Merge pull request #1709 from motlin/collectKeysUnique

eclipse-collections-api/src/main/java/org/eclipse/collections/api/bimap/BiMap.java

@@ -77,6 +77,9 @@ public interface BiMap<K, V> extends MapIterable<K, V>
     @Override
     <R> BiMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> BiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     SetIterable<V> select(Predicate<? super V> predicate);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/bimap/ImmutableBiMap.java

@@ -84,6 +84,9 @@ public interface ImmutableBiMap<K, V> extends BiMap<K, V>, ImmutableMapIterable<
     @Override
     <R> ImmutableBiMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> ImmutableBiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     ImmutableSet<V> select(Predicate<? super V> predicate);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/bimap/MutableBiMap.java

@@ -85,6 +85,9 @@ public interface MutableBiMap<K, V> extends BiMap<K, V>, MutableMapIterable<K, V
     @Override
     <R> MutableBiMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> MutableBiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     MutableSet<V> select(Predicate<? super V> predicate);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/ImmutableMap.java

@@ -113,6 +113,9 @@ public interface ImmutableMap<K, V>
     @Override
     <R> ImmutableMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> ImmutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     <VV> ImmutableBag<VV> collect(Function<? super V, ? extends VV> function);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/ImmutableMapIterable.java

@@ -68,6 +68,9 @@ public interface ImmutableMapIterable<K, V> extends MapIterable<K, V>
     @Override
     <R> ImmutableMapIterable<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> ImmutableMapIterable<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     ImmutableCollection<V> select(Predicate<? super V> predicate);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/ImmutableOrderedMap.java

@@ -86,6 +86,9 @@ public interface ImmutableOrderedMap<K, V> extends OrderedMap<K, V>, ImmutableMa
     @Override
     <R> ImmutableOrderedMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> ImmutableOrderedMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     ImmutableOrderedMap<K, V> toReversed();
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/MapIterable.java

@@ -232,6 +232,16 @@ default V getOrDefault(Object key, V defaultValue)
      */
     <R> MapIterable<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    /**
+     * For each key and value of the map the function is evaluated. The results of these evaluations are returned in
+     * a new map. The map returned will use the keys projected from the function rather than the original keys.
+     *
+     * @throws IllegalStateException if the keys returned by the function are not unique
+     *
+     * @since 12.0
+     */
+    <R> MapIterable<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     /**
      * Return the first key and value of the map for which the predicate evaluates to true when they are given
      * as arguments. The predicate will only be evaluated until such pair is found or until all the keys and

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/MutableMap.java

@@ -85,6 +85,9 @@ <E> MutableMap<K, V> collectKeysAndValues(
     @Override
     <R> MutableMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> MutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     <K2, V2> MutableMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/MutableMapIterable.java

@@ -317,6 +317,9 @@ default void putAllMapIterable(MapIterable<? extends K, ? extends V> mapIterable
     @Override
     <R> MutableMapIterable<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> MutableMapIterable<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     MutableCollection<V> select(Predicate<? super V> predicate);
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/MutableOrderedMap.java

@@ -69,6 +69,9 @@ public interface MutableOrderedMap<K, V> extends OrderedMap<K, V>, MutableMapIte
     @Override
     <R> MutableOrderedMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> MutableOrderedMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     MutableOrderedMap<K, V> toReversed();
 

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/sorted/ImmutableSortedMap.java

@@ -41,6 +41,7 @@
 import org.eclipse.collections.api.list.primitive.ImmutableShortList;
 import org.eclipse.collections.api.map.ImmutableMap;
 import org.eclipse.collections.api.map.ImmutableMapIterable;
+import org.eclipse.collections.api.map.ImmutableOrderedMap;
 import org.eclipse.collections.api.map.MapIterable;
 import org.eclipse.collections.api.map.MutableMap;
 import org.eclipse.collections.api.multimap.list.ImmutableListMultimap;
@@ -142,6 +143,9 @@ default <R> ImmutableList<R> collectWithIndex(ObjectIntToObjectFunction<? super
     @Override
     <R> ImmutableSortedMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> ImmutableOrderedMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     <R> ImmutableList<R> collectIf(
             Predicate<? super V> predicate,

eclipse-collections-api/src/main/java/org/eclipse/collections/api/map/sorted/MutableSortedMap.java

