classlib: add Stream dropWhile and takeWhile

This commit is contained in:
Ivan Hetman 2023-07-05 20:44:10 +03:00 committed by GitHub
parent ac2e5d6fa0
commit 61ef007672
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17 changed files with 411 additions and 0 deletions

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@ -81,6 +81,10 @@ public interface TDoubleStream extends TBaseStream<Double, TDoubleStream> {
TDoubleStream limit(long maxSize);
TDoubleStream takeWhile(DoublePredicate predicate);
TDoubleStream dropWhile(DoublePredicate predicate);
TDoubleStream skip(long n);
void forEach(DoubleConsumer action);

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@ -83,6 +83,10 @@ public interface TIntStream extends TBaseStream<Integer, TIntStream> {
TIntStream limit(long maxSize);
TIntStream takeWhile(IntPredicate predicate);
TIntStream dropWhile(IntPredicate predicate);
TIntStream skip(long n);
void forEach(IntConsumer action);

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@ -83,6 +83,10 @@ public interface TLongStream extends TBaseStream<Long, TLongStream> {
TLongStream limit(long maxSize);
TLongStream takeWhile(LongPredicate predicate);
TLongStream dropWhile(LongPredicate predicate);
TLongStream skip(long n);
void forEach(LongConsumer action);

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@ -119,6 +119,8 @@ public interface TStream<T> extends TBaseStream<T, TStream<T>> {
TStream<T> takeWhile(Predicate<? super T> predicate);
TStream<T> dropWhile(Predicate<? super T> predicate);
TStream<T> skip(long n);
void forEach(Consumer<? super T> action);

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@ -0,0 +1,44 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.doubleimpl;
import java.util.function.DoublePredicate;
public class TDropWhileDoubleStream extends TWrappingDoubleStreamImpl {
private DoublePredicate predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is true */
private boolean isStarted;
TDropWhileDoubleStream(TSimpleDoubleStreamImpl innerStream, DoublePredicate predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected DoublePredicate wrap(DoublePredicate consumer) {
return t -> {
if (!isStarted) {
if (predicate.test(t)) {
return true;
} else {
isStarted = true;
}
}
return consumer.test(t);
};
}
}

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@ -90,6 +90,16 @@ public abstract class TSimpleDoubleStreamImpl implements TDoubleStream {
return new TLimitingDoubleStreamImpl(this, (int) maxSize);
}
@Override
public TDoubleStream takeWhile(DoublePredicate predicate) {
return new TTakeWhileDoubleStream(this, predicate);
}
@Override
public TDoubleStream dropWhile(DoublePredicate predicate) {
return new TDropWhileDoubleStream(this, predicate);
}
@Override
public TDoubleStream skip(long n) {
return new TSkippingDoubleStreamImpl(this, (int) n);

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@ -0,0 +1,46 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.doubleimpl;
import java.util.function.DoublePredicate;
public class TTakeWhileDoubleStream extends TWrappingDoubleStreamImpl {
private DoublePredicate predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is false */
private boolean isStopped;
TTakeWhileDoubleStream(TSimpleDoubleStreamImpl innerStream, DoublePredicate predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected DoublePredicate wrap(DoublePredicate consumer) {
return t -> {
if (isStopped) {
return false;
}
if (predicate.test(t)) {
return consumer.test(t);
} else {
isStopped = true;
return false;
}
};
}
}

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@ -0,0 +1,44 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.impl;
import java.util.function.Predicate;
public class TDropWhileStream<T> extends TWrappingStreamImpl<T, T> {
private Predicate<? super T> predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is true */
private boolean isStarted;
TDropWhileStream(TSimpleStreamImpl<T> innerStream, Predicate<? super T> predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected Predicate<T> wrap(Predicate<? super T> consumer) {
return t -> {
if (!isStarted) {
if (predicate.test(t)) {
return true;
} else {
isStarted = true;
}
}
return consumer.test(t);
};
}
}

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@ -116,6 +116,11 @@ public abstract class TSimpleStreamImpl<T> implements TStream<T> {
return new TTakeWhileStream<>(this, predicate);
}
@Override
public TStream<T> dropWhile(Predicate<? super T> predicate) {
return new TDropWhileStream<>(this, predicate);
}
@Override
public TStream<T> skip(long n) {
return new TSkippingStreamImpl<>(this, (int) n);

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@ -0,0 +1,44 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.intimpl;
import java.util.function.IntPredicate;
public class TDropWhileIntStream extends TWrappingIntStreamImpl {
private IntPredicate predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is true */
private boolean isStarted;
TDropWhileIntStream(TSimpleIntStreamImpl innerStream, IntPredicate predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected IntPredicate wrap(IntPredicate consumer) {
return t -> {
if (!isStarted) {
if (predicate.test(t)) {
return true;
} else {
isStarted = true;
}
}
return consumer.test(t);
};
}
}

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@ -91,6 +91,16 @@ public abstract class TSimpleIntStreamImpl implements TIntStream {
return new TLimitingIntStreamImpl(this, (int) maxSize);
}
@Override
public TIntStream takeWhile(IntPredicate predicate) {
return new TTakeWhileIntStream(this, predicate);
}
@Override
public TIntStream dropWhile(IntPredicate predicate) {
return new TDropWhileIntStream(this, predicate);
}
@Override
public TIntStream skip(long n) {
return new TSkippingIntStreamImpl(this, (int) n);

