Update Iterables.

Author: gk-brown

README.md

@@ -1137,39 +1137,39 @@ var number = cast("abc", Double.class); // null
 The `Iterables` class contains methods for processing a sequence of values:
 
 ```java
-public static <T, R> Iterable<R> mapAll(Iterable<T> iterable, Function<? super T, ? extends R> transform) { ... }
-public static <T> Iterable<T> filter(Iterable<T> iterable, Predicate<? super T> predicate) { ... }
 public static <T> T firstOf(Iterable<T> iterable) { ... }
+public static <T> Iterable<T> filter(Iterable<T> iterable, Predicate<? super T> predicate) { ... }
+public static <T, R> Iterable<R> mapAll(Iterable<T> iterable, Function<? super T, ? extends R> transform) { ... }
 
 public static <T> boolean exists(Iterable<T> iterable, Predicate<? super T> predicate) { ... }
 ```
 
 These are provided as a less complex alternative to similar methods defined by the `java.util.stream.Stream` class:
 
 ```java
-var values = listOf("a", "ab", "abc");
+var values = listOf(1, 2, 3);
 
-var result = listOf(mapAll(values, String::length)); // 1, 2, 3
+var result = firstOf(values); // 1
 ```
 
 ```java
-var values = Arrays.asList(DayOfWeek.values());
-
-var result = mapOf(mapAll(values, value -> entry(value, value.ordinal())));
+var values = listOf(1, 2, 3);
 
-var i = result.get(DayOfWeek.MONDAY); // 0
+var result = listOf(filter(values, value -> value < 3)); // 1, 2
 ```
 
 ```java
-var values = listOf(1, 2, 3);
+var values = listOf("a", "ab", "abc");
 
-var result = listOf(filter(values, value -> value < 3)); // 1, 2
+var result = listOf(mapAll(values, String::length)); // 1, 2, 3
 ```
 
 ```java
-var values = listOf(1, 2, 3);
+var values = Arrays.asList(DayOfWeek.values());
 
-var result = firstOf(values); // 1
+var result = mapOf(mapAll(values, value -> entry(value, value.ordinal())));
+
+var i = result.get(DayOfWeek.MONDAY); // 0
 ```
 
 ```java

kilo-client/src/main/java/org/httprpc/kilo/util/Iterables.java

@@ -23,26 +23,6 @@
  * Provides static utility methods for working with iterables.
  */
 public class Iterables {
-    private static class MapAllIterator<T, R> implements Iterator<R> {
-        Iterator<T> iterator;
-        Function<? super T, ? extends R> transform;
-
-        MapAllIterator(Iterator<T> iterator, Function<? super T, ? extends R> transform) {
-            this.iterator = iterator;
-            this.transform = transform;
-        }
-
-        @Override
-        public boolean hasNext() {
-            return iterator.hasNext();
-        }
-
-        @Override
-        public R next() {
-            return transform.apply(iterator.next());
-        }
-    }
-
     private static class FilterIterator<T> implements Iterator<T> {
         Iterator<T> iterator;
         Predicate<? super T> predicate;
@@ -88,33 +68,49 @@ public T next() {
         }
     }
 
+    private static class MapAllIterator<T, R> implements Iterator<R> {
+        Iterator<T> iterator;
+        Function<? super T, ? extends R> transform;
+
+        MapAllIterator(Iterator<T> iterator, Function<? super T, ? extends R> transform) {
+            this.iterator = iterator;
+            this.transform = transform;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return iterator.hasNext();
+        }
+
+        @Override
+        public R next() {
+            return transform.apply(iterator.next());
+        }
+    }
+
     private Iterables() {
     }
 
     /**
-     * Transforms iterable contents.
+     * Retrieves the first element from an iterable.
      *
      * @param <T>
      * The element type.
      *
-     * @param <R>
-     * The target type.
-     *
      * @param iterable
-     * The iterable to transform.
-     *
-     * @param transform
-     * The transform function.
+     * The iterable.
      *
      * @return
-     * The transformed iterable.
+     * The iterable's first element, or {@code null} if the iterable is empty.
      */
-    public static <T, R> Iterable<R> mapAll(Iterable<T> iterable, Function<? super T, ? extends R> transform) {
-        if (iterable == null || transform == null) {
+    public static <T> T firstOf(Iterable<T> iterable) {
+        if (iterable == null) {
             throw new IllegalArgumentException();
         }
 
-        return () -> new MapAllIterator<>(iterable.iterator(), transform);
+        var iterator = iterable.iterator();
+
+        return iterator.hasNext() ? iterator.next() : null;
     }
 
     /**
@@ -141,25 +137,29 @@ public static <T> Iterable<T> filter(Iterable<T> iterable, Predicate<? super T>
     }
 
     /**
-     * Retrieves the first element from an iterable.
+     * Transforms iterable contents.
      *
      * @param <T>
      * The element type.
      *
+     * @param <R>
+     * The target type.
+     *
      * @param iterable
-     * The iterable to search.
+     * The iterable to transform.
+     *
+     * @param transform
+     * The transform function.
      *
      * @return
-     * The iterable's first element, or {@code null} if the iterable is empty.
+     * The transformed iterable.
      */
-    public static <T> T firstOf(Iterable<T> iterable) {
-        if (iterable == null) {
+    public static <T, R> Iterable<R> mapAll(Iterable<T> iterable, Function<? super