Minor cleanup in aggregator framework (AggFinish now has proper order…

… of generics), added domain methods to TupleBrige, added a merge variant method to ObjectUtils.
SmartDataAnalytics · Jul 31, 2024 · 50def81 · 50def81
1 parent 939082f
commit 50def81
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Showing 7 changed files with 91 additions and 36 deletions.
diff --git a/aksw-commons-collectors/src/main/java/org/aksw/commons/collector/core/AggFinish.java b/aksw-commons-collectors/src/main/java/org/aksw/commons/collector/core/AggFinish.java
@@ -1,6 +1,7 @@
 package org.aksw.commons.collector.core;
 
 import java.io.Serializable;
+import java.util.Objects;
 import java.util.function.Function;
 
 import org.aksw.commons.collector.domain.Accumulator;
@@ -14,6 +15,8 @@
 public class AggFinish<B, I, E, O, C extends Aggregator<B, E, I>>
     implements Aggregator<B, E, O>, Serializable
 {
+    private static final long serialVersionUID = 1L;
+
     private C subAgg;
     private Function<? super I, O> transform;
 
@@ -26,10 +29,18 @@ public AggFinish(C subAgg, Function<? super I, O> transform) {
     @Override
     public Accumulator<B, E, O> createAccumulator() {
         Accumulator<B, E, I> baseAcc = subAgg.createAccumulator();
-        Accumulator<B, E, O> result = new AccFinish(baseAcc);
+        Accumulator<B, E, O> result = new AccFinish<>(baseAcc, transform);
         return result;
     }
 
+    public C getSubAgg() {
+        return subAgg;
+    }
+
+    public Function<? super I, O> getTransform() {
+        return transform;
+    }
+
     public static <B, I, E, O, C extends Aggregator<B, E, I>> AggFinish<B, I, E, O, C> create(C subAgg, Function<? super I, O> transform) {
         AggFinish<B, I, E, O, C> result = new AggFinish<>(subAgg, transform);
         return result;
@@ -73,36 +84,43 @@ public boolean equals(Object obj) {
     }
 
 
-    public class AccFinish
-        implements Accumulator<B, E, O>, Serializable
+    public static class AccFinish<I, E, O, V>
+        implements Accumulator<I, E, V>, Serializable
     {
         private static final long serialVersionUID = 1L;
 
-        protected Accumulator<B, E, I> subAcc;
+        protected Accumulator<I, E, O> subAcc;
+        protected Function<? super O, V> transform;
 
-        public AccFinish(Accumulator<B, E, I> subAcc) {
+        public AccFinish(Accumulator<I, E, O> subAcc, Function<? super O, V> transform) {
             this.subAcc = subAcc;
+            this.transform = transform;
         }
 
         @Override
-        public void accumulate(B binding, E env) {
-            subAcc.accumulate(binding, env);
+        public void accumulate(I input, E env) {
+            subAcc.accumulate(input, env);
+        }
+
+        public Accumulator<I, E, O> getSubAcc() {
+            return subAcc;
         }
 
         @Override
-        public O getValue() {
-            I input = subAcc.getValue();
-            O result = transform.apply(input);
+        public V getValue() {
+            O accValue = subAcc.getValue();
+            V result = transform.apply(accValue);
             return result;
         }
 
+        /** Shortcut for {@code getEnclosingInstance().getTransform()} */
+        public Function<? super O, V> getTransform() {
+            return transform;
+        }
+
         @Override
         public int hashCode() {
-            final int prime = 31;
-            int result = 1;
-            result = prime * result + getEnclosingInstance().hashCode();
-            result = prime * result + ((subAcc == null) ? 0 : subAcc.hashCode());
-            return result;
+            return Objects.hash(subAcc, transform);
         }
 
         @Override
@@ -114,18 +132,7 @@ public boolean equals(Object obj) {
             if (getClass() != obj.getClass())
                 return false;
             AccFinish other = (AccFinish) obj;
-            if (!getEnclosingInstance().equals(other.getEnclosingInstance()))
-                return false;
-            if (subAcc == null) {
-                if (other.subAcc != null)
-                    return false;
-            } else if (!subAcc.equals(other.subAcc))
-                return false;
-            return true;
-        }
-
-        private AggFinish getEnclosingInstance() {
-            return AggFinish.this;
+            return Objects.equals(subAcc, other.subAcc) && Objects.equals(transform, other.transform);
         }
 
 //	    public static <B, I, O> Accumulator<B, O> create(Accumulator<B, I> subAcc, Function<? super I, O> transform) {
@@ -134,4 +141,4 @@ private AggFinish getEnclosingInstance() {
 //	    }
     }
 
