Pull up implementations of aggregateBy() as default methods.

Signed-off-by: Craig P. Motlin <cmotlin@gmail.com>
eclipse · Jul 2, 2020 · 1e3713a · 1e3713a
1 parent bfb3b76
commit 1e3713a
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diff --git a/...e-collections-api/src/main/java/org/eclipse/collections/api/bag/ImmutableBagIterable.java b/...e-collections-api/src/main/java/org/eclipse/collections/api/bag/ImmutableBagIterable.java
@@ -11,12 +11,17 @@
 package org.eclipse.collections.api.bag;
 
 import org.eclipse.collections.api.block.function.Function;
+import org.eclipse.collections.api.block.function.Function0;
+import org.eclipse.collections.api.block.function.Function2;
 import org.eclipse.collections.api.block.function.primitive.ObjectIntToObjectFunction;
 import org.eclipse.collections.api.block.predicate.Predicate;
 import org.eclipse.collections.api.block.predicate.Predicate2;
 import org.eclipse.collections.api.block.predicate.primitive.IntPredicate;
 import org.eclipse.collections.api.block.procedure.Procedure;
 import org.eclipse.collections.api.collection.ImmutableCollection;
+import org.eclipse.collections.api.factory.Maps;
+import org.eclipse.collections.api.map.ImmutableMap;
+import org.eclipse.collections.api.map.MutableMap;
 import org.eclipse.collections.api.map.MutableMapIterable;
 import org.eclipse.collections.api.multimap.bag.ImmutableBagIterableMultimap;
 import org.eclipse.collections.api.partition.bag.PartitionImmutableBagIterable;
@@ -81,4 +86,22 @@ default ImmutableBagIterable<T> selectDuplicates()
 
     @Override
     <V> ImmutableCollection<V> collectWithOccurrences(ObjectIntToObjectFunction<? super T, ? extends V> function);
+
+    @Override
+    default <K, V> ImmutableMap<K, V> aggregateBy(
+            Function<? super T, ? extends K> groupBy,
+            Function0<? extends V> zeroValueFactory,
+            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator)
+    {
+        MutableMap<K, V> result = Maps.mutable.empty();
+        this.forEachWithOccurrences((each, occurrences) ->
+        {
+            K key = groupBy.valueOf(each);
+            for (int i = 0; i < occurrences; i++)
+            {
+                result.updateValueWith(key, zeroValueFactory, nonMutatingAggregator, each);
+            }
+        });
+        return result.toImmutable();
+    }
 }
diff --git a/...pse-collections-api/src/main/java/org/eclipse/collections/api/bag/MutableBagIterable.java b/...pse-collections-api/src/main/java/org/eclipse/collections/api/bag/MutableBagIterable.java
@@ -12,13 +12,17 @@
 
 import org.eclipse.collections.api.RichIterable;
 import org.eclipse.collections.api.block.function.Function;
+import org.eclipse.collections.api.block.function.Function0;
+import org.eclipse.collections.api.block.function.Function2;
 import org.eclipse.collections.api.block.function.primitive.ObjectIntToObjectFunction;
 import org.eclipse.collections.api.block.predicate.Predicate;
 import org.eclipse.collections.api.block.predicate.Predicate2;
 import org.eclipse.collections.api.block.predicate.primitive.IntPredicate;
 import org.eclipse.collections.api.block.procedure.Procedure;
 import org.eclipse.collections.api.collection.MutableCollection;
+import org.eclipse.collections.api.factory.Maps;
 import org.eclipse.collections.api.list.MutableList;
+import org.eclipse.collections.api.map.MutableMap;
 import org.eclipse.collections.api.map.MutableMapIterable;
 import org.eclipse.collections.api.multimap.bag.MutableBagIterableMultimap;
 import org.eclipse.collections.api.partition.bag.PartitionMutableBagIterable;
@@ -143,4 +147,22 @@ default MutableBagIterable<T> withoutAll(Iterable<? extends T> elements)
 
     @Override
     <V> RichIterable<V> collectWithOccurrences(ObjectIntToObjectFunction<? super T, ? extends V> function);
+
+    @Override
+    default <K, V> MutableMap<K, V> aggregateBy(
+            Function<? super T, ? extends K> groupBy,
+            Function0<? extends V> zeroValueFactory,
+            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator)
+    {
+        MutableMap<K, V> result = Maps.mutable.empty();
+        this.forEachWithOccurrences((each, occurrences) ->
+        {
+            K key = groupBy.valueOf(each);
+            for (int i = 0; i < occurrences; i++)
+            {
+                result.updateValueWith(key, zeroValueFactory, nonMutatingAggregator, each);
+            }
+        });
+        return result;
+    }
 }