添加 toMap 重载, 重复 value 合并

timandy · Nov 28, 2023 · 81ceb58 · 81ceb58
1 parent f83b7fa
commit 81ceb58
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diff --git a/src/main/java/com/bestvike/linq/IEnumerable.java b/src/main/java/com/bestvike/linq/IEnumerable.java
@@ -1117,6 +1117,10 @@ default <TKey, TElement> Map<TKey, TElement> toLinkedMap(Func1<? super TSource,
         return ToCollection.toLinkedMap(this, (Func1<TSource, TKey>) keySelector, (Func1<TSource, TElement>) elementSelector);
     }
 
+    default <TKey, TElement> Map<TKey, TElement> toLinkedMap(Func1<? super TSource, ? extends TKey> keySelector, Func1<? super TSource, ? extends TElement> elementSelector, Func2<? super TElement,? super TElement,? extends TElement> resultElementSelector) {
+        return ToCollection.toLinkedMap(this, (Func1<TSource, TKey>) keySelector, (Func1<TSource, TElement>) elementSelector, (Func2< TElement, TElement, TElement>) resultElementSelector);
+    }
+
     default Set<TSource> toLinkedSet() {
         return ToCollection.toLinkedSet(this);
     }
@@ -1149,6 +1153,10 @@ default <TKey, TElement> Map<TKey, TElement> toMap(Func1<? super TSource, ? exte
         return ToCollection.toMap(this, (Func1<TSource, TKey>) keySelector, (Func1<TSource, TElement>) elementSelector);
     }
 
+    default <TKey, TElement> Map<TKey, TElement> toMap(Func1<? super TSource, ? extends TKey> keySelector, Func1<? super TSource, ? extends TElement> elementSelector, Func2<? super TElement,? super TElement,? extends TElement> resultElementSelector) {
+        return ToCollection.toMap(this, (Func1<TSource, TKey>) keySelector, (Func1<TSource, TElement>) elementSelector, (Func2< TElement, TElement, TElement>) resultElementSelector);
+    }
+
     default Set<TSource> toSet() {
         return ToCollection.toSet(this);
     }

diff --git a/src/main/java/com/bestvike/linq/enumerable/ToCollection.java b/src/main/java/com/bestvike/linq/enumerable/ToCollection.java
@@ -4,6 +4,7 @@
 import com.bestvike.collections.generic.ICollection;
 import com.bestvike.function.Action2;
 import com.bestvike.function.Func1;
+import com.bestvike.function.Func2;
 import com.bestvike.linq.IEnumerable;
 import com.bestvike.linq.IEnumerator;
 import com.bestvike.linq.exception.ExceptionArgument;
@@ -183,6 +184,52 @@ public static <TSource, TKey, TElement> Map<TKey, TElement> toMap(IEnumerable<TS
         return map;
     }
 
+    public static <TSource, TKey, TElement> Map<TKey, TElement> toMap(IEnumerable<TSource> source, Func1<TSource, TKey> keySelector, Func1<TSource, TElement> elementSelector, Func2<TElement, TElement, TElement> resultElementSelector) {
+        if (source == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.source);
+        if (keySelector == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.keySelector);
+        if (elementSelector == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.elementSelector);
+        if (resultElementSelector == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.resultElementSelector);
+
+        if (source instanceof ICollection) {
+            ICollection<TSource> collection = (ICollection<TSource>) source;
+            int capacity = collection._getCount();
+            if (capacity == 0)
+                return new HashMap<>();
+
+            if (collection instanceof IArrayList) {
+                IArrayList<TSource> list = (IArrayList<TSource>) collection;
+                Map<TKey, TElement> map = new HashMap<>(initialCapacity(capacity));
+                for (int i = 0; i < capacity; i++) {
+                    TSource element = list.get(i);
+                    map.merge(keySelector.apply(element), elementSelector.apply(element), resultElementSelector::apply);
+                }
+                return map;
+            }
+
+            Map<TKey, TElement> map = new HashMap<>(initialCapacity(capacity));
+            try (IEnumerator<TSource> e = source.enumerator()) {
+                while (e.moveNext()) {
+                    TSource element = e.current();
+                    map.merge(keySelector.apply(element), elementSelector.apply(element), resultElementSelector::apply);
+                }
+            }
+            return map;
+        }
+
+        Map<TKey, TElement> map = new HashMap<>();
+        try (IEnumerator<TSource> e = source.enumerator()) {
+            while (e.moveNext()) {
+                TSource element = e.current();
+                map.merge(keySelector.apply(element), elementSelector.apply(element), resultElementSelector::apply);
+            }
+        }
+        return map;
+    }
+
     public static <TSource, TKey> Map<TKey, TSource> toLinkedMap(IEnumerable<TSource> source, Func1<TSource, TKey> keySelector) {
         if (source == null)
             ThrowHelper.throwArgumentNullException(ExceptionArgument.source);
@@ -269,6 +316,50 @@ public static <TSource, TKey, TElement> Map<TKey, TElement> toLinkedMap(IEnumera
         return map;
     }
 
