Extend the class library with the part of Spliterators that is used by Google Guava (#443)

Add class library support for the part of Spliterators that is used by Google Guava.

classlib/src/main/java/org/teavm/classlib/java/util/TSpliterators.java

@@ -0,0 +1,120 @@
+/*
+ *  Copyright 2017 Alexey Andreev.
+ *
+ *  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;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.function.Consumer;
+import java.util.function.IntConsumer;
+
+public class TSpliterators {
+
+    private TSpliterators() {
+    }
+
+    public static <T> TSpliterator<T> spliterator(Object[] array, int additionalCharacteristics) {
+        return new TSpliterator<T>() {
+            private int index;
+
+            @Override
+            public boolean tryAdvance(Consumer<? super T> action) {
+                if (index >= array.length) {
+                    return false;
+                }
+
+                action.accept((T) array[index]);
+                index++;
+                return true;
+            }
+
+            @Override
+            public TSpliterator<T> trySplit() {
+                return null;
+            }
+
+            @Override
+            public long estimateSize() {
+                return array.length;
+            }
+
+            @Override
+            public int characteristics() {
+                return additionalCharacteristics | TSpliterator.SIZED;
+            }
+        };
+    }
+
+    public static <T> TSpliterator<T> spliterator(Collection<? extends T> c, int characteristics) {
+        return ((TCollection) c).spliterator();
+    }
+
+    public static TSpliterator.OfInt spliterator(int[] array, int additionalCharacteristics) {
+        return spliterator(array, 0, array.length, additionalCharacteristics);
+    }
+
+    public static TSpliterator.OfInt spliterator(int[] array, int fromIndex, int toIndex,
+                                                 int additionalCharacteristics) {
+        return new TSpliterator.OfInt() {
+            int index = fromIndex;
+
+            @Override
+            public TSpliterator.OfInt trySplit() {
+                return null;
+            }
+
+            @Override
+            public boolean tryAdvance(IntConsumer action) {
+                if (index < toIndex) {
+                    action.accept(array[index]);
+                    index++;
+                    return true;
+                } else {
+                    return false;
+                }
+            }
+        };
+    }
+
+    public static <T> TSpliterator<T> spliterator(Iterator<? extends T> iterator,
+                                                  long size, int characteristics) {
+        return new TSpliterator<T>() {
+            @Override
+            public boolean tryAdvance(Consumer<? super T> action) {
+                if (iterator.hasNext()) {
+                    action.accept(iterator.next());
+                    return true;
+                } else {
+                    return false;
+                }
+            }
+
+            @Override
+            public TSpliterator<T> trySplit() {
+                return null;
+            }
+
+            @Override
+            public long estimateSize() {
+                return size;
+            }
+
+            @Override
+            public int characteristics() {
+                return characteristics;
+            }
+        };
+    }
+}

classlib/src/test/java/org/teavm/classlib/java/util/SpliteratorsTest.java

@@ -0,0 +1,98 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.IntConsumer;
+
+import org.junit.Test;
+
+public class SpliteratorsTest {
+
+    @Test
+    public void intSpliterator() {
+        int[] values = {1, 2, 3, 4, 5};
+
+        TSpliterator.OfInt spliterator = TSpliterators.spliterator(values, 0, 5, 0);
+
+        List<Integer> collected = new ArrayList<>();
+        IntConsumer collector = value -> collected.add((Integer) value);
+
+        assertTrue(spliterator.tryAdvance(collector));
+        assertTrue(spliterator.tryAdvance(collector));
+        assertTrue(spliterator.tryAdvance(collector));
+        assertTrue(spliterator.tryAdvance(collector));
+        assertTrue(spliterator.tryAdvance(collector));
+        assertFalse(spliterator.tryAdvance(collector));
+
+        assertEquals(Arrays.asList(1, 2, 3, 4, 5), collected);
+    }
+
+    @Test
+    public void intSpliteratorWithSubRange() {
+        int[] values = {1, 2, 3, 4, 5};
+
+        TSpliterator.OfInt spliterator = TSpliterators.spliterator(values, 1, 4, 0);
+
+        List<Integer> collected = new ArrayList<>();
+        IntConsumer collector = value -> collected.add((Integer) value);
+
+        assertTrue(spliterator.tryAdvance(collector));
+        assertTrue(spliterator.tryAdvance(collector));
+        assertTrue(spliterator.tryAdvance(collector));
+        assertFalse(spliterator.tryAdvance(collector));
+
+        assertEquals(Arrays.asList(2, 3, 4), collected);
+    }
+
+    @Test
+    public void spliteratorFromIterator() {
+        List<Integer> values = Arrays.asList(1, 2, 3);
+
+        TSpliterator<Integer> spliterator = TSpliterators.spliterator(values.iterator(),
+            values.size(), 0);
+
+        assertEquals(3L, spliterator.estimateSize());
+    }
+
+    @Test
+    public void spliteratorFromObjectArray() {
+        Object[] array = {1, 2, 3, 4};
+
+        TSpliterator<Integer> spliterator = TSpliterators.spliterator(array, 0);
+
+        List<Object> collected = new ArrayList<>();
+        Consumer<Object> collector = value -> collected.add(value);
+
+        spliterator.tryAdvance(collector);
+        spliterator.tryAdvance(collector);
+        array[2] = 9;
+        spliterator.tryAdvance(collector);
+        spliterator.tryAdvance(collector);
+        spliterator.tryAdvance(collector);
+
+        assertArrayEquals(new Object[] {1, 2, 9, 4}, array);
+        assertEquals(4L, spliterator.estimateSize());
+    }
+}