Fixing ArrayExample.iterator and BinaryFeaturesExample.iterator so th…

…ey throw NoSuchElementException rather than ArrayIndexOutOfBoundsException when exhausted. (#138)
oracle · Apr 27, 2021 · 42ff2a0 · 42ff2a0
1 parent 0cbf236
commit 42ff2a0
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diff --git a/Core/src/main/java/org/tribuo/impl/ArrayExample.java b/Core/src/main/java/org/tribuo/impl/ArrayExample.java
@@ -34,6 +34,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 import java.util.Objects;
 import java.util.PriorityQueue;
 import java.util.Set;
@@ -570,6 +571,9 @@ public boolean hasNext() {
 
         @Override
         public Feature next() {
+            if (!hasNext()) {
+                throw new NoSuchElementException("Iterator exhausted at position " + pos);
+            }
             Feature f = new Feature(featureNames[pos],featureValues[pos]);
             pos++;
             return f;

diff --git a/Core/src/main/java/org/tribuo/impl/BinaryFeaturesExample.java b/Core/src/main/java/org/tribuo/impl/BinaryFeaturesExample.java
@@ -25,6 +25,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 import java.util.Objects;
 import java.util.PriorityQueue;
 import java.util.Set;
@@ -502,6 +503,9 @@ public boolean hasNext() {
 
         @Override
         public Feature next() {
+            if (!hasNext()) {
+                throw new NoSuchElementException("Iterator exhausted at position " + pos);
+            }
             Feature f = new Feature(featureNames[pos], 1.0);
             pos++;
             return f;

diff --git a/Core/src/test/java/org/tribuo/ExampleTest.java b/Core/src/test/java/org/tribuo/ExampleTest.java
@@ -30,6 +30,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
@@ -261,6 +262,57 @@ public void invalidListExampleTest() {
         // This example should be valid
         assertTrue(test.validateExample());
     }
+
+    @Test
+    public void exampleIterators() {
+        MockOutput output = new MockOutput("UNK");
+        List<Feature> features = new ArrayList<>();
+        features.add(new Feature("A",1.0));
+        features.add(new Feature("C",1.0));
+        features.add(new Feature("B",1.0));
+
+        ArrayExample<MockOutput> array = new ArrayExample<>(output,features);
+        assertEquals(3,array.size());
+
+        Iterator<Feature> arrayItr = array.iterator();
+        assertTrue(arrayItr.hasNext());
+        assertEquals(features.get(0),arrayItr.next());
+        assertTrue(arrayItr.hasNext());
+        // Features are lexicographically sorted inside examples
+        assertEquals(features.get(2),arrayItr.next());
+        assertTrue(arrayItr.hasNext());
+        assertEquals(features.get(1),arrayItr.next());
+        assertFalse(arrayItr.hasNext());
+        assertThrows(NoSuchElementException.class, arrayItr::next);
+
+        ListExample<MockOutput> list = new ListExample<>(output,features);
+        assertEquals(3,list.size());
+
+        Iterator<Feature> listItr = list.iterator();
+        assertTrue(listItr.hasNext());
+        assertEquals(features.get(0),listItr.next());
+        assertTrue(listItr.hasNext());
+        // Features are lexicographically sorted inside examples
+        assertEquals(features.get(2),listItr.next());
+        assertTrue(listItr.hasNext());
+        assertEquals(features.get(1),listItr.next());
+        assertFalse(listItr.hasNext());
+        assertThrows(NoSuchElementException.class, listItr::next);
+
+        BinaryFeaturesExample<MockOutput> binary = new BinaryFeaturesExample<>(output,features);
+        assertEquals(3,binary.size());
+
+        Iterator<Feature> binaryItr = binary.iterator();
+        assertTrue(binaryItr.hasNext());
+        assertEquals(features.get(0),binaryItr.next());
+        assertTrue(binaryItr.hasNext());
+        // Features are lexicographically sorted inside examples
+        assertEquals(features.get(2),binaryItr.next());
+        assertTrue(binaryItr.hasNext());
+        assertEquals(features.get(1),binaryItr.next());
+        assertFalse(binaryItr.hasNext());
+        assertThrows(NoSuchElementException.class, binaryItr::next);
+    }
 
     @Test
     public void testBinaryFeaturesExample() {