Fix PersistentMap hashCode implementation

Author: Abduqodiri Qurbonzoda

kotlinx-collections-immutable/src/main/kotlin/kotlinx/collections/immutable/implementations/immutableMap/PersistentHashMapBuilderContentIterators.kt

@@ -28,11 +28,13 @@ internal class TrieNodeMutableEntriesIterator<K, V>(private val builder: Persist
 }
 
 private class MutableMapEntry<K, V>(private val builder: PersistentHashMapBuilder<K, V>,
-                                    override val key: K,
-                                    override val value: V) : MutableMap.MutableEntry<K, V> {
+                                    key: K,
+                                    override var value: V) : MapEntry<K, V>(key, value), MutableMap.MutableEntry<K, V> {
     override fun setValue(newValue: V): V {
+        val result = value
+        value = newValue
         builder[key] = newValue
-        return value
+        return result
     }
 }
 

kotlinx-collections-immutable/src/main/kotlin/kotlinx/collections/immutable/implementations/immutableMap/PersistentHashMapContentIterators.kt

@@ -75,7 +75,13 @@ internal class TrieNodeEntriesIterator<out K, out V> : TrieNodeBaseIterator<K, V
     }
 }
 
-private class MapEntry<out K, out V>(override val key: K, override val value: V) : Map.Entry<K, V>
+internal open class MapEntry<out K, out V>(override val key: K, override val value: V) : Map.Entry<K, V> {
+    override fun hashCode(): Int = key.hashCode() xor value.hashCode()
+    override fun equals(other: Any?): Boolean =
+            (other as? Map.Entry<*, *>)?.let { it.key == key && it.value == value } ?: false
+
+    override fun toString(): String = key.toString() + "=" + value.toString()
+}
 
 
 internal abstract class PersistentHashMapBaseIterator<K, V, T>(node: TrieNode<K, V>,

kotlinx-collections-immutable/src/main/kotlin/kotlinx/collections/immutable/implementations/persistentOrderedMap/PersistentOrderedMapBuilderContentIterators.kt

@@ -16,6 +16,8 @@
 
 package kotlinx.collections.immutable.implementations.persistentOrderedMap
 
+import kotlinx.collections.immutable.implementations.immutableMap.MapEntry
+
 internal open class PersistentOrderedMapBuilderLinksIterator<K, V>(internal var nextKey: K?,
                                                                    internal val map: MutableMap<K, Links<K, V>>) : MutableIterator<Links<K, V>> {
     internal var lastProcessedKey: K? = null
@@ -66,9 +68,9 @@ internal class PersistentOrderedMapBuilderEntriesIterator<K, V>(map: PersistentO
     }
 }
 
-private data class MutableMapEntry<K, V>(private val mutableMap: MutableMap<K, Links<K, V>>,
-                                    override val key: K,
-                                    private var links: Links<K, V>) : MutableMap.MutableEntry<K, V> {
+private class MutableMapEntry<K, V>(private val mutableMap: MutableMap<K, Links<K, V>>,
+                                    key: K,
+                                    private var links: Links<K, V>) : MapEntry<K, V>(key, links.value), MutableMap.MutableEntry<K, V> {
     override val value: V
         get() = links.value
 
@@ -78,10 +80,6 @@ private data class MutableMapEntry<K, V>(private val mutableMap: MutableMap<K, L
         mutableMap[key] = links
         return result
     }
-
-    override fun toString(): String {
-        return key.toString() + "=" + value.toString()
-    }
 }
 
 internal class PersistentOrderedMapBuilderKeysIterator<out K, out V>(map: PersistentOrderedMapBuilder<K, V>): MutableIterator<K> {

kotlinx-collections-immutable/src/main/kotlin/kotlinx/collections/immutable/implementations/persistentOrderedMap/PersistentOrderedMapContentIterators.kt

@@ -16,6 +16,8 @@
 
 package kotlinx.collections.immutable.implementations.persistentOrderedMap
 
+import kotlinx.collections.immutable.implementations.immutableMap.MapEntry
+
 internal open class PersistentOrderedMapLinksIterator<K, out V>(internal var nextKey: K?,
                                                                 internal val map: Map<K, Links<K, V>>) : Iterator<Links<K, V>> {
     internal var index = 0
@@ -50,12 +52,6 @@ internal class PersistentOrderedMapEntriesIterator<out K, out V>(map: Persistent
     }
 }
 
-private data class MapEntry<out K, out V>(override val key: K, override val value: V) : Map.Entry<K, V> {
-    override fun toString(): String {
-        return key.toString() + "=" + value.toString()
-    }
-}
-
 internal class PersistentOrderedMapKeysIterator<out K, out V>(map: PersistentOrderedMap<K, V>): Iterator<K> {
     private val internal = PersistentOrderedMapLinksIterator(map.firstKey, map.map)