@@ -41,6 +41,7 @@
 import org.eclipse.collections.api.map.MapIterable;
 import org.eclipse.collections.api.map.MutableMap;
 import org.eclipse.collections.api.map.MutableMapIterable;
+import org.eclipse.collections.api.map.MutableOrderedMap;
 import org.eclipse.collections.api.multimap.list.MutableListMultimap;
 import org.eclipse.collections.api.multimap.sortedset.MutableSortedSetMultimap;
 import org.eclipse.collections.api.partition.list.PartitionMutableList;
@@ -100,6 +101,9 @@ <E> MutableSortedMap<K, V> collectKeysAndValues(
     @Override
     <R> MutableSortedMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    <R> MutableOrderedMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     <R> MutableList<R> collect(Function<? super V, ? extends R> function);
 

eclipse-collections/src/main/java/org/eclipse/collections/impl/bimap/immutable/AbstractImmutableBiMap.java

@@ -264,6 +264,13 @@ public <R> ImmutableBiMap<K, R> collectValues(Function2<? super K, ? super V, ?
         return BiMaps.immutable.withAll(result);
     }
 
+    @Override
+    public <R> ImmutableBiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        ImmutableMap<R, V> result = this.delegate.collectKeysUnique(function);
+        return BiMaps.immutable.withAll(result);
+    }
+
     @Override
     public ImmutableBooleanBag collectBoolean(BooleanFunction<? super V> booleanFunction)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/bimap/mutable/AbstractMutableBiMap.java

@@ -486,6 +486,12 @@ public <R> HashBiMap<K, R> collectValues(Function2<? super K, ? super V, ? exten
         return result;
     }
 
+    @Override
+    public <R> MutableBiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return MapIterate.collectKeysUnique(this.delegate, function, BiMaps.mutable.empty());
+    }
+
     @Override
     public <VV> MutableBag<VV> collect(Function<? super V, ? extends VV> function)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/bimap/mutable/SynchronizedBiMap.java

@@ -122,6 +122,15 @@ public <R> MutableBiMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         }
     }
 
+    @Override
+    public <R> MutableBiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        synchronized (this.lock)
+        {
+            return this.getDelegate().collectKeysUnique(function);
+        }
+    }
+
     @Override
     public MutableSet<V> select(Predicate<? super V> predicate)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/bimap/mutable/UnmodifiableBiMap.java

@@ -569,6 +569,12 @@ public <R> MutableBiMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return this.delegate.collectValues(function);
     }
 
+    @Override
+    public <R> MutableBiMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return this.delegate.collectKeysUnique(function);
+    }
+
     @Override
     public BooleanIterable collectBoolean(BooleanFunction<? super V> booleanFunction)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/fixed/AbstractMemoryEfficientMutableMap.java

@@ -153,6 +153,9 @@ public FixedSizeMap<K, V> tap(Procedure<? super V> procedure)
     @Override
     public abstract <R> FixedSizeMap<K, R> collectValues(Function2<? super K, ? super V, ? extends R> function);
 
+    @Override
+    public abstract <R> FixedSizeMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function);
+
     @Override
     public abstract <K2, V2> FixedSizeMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function);
 

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/fixed/DoubletonMap.java

@@ -269,6 +269,22 @@ public <R> FixedSizeMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return Maps.fixedSize.of(this.key1, function.value(this.key1, this.value1), this.key2, function.value(this.key2, this.value2));
     }
 
+    @Override
+    public <R> FixedSizeMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        R key1 = function.value(this.key1, this.value1);
+        R key2 = function.value(this.key2, this.value2);
+        if (Objects.equals(key1, key2))
+        {
+            throw new IllegalStateException("Key " + key1 + " already exists in map!");
+        }
+        return Maps.fixedSize.of(
+                key1,
+                this.value1,
+                key2,
+                this.value2);
+    }
+
     @Override
     public <K2, V2> FixedSizeMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/fixed/EmptyMap.java

@@ -187,6 +187,12 @@ public <R> FixedSizeMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return Maps.fixedSize.of();
     }
 
+    @Override
+    public <R> FixedSizeMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return Maps.fixedSize.of();
+    }
+
     @Override
     public <K2, V2> FixedSizeMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/fixed/SingletonMap.java

@@ -232,6 +232,12 @@ public <R> FixedSizeMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return Maps.fixedSize.of(this.key1, function.value(this.key1, this.value1));
     }
 
+    @Override
+    public <R> FixedSizeMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return Maps.fixedSize.of(function.value(this.key1, this.value1), this.value1);
+    }
+
     @Override
     public <K2, V2> FixedSizeMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/fixed/TripletonMap.java

@@ -326,6 +326,33 @@ public <R> FixedSizeMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return Maps.fixedSize.of(this.key1, function.value(this.key1, this.value1), this.key2, function.value(this.key2, this.value2), this.key3, function.value(this.key3, this.value3));
     }
 