+    public static <TSource, TKey, TElement> Map<TKey, TElement> toLinkedMap(IEnumerable<TSource> source, Func1<TSource, TKey> keySelector, Func1<TSource, TElement> elementSelector, Func2<TElement, TElement, TElement> resultElementSelector) {
+        if (source == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.source);
+        if (keySelector == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.keySelector);
+        if (elementSelector == null)
+            ThrowHelper.throwArgumentNullException(ExceptionArgument.elementSelector);
+
+        if (source instanceof ICollection) {
+            ICollection<TSource> collection = (ICollection<TSource>) source;
+            int capacity = collection._getCount();
+            if (capacity == 0)
+                return new LinkedHashMap<>();
+
+            if (collection instanceof IArrayList) {
+                IArrayList<TSource> list = (IArrayList<TSource>) collection;
+                Map<TKey, TElement> map = new LinkedHashMap<>(initialCapacity(capacity));
+                for (int i = 0; i < capacity; i++) {
+                    TSource element = list.get(i);
+                    map.merge(keySelector.apply(element), elementSelector.apply(element), resultElementSelector::apply);
+                }
+                return map;
+            }
+
+            Map<TKey, TElement> map = new LinkedHashMap<>(initialCapacity(capacity));
+            try (IEnumerator<TSource> e = source.enumerator()) {
+                while (e.moveNext()) {
+                    TSource element = e.current();
+                    map.merge(keySelector.apply(element), elementSelector.apply(element), resultElementSelector::apply);
+                }
+            }
+            return map;
+        }
+
+        Map<TKey, TElement> map = new LinkedHashMap<>();
+        try (IEnumerator<TSource> e = source.enumerator()) {
+            while (e.moveNext()) {
+                TSource element = e.current();
+                map.merge(keySelector.apply(element), elementSelector.apply(element), resultElementSelector::apply);
+            }
+        }
+        return map;
+    }
+
     public static <TSource> Set<TSource> toSet(IEnumerable<TSource> source) {
         if (source == null)
             ThrowHelper.throwArgumentNullException(ExceptionArgument.source);

diff --git a/src/main/java/com/bestvike/linq/exception/ExceptionArgument.java b/src/main/java/com/bestvike/linq/exception/ExceptionArgument.java
@@ -47,6 +47,7 @@ public enum ExceptionArgument {
     options,
     other,
     range,
+    resultElementSelector,
     start,
     startIndex,
     value,

diff --git a/src/test/java/com/bestvike/linq/enumerable/ToLinkedMapTest.java b/src/test/java/com/bestvike/linq/enumerable/ToLinkedMapTest.java
@@ -315,6 +315,19 @@ void testToMapWithSelector() {
         assertEquals(2, map2.size());
     }
 
+    @Test
+    void testToMapWithResultElementSelector() {
+        Map<Integer, String> map = Linq.of(emps).toLinkedMap(emp -> emp.empno, emp -> emp.name,(x,y)->x);
+        assertTrue(map.get(110).equals("Bill"));
+        assertEquals(4, map.size());
+
+        //key 重复,保留第一个
+        Map<Integer, String> map2 = Linq.of(emps).toLinkedMap(emp -> emp.deptno, emp -> emp.name,(x,y)->y);
+        assertEquals(emps[3].name, map2.get(10));
+        assertEquals(emps[1].name, map2.get(30));
+        assertEquals(2, map2.size());
+    }
+
 
     private static class NameScore extends ValueType {
         private final String Name;

diff --git a/src/test/java/com/bestvike/linq/enumerable/ToMapTest.java b/src/test/java/com/bestvike/linq/enumerable/ToMapTest.java
@@ -315,6 +315,19 @@ void testToMapWithSelector() {
         assertEquals(2, map2.size());
     }
 
+    @Test
+    void testToMapWithResultElementSelector() {
+        Map<Integer, String> map = Linq.of(emps).toMap(emp -> emp.empno, emp -> emp.name, (x, y) -> x);
+        assertTrue(map.get(110).equals("Bill"));
+        assertEquals(4, map.size());
+
+        //key 重复,保留第一个
+        Map<Integer, String> map2 = Linq.of(emps).toMap(emp -> emp.deptno, emp -> emp.name, (x, y) -> y);
+        assertEquals(emps[3].name, map2.get(10));
+        assertEquals(emps[1].name, map2.get(30));
+        assertEquals(2, map2.size());
+    }
+
 
     private static class NameScore extends ValueType {
         private final String Name;
-Original file line number
+Diff line change
@@ Expand Up / @@ -47,6 +47,7 @@ public enum ExceptionArgument { @@
         options,
         other,
         range,
+        resultElementSelector,
         start,
         startIndex,
         value,
@@ Expand Down @@