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@ -0,0 +1,46 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.intimpl;
import java.util.function.IntPredicate;
public class TTakeWhileIntStream extends TWrappingIntStreamImpl {
private IntPredicate predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is false */
private boolean isStopped;
TTakeWhileIntStream(TSimpleIntStreamImpl innerStream, IntPredicate predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected IntPredicate wrap(IntPredicate consumer) {
return t -> {
if (isStopped) {
return false;
}
if (predicate.test(t)) {
return consumer.test(t);
} else {
isStopped = true;
return false;
}
};
}
}

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@ -0,0 +1,44 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.longimpl;
import java.util.function.LongPredicate;
public class TDropWhileLongStream extends TWrappingLongStreamImpl {
private LongPredicate predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is true */
private boolean isStarted;
TDropWhileLongStream(TSimpleLongStreamImpl innerStream, LongPredicate predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected LongPredicate wrap(LongPredicate consumer) {
return t -> {
if (!isStarted) {
if (predicate.test(t)) {
return true;
} else {
isStarted = true;
}
}
return consumer.test(t);
};
}
}

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@ -91,6 +91,16 @@ public abstract class TSimpleLongStreamImpl implements TLongStream {
return new TLimitingLongStreamImpl(this, (int) maxSize);
}
@Override
public TLongStream takeWhile(LongPredicate predicate) {
return new TTakeWhileLongStream(this, predicate);
}
@Override
public TLongStream dropWhile(LongPredicate predicate) {
return new TDropWhileLongStream(this, predicate);
}
@Override
public TLongStream skip(long n) {
return new TSkippingLongStreamImpl(this, (int) n);

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@ -0,0 +1,46 @@
/*
* Copyright 2023 ihromant.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.teavm.classlib.java.util.stream.longimpl;
import java.util.function.LongPredicate;
public class TTakeWhileLongStream extends TWrappingLongStreamImpl {
private LongPredicate predicate;
/* set to `true` as soon as we see a value `v` in the source stream for which `predicate.test(v)` is false */
private boolean isStopped;
TTakeWhileLongStream(TSimpleLongStreamImpl innerStream, LongPredicate predicate) {
super(innerStream);
this.predicate = predicate;
}
@Override
protected LongPredicate wrap(LongPredicate consumer) {
return t -> {
if (isStopped) {
return false;
}
if (predicate.test(t)) {
return consumer.test(t);
} else {
isStopped = true;
return false;
}
};
}
}

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@ -108,6 +108,34 @@ public class IntStreamTest {
}
}
@Test
public void takeWhileWorks() {
assertArrayEquals(new int[] { 1, 2, 3 },
IntStream.of(1, 2, 3, 4, 0, 5, 6).takeWhile(n -> n < 4).toArray());
}
@Test
public void dropWhileWorks() {
assertArrayEquals(new int[] { 4, 0, 5, 6 },
IntStream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(n -> n < 4).toArray());
assertArrayEquals(new int[] {},
IntStream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(n -> n < 7).toArray());
}
@Test
public void takeWhileWithOtherStreamOps() {
assertArrayEquals(new int[] { 1, 3 },
IntStream.of(1, 2, 3, 4, 0, 5, 6).takeWhile(i -> i < 4).filter(i -> i % 2 != 0).toArray());
}
@Test
public void dropWhileWithOtherStreamOps() {
assertArrayEquals(new int[] { 4, 0, 6 },
IntStream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(i -> i < 4).filter(i -> i % 2 == 0).toArray());
assertArrayEquals(new int[] {},
IntStream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(i -> i < 7).filter(i -> i % 2 == 0).toArray());
}
@Test
public void limitWorks() {
for (int i = 0; i <= 3; ++i) {

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@ -396,6 +396,16 @@ public class StreamTest {
assertEquals("123", sb.toString());
}
@Test
public void dropWhileWorks() {
var sb = new StringBuilder();
Stream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(n -> n < 4).forEach(sb::append);
assertEquals("4056", sb.toString());
sb = new StringBuilder();
Stream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(n -> n < 7).forEach(sb::append);
assertEquals("", sb.toString());
}
@Test
public void takeWhileWithOtherStreamOps() {
var sb = new StringBuilder();
@ -403,6 +413,16 @@ public class StreamTest {
assertEquals("13", sb.toString());
}
@Test
public void dropWhileWithOtherStreamOps() {
var sb = new StringBuilder();
Stream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(i -> i < 4).filter(i -> i % 2 == 0).forEach(sb::append);
assertEquals("406", sb.toString());
sb = new StringBuilder();
Stream.of(1, 2, 3, 4, 0, 5, 6).dropWhile(i -> i < 7).filter(i -> i % 2 == 0).forEach(sb::append);
assertEquals("", sb.toString());
}
@Test
public void toList() {
List<Integer> list = Stream.of(1, 2, 3, 4, 5).filter(i -> i % 2 == 0).toList();