+    @Override
+    public <R> FixedSizeMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        R key1 = function.value(this.key1, this.value1);
+        R key2 = function.value(this.key2, this.value2);
+        if (Objects.equals(key1, key2))
+        {
+            throw new IllegalStateException("Key " + key1 + " already exists in map!");
+        }
+        R key3 = function.value(this.key3, this.value3);
+        if (Objects.equals(key1, key3))
+        {
+            throw new IllegalStateException("Key " + key1 + " already exists in map!");
+        }
+        if (Objects.equals(key2, key3))
+        {
+            throw new IllegalStateException("Key " + key2 + " already exists in map!");
+        }
+        return Maps.fixedSize.of(
+                key1,
+                this.value1,
+                key2,
+                this.value2,
+                key3,
+                this.value3);
+    }
+
     @Override
     public <K2, V2> FixedSizeMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/immutable/AbstractImmutableMap.java

@@ -240,6 +240,13 @@ public <R> ImmutableMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return result.toImmutable();
     }
 
+    @Override
+    public <R> ImmutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        UnifiedMap<R, V> result = MapIterate.collectKeysUnique(this, function, UnifiedMap.newMap(this.size()));
+        return result.toImmutable();
+    }
+
     @Override
     public ImmutableMap<K, V> select(Predicate2<? super K, ? super V> predicate)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/immutable/ImmutableEmptyMap.java

@@ -205,6 +205,12 @@ public <R> ImmutableMap<K, R> collectValues(Function2<? super K, ? super V, ? ex
         return Maps.immutable.empty();
     }
 
+    @Override
+    public <R> ImmutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return Maps.immutable.empty();
+    }
+
     @Override
     public Pair<K, V> detect(Predicate2<? super K, ? super V> predicate)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/mutable/AbstractMutableMap.java

@@ -107,6 +107,12 @@ public <R> MutableMap<K, R> collectValues(Function2<? super K, ? super V, ? exte
         return MapIterate.collectValues(this, function, this.newEmpty(this.size()));
     }
 
+    @Override
+    public <R> MutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return MapIterate.collectKeysUnique(this, function, this.newEmpty(this.size()));
+    }
+
     @Override
     public MutableMap<K, V> select(Predicate2<? super K, ? super V> predicate)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/mutable/SynchronizedMutableMap.java

@@ -260,6 +260,15 @@ public <R> MutableMap<K, R> collectValues(Function2<? super K, ? super V, ? exte
         }
     }
 
+    @Override
+    public <R> MutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        synchronized (this.lock)
+        {
+            return this.getDelegate().collectKeysUnique(function);
+        }
+    }
+
     @Override
     public MutableMap<K, V> tap(Procedure<? super V> procedure)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/mutable/UnmodifiableMutableMap.java

@@ -440,6 +440,12 @@ public <R> MutableMap<K, R> collectValues(Function2<? super K, ? super V, ? exte
         return this.getMutableMap().collectValues(function);
     }
 
+    @Override
+    public <R> MutableMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return this.getMutableMap().collectKeysUnique(function);
+    }
+
     @Override
     public <K2, V2> MutableMap<K2, V2> collect(Function2<? super K, ? super V, Pair<K2, V2>> function)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/ordered/immutable/ImmutableOrderedMapAdapter.java

@@ -314,6 +314,12 @@ public <R> ImmutableOrderedMap<K, R> collectValues(Function2<? super K, ? super
         return this.delegate.<R>collectValues(function).toImmutable();
     }
 
+    @Override
+    public <R> ImmutableOrderedMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return this.delegate.<R>collectKeysUnique(function).toImmutable();
+    }
+
     @Override
     public ImmutableOrderedMap<K, V> select(Predicate2<? super K, ? super V> predicate)
     {

eclipse-collections/src/main/java/org/eclipse/collections/impl/map/ordered/mutable/OrderedMapAdapter.java

@@ -454,6 +454,15 @@ public <R> MutableOrderedMap<K, R> collectValues(Function2<? super K, ? super V,
                 OrderedMapAdapter.adapt(new LinkedHashMap<>(this.size())));
     }
 
+    @Override
+    public <R> MutableOrderedMap<R, V> collectKeysUnique(Function2<? super K, ? super V, ? extends R> function)
+    {
+        return MapIterate.collectKeysUnique(
+                this,
+                function,
+                OrderedMapAdapter.adapt(new LinkedHashMap<>(this.size())));
+    }
+
     @Override
     public MutableOrderedMap<K, V> tap(Procedure<? super V> procedure)
     {