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The module for FunctionalJ Core.
// ============================================================================
// Copyright (c) 2017-2021 Nawapunth Manusitthipol (NawaMan - http://nawaman.net).
// ----------------------------------------------------------------------------
// MIT License
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
// ============================================================================
package functionalj.stream;
import static functionalj.function.FuncUnit0.funcUnit0;
import static functionalj.stream.ZipWithOption.AllowUnpaired;
import static functionalj.stream.ZipWithOption.RequireBoth;
import java.util.Iterator;
import java.util.function.BiFunction;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import functionalj.result.NoMoreResultException;
import functionalj.tuple.Tuple2;
import lombok.val;
public interface StreamPlusWithCombine {
public StreamPlus streamPlus();
/** Concatenate the given head stream in front of this stream. */
public default StreamPlus prependWith(Stream head) {
return StreamPlus.concat(
StreamPlus.from(head),
streamPlus());
}
/** Concatenate the given tail stream to this stream. */
public default StreamPlus appendWith(Stream tail) {
return StreamPlus.concat(
streamPlus(),
StreamPlus.from(tail));
}
/**
* Merge this with another stream by alternatively picking value from the each stream.
* If one stream ended before another one, the rest of the value will be appended.
*
* For an example:
* This stream: [A, B, C]
* Another stream: [1, 2, 3, 4, 5]
* Result stream: [A, 1, B, 2, C, 3, 4, 5]
*/
public default StreamPlus mergeWith(Stream anotherStream) {
val streamPlus = streamPlus();
val iteratorA = streamPlus.iterator();
val iteratorB = StreamPlus.from(anotherStream).iterator();
val resultStream
= StreamPlusHelper
.doMerge(iteratorA, iteratorB);
resultStream
.onClose(()->{
funcUnit0(()->streamPlus .close()).runCarelessly();
funcUnit0(()->anotherStream.close()).runCarelessly();
});
return resultStream;
}
//-- Zip --
/**
* Combine this stream with another stream into a stream of tuple pair.
* The combination stops when any of the stream ended.
*
* For an example:
* This stream: [A, B, C]
* Another stream: [1, 2, 3, 4, 5]
* Result stream: [(A, 1), (B, 2), (C, 3)]
*/
public default StreamPlus> zipWith(Stream anotherStream) {
return zipWith(anotherStream, RequireBoth, Tuple2::of);
}
/**
* Combine this stream with another stream into a stream of tuple pair.
* Depending on the given ZipWithOption, the combination may ended when one ended or continue with null as value.
*
* For an example with ZipWithOption.AllowUnpaired:
* This stream: [A, B, C]
* Another stream: [1, 2, 3, 4, 5]
* Result stream: [(A, 1), (B, 2), (C, 3), (null, 4), (null, 5)]
*/
public default StreamPlus> zipWith(
Stream anotherStream,
ZipWithOption option) {
return zipWith(anotherStream, option, Tuple2::of);
}
/**
* Combine this stream with another stream using the combinator to create the result value one by one.
* The combination stops when any of the stream ended.
*
* For an example:
* This stream: [A, B, C]
* Another stream: [1, 2, 3, 4, 5]
* Combinator: (v1,v2) -> v1 + "-" + v2
* Result stream: [A-1, B-2, C-3]
*/
public default StreamPlus zipWith(
Stream anotherStream,
BiFunction combinator) {
return zipWith(anotherStream, RequireBoth, combinator);
}
/**
* Combine this stream with another stream using the combinator to create the result value one by one.
* Depending on the given ZipWithOption, the combination may ended when one ended or continue with null as value.
*
* For an example with ZipWithOption.AllowUnpaired:
* This stream: [A, B, C]
* Another stream: [1, 2, 3, 4, 5]
* Combinator: (v1,v2) -> v1 + "-" + v2
* Result stream: [A-1, B-2, C-3, null-4, null-5]
*/
public default StreamPlus zipWith(
Stream anotherStream,
ZipWithOption option,
BiFunction combinator) {
val iteratorA = streamPlus().iterator();
val iteratorB = IteratorPlus.from(anotherStream.iterator());
return StreamPlusHelper.doZipWith(option, combinator, iteratorA, iteratorB);
}
/**
* Create a new stream by choosing value from each stream using the selector.
* The value from the longer stream is automatically used after the shorter stream ended.
*
* For an example:
* This stream: [10, 1, 9, 2]
* Another stream: [ 5, 5, 5, 5, 5, 5, 5]
* Selector: (v1,v2) -> v1 > v2
* Result stream: [10, 5, 9, 5]
*/
public default StreamPlus choose(
Stream anotherStream,
BiFunction selectThisNotAnother) {
return choose(anotherStream, AllowUnpaired, selectThisNotAnother);
}
/**
* Create a new stream by choosing value from each stream using the selector.
* The value from the longer stream is automatically used after the shorter stream ended.
*
* For an example:
* This stream: [10, 1, 9, 2]
* Another stream: [ 5, 5, 5, 5, 5, 5, 5]
* Selector: (v1,v2) -> v1 > v2
* Result stream: [10, 5, 9, 5]
*/
public default StreamPlus choose(
Stream anotherStream,
ZipWithOption option,
BiFunction selectThisNotAnother) {
val iteratorA = this.streamPlus().iterator();
val iteratorB = anotherStream.iterator();
val iterator = new Iterator() {
private boolean hasNextA;
private boolean hasNextB;
public boolean hasNext() {
hasNextA = iteratorA.hasNext();
hasNextB = iteratorB.hasNext();
return (option == ZipWithOption.RequireBoth)
? (hasNextA && hasNextB)
: (hasNextA || hasNextB);
}
public DATA next() {
val nextA = hasNextA ? iteratorA.next() : null;
val nextB = hasNextB ? iteratorB.next() : null;
if (hasNextA && hasNextB) {
boolean selectA = selectThisNotAnother.apply(nextA, nextB);
return selectA ? nextA : nextB;
}
if (hasNextA) {
return nextA;
}
if (hasNextB) {
return nextB;
}
throw new NoMoreResultException();
}
};
val iterable = new Iterable() {
@Override
public Iterator iterator() {
return iterator;
}
};
return StreamPlus.from(StreamSupport.stream(iterable.spliterator(), false));
}
}