Modernize for Java 11

Use variable type inference where possible. Also simplify returns.

Signed-off-by: Robert Varga <robert.varga@pantheon.tech>

Author: rovarga

triemap/src/main/java/tech/pantheon/triemap/AbstractEntrySet.java

@@ -48,13 +48,13 @@ public final boolean contains(final Object o) {
             return false;
         }
 
-        final Entry<?, ?> e = (Entry<?, ?>) o;
-        final Object key = e.getKey();
+        final var e = (Entry<?, ?>) o;
+        final var key = e.getKey();
         if (key == null) {
             return false;
         }
 
-        final V v = map.get(key);
+        final var v = map.get(key);
         return v != null && v.equals(e.getValue());
     }
 

triemap/src/main/java/tech/pantheon/triemap/AbstractIterator.java

@@ -85,10 +85,10 @@ public final Entry<K, V> next() {
      * @param in INode to be read.
      */
     private void readin(final INode<K, V> in) {
-        final MainNode<K, V> m = in.gcasRead(map);
+        final var m = in.gcasRead(map);
         if (m instanceof CNode) {
             // Enter the next level
-            final CNode<K, V> cn = (CNode<K, V>) m;
+            final var cn = (CNode<K, V>) m;
             depth++;
             nodeStack[depth] = cn.array;
             positionStack[depth] = -1;
@@ -108,7 +108,7 @@ private void advance() {
             int npos = positionStack[depth] + 1;
             if (npos < nodeStack[depth].length) {
                 positionStack [depth] = npos;
-                BasicNode elem = nodeStack[depth][npos];
+                var elem = nodeStack[depth][npos];
                 if (elem instanceof SNode) {
                     current = (SNode<K, V>) elem;
                 } else if (elem instanceof INode) {

triemap/src/main/java/tech/pantheon/triemap/CNode.java

@@ -114,27 +114,27 @@ private static int elementSize(final BasicNode elem, final ImmutableTrieMap<?, ?
     }
 
     CNode<K, V> updatedAt(final int pos, final BasicNode nn, final Gen newGen) {
-        int len = array.length;
-        BasicNode[] narr = new BasicNode[len];
+        final int len = array.length;
+        final var narr = new BasicNode[len];
         System.arraycopy(array, 0, narr, 0, len);
         narr[pos] = nn;
         return new CNode<>(newGen, bitmap, narr);
     }
 
     CNode<K, V> removedAt(final int pos, final int flag, final Gen newGen) {
-        BasicNode[] arr = array;
-        int len = arr.length;
-        BasicNode[] narr = new BasicNode[len - 1];
+        final var arr = array;
+        final int len = arr.length;
+        final var narr = new BasicNode[len - 1];
         System.arraycopy(arr, 0, narr, 0, pos);
         System.arraycopy(arr, pos + 1, narr, pos, len - pos - 1);
         return new CNode<>(newGen, bitmap ^ flag, narr);
     }
 
     CNode<K, V> insertedAt(final int pos, final int flag, final BasicNode nn, final Gen newGen) {
-        int len = array.length;
-        BasicNode[] narr = new BasicNode[len + 1];
+        final int len = array.length;
+        final var narr = new BasicNode[len + 1];
         System.arraycopy(array, 0, narr, 0, pos);
-        narr [pos] = nn;
+        narr[pos] = nn;
         System.arraycopy(array, pos, narr, pos + 1, len - pos);
         return new CNode<>(newGen, bitmap | flag, narr);
     }
@@ -145,11 +145,11 @@ CNode<K, V> insertedAt(final int pos, final int flag, final BasicNode nn, final
      */
     CNode<K, V> renewed(final Gen ngen, final TrieMap<K, V> ct) {
         int idx = 0;
-        final BasicNode[] arr = array;
+        final var arr = array;
         final int len = arr.length;
-        final BasicNode[] narr = new BasicNode[len];
+        final var narr = new BasicNode[len];
         while (idx < len) {
-            final BasicNode elem = arr[idx];
+            final var elem = arr[idx];
             if (elem instanceof INode) {
                 narr[idx] = ((INode<?, ?>) elem).copyToGen(ngen, ct);
             } else if (elem != null) {
@@ -168,7 +168,6 @@ MainNode<K, V> toContracted(final int lev) {
             }
             return this;
         }
-
         return this;
     }
 
@@ -177,12 +176,13 @@ MainNode<K, V> toContracted(final int lev) {
     //   null-inodes removed (those existing when the op began)
     // - if there are only null-i-nodes below, returns null
     MainNode<K, V> toCompressed(final TrieMap<?, ?> ct, final int lev, final Gen newGen) {
-        int bmp = bitmap;
+        final int bmp = bitmap;
+        final var arr = array;
+        final var tmparray = new BasicNode[arr.length];
         int idx = 0;
-        BasicNode[] arr = array;
-        BasicNode[] tmparray = new BasicNode[arr.length];
+
         while (idx < arr.length) { // construct new bitmap
-            BasicNode sub = arr[idx];
+            var sub = arr[idx];
             if (sub instanceof INode) {
                 final INode<?, ?> in = (INode<?, ?>) sub;
                 final MainNode<?, ?> inodemain = VerifyException.throwIfNull(in.gcasRead(ct));
@@ -202,9 +202,6 @@ private static BasicNode resurrect(final INode<?, ?> inode, final MainNode<?, ?>
 
     @Override
     public String toString() {
-        // val elems = collectLocalElems
-        // "CNode(sz: %d; %s)".format(elems.size,
-        // elems.sorted.mkString(", "))
         return "CNode";
     }
 }

triemap/src/main/java/tech/pantheon/triemap/Constants.java

@@ -22,7 +22,7 @@
  */
 final class Constants {
     private Constants() {
-
+        // Hidden on purpose
     }
 
     /**

triemap/src/main/java/tech/pantheon/triemap/EntryUtil.java

@@ -24,7 +24,7 @@
  */
 final class EntryUtil {
     private EntryUtil() {
-
+        // Hidden on purpose
     }
 
     /**

triemap/src/main/java/tech/pantheon/triemap/Gen.java

@@ -16,5 +16,5 @@
 package tech.pantheon.triemap;
 
 final class Gen {
-
+    // Just an identity object
 }