatSimple() {
14+
Observable<String> o1 = Observable.from("one", "two");
15+
Observable<String> o2 = Observable.from("three", "four");
16+
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List<String> values = Observable.concat(o1, o2).toList().toBlockingObservable().single();
18+
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assertEquals("one", values.get(0));
20+
assertEquals("two", values.get(1));
21+
assertEquals("three", values.get(2));
22+
assertEquals("four", values.get(3));
23+
}
24+
25+
@Test
26+
public void testConcatWithObservableOfObservable() {
27+
Observable<String> o1 = Observable.from("one", "two");
28+
Observable<String> o2 = Observable.from("three", "four");
29+
Observable<String> o3 = Observable.from("five", "six");
30+
31+
Observable<Observable<String>> os = Observable.from(o1, o2, o3);
32+
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List<String> values = Observable.concat(os).toList().toBlockingObservable().single();
34+
35+
assertEquals("one", values.get(0));
36+
assertEquals("two", values.get(1));
37+
assertEquals("three", values.get(2));
38+
assertEquals("four", values.get(3));
39+
}
40+
41+
@Test
42+
public void testConcatWithIterableOfObservable() {
43+
Observable<String> o1 = Observable.from("one", "two");
44+
Observable<String> o2 = Observable.from("three", "four");
45+
Observable<String> o3 = Observable.from("five", "six");
46+
47+
@SuppressWarnings("unchecked")
48+
Iterable<Observable<String>> is = Arrays.asList(o1, o2, o3);
49+
50+
List<String> values = Observable.concat(Observable.from(is)).toList().toBlockingObservable().single();
51+
52+
assertEquals("one", values.get(0));
53+
assertEquals("two", values.get(1));
54+
assertEquals("three", values.get(2));
55+
assertEquals("four", values.get(3));
56+
}
57+
}

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