-}
+}
diff --git a/aksw-commons-collectors/src/main/java/org/aksw/commons/collector/domain/Aggregator.java b/aksw-commons-collectors/src/main/java/org/aksw/commons/collector/domain/Aggregator.java
@@ -8,12 +8,11 @@
 import org.aksw.commons.lambda.serializable.SerializableFunction;
 
 /**
+* Interface for agregators.
 *
-* @author raven
-*
-*
-* @param <B> The type of bindings being accumulated by the accumulator
-* @param <T> The result object of the accumulation
+* @param <B> The type of bindings being accumulated by the accumulator.
+* @param <E> The environment/context to be passed to accumulator.
+* @param <T> The result object of the accumulation.
 */
 @FunctionalInterface
 public interface Aggregator<B, E, T> {
@@ -50,4 +49,4 @@ default Optional<T> accumulateAll(Iterator<? extends B> it, E env) {
        return Optional.ofNullable(acc.getValue());
    }
 
-}
+}
diff --git a/aksw-commons-paths/src/main/java/org/aksw/commons/path/core/Path.java b/aksw-commons-paths/src/main/java/org/aksw/commons/path/core/Path.java
@@ -29,6 +29,10 @@ public interface Path<T>
 
     Path<T> subpath(int beginIndex, int endIndex);
 
+//    default Path<T> subpath(int beginIndex) {
+//        return subpath(beginIndex, getNameCount());
+//    }
+
     boolean startsWith(Path<T> other);
     boolean endsWith(Path<T> other);
 
@@ -53,6 +57,9 @@ default T toSegment() {
         return result;
     }
 
-    /** May return e.g. the file system underlying a path. Return null if not applicable. */
+    /**
+     * Returns an object such as the file system underlying this path. Returns null if not applicable.
+     * Experimental.
+     */
     Object getSystem();
 }
diff --git a/aksw-commons-tuples/src/main/java/org/aksw/commons/tuple/bridge/TupleBridge.java b/aksw-commons-tuples/src/main/java/org/aksw/commons/tuple/bridge/TupleBridge.java
@@ -47,7 +47,7 @@ default void validateBuildArg(TupleBridge<?, ?> bridge) {
         int r = getDimension();
 
         if (cl != r) {
-            throw new IllegalArgumentException("components.length must equal rank but " + cl + " != " + r);
+            throw new IllegalArgumentException("components.length must equal dimension but " + cl + " != " + r);
         }
     }
 

diff --git a/aksw-commons-tuples/src/main/java/org/aksw/commons/tuple/bridge/TupleBridge3.java b/aksw-commons-tuples/src/main/java/org/aksw/commons/tuple/bridge/TupleBridge3.java
@@ -12,6 +12,18 @@ default int getDimension() {
         return 3;
     }
 
+    default C getArg0(D obj) {
+        return get(obj, 0);
+    }
+
+    default C getArg1(D obj) {
+        return get(obj, 1);
+    }
+
+    default C getArg2(D obj) {
+        return get(obj, 2);
+    }
+
     @Override
     default <T> D build(T obj, TupleAccessor<? super T, ? extends C> accessor) {
         C s = accessor.get(obj, 0);

diff --git a/aksw-commons-tuples/src/main/java/org/aksw/commons/tuple/bridge/TupleBridge4.java b/aksw-commons-tuples/src/main/java/org/aksw/commons/tuple/bridge/TupleBridge4.java
@@ -12,6 +12,22 @@ default int getDimension() {
         return 4;
     }
 
+    default C getArg0(D obj) {
+        return get(obj, 0);
+    }
+
+    default C getArg1(D obj) {
+        return get(obj, 1);
+    }
+
+    default C getArg2(D obj) {
+        return get(obj, 2);
+    }
+
+    default C getArg3(D obj) {
+        return get(obj, 3);
+    }
+
     @Override
     default <T> D build(T obj, TupleAccessor<? super T, ? extends C> accessor) {
         C g = accessor.get(obj, 0);

diff --git a/...-utils-parent/aksw-commons-utils/src/main/java/org/aksw/commons/util/obj/ObjectUtils.java b/...-utils-parent/aksw-commons-utils/src/main/java/org/aksw/commons/util/obj/ObjectUtils.java
@@ -69,6 +69,20 @@ public static <T> T mergeNonNull(T a, T b, BinaryOperator<T> merger) {
         return result;
     }
 
+    /** Similar to {@link #mergeNonNull(Object, Object, BinaryOperator)}
+     *  but with an additional supplier if both arguments are null. */
+    public static <T> T mergeNonNull(T a, T b, BinaryOperator<T> combiner, Supplier<T> nullCase) {
+        T result = a == null
+            ? b == null
+                ? nullCase.get()
+                : b
+            : b == null
+                ? a
+                : combiner.apply(a, b);
+        return result;
+    }
+
+
     /**
      * Supplier-based coalesce function as described in
      * https://benjiweber.co.uk/blog/2013/12/08/null-coalescing-in-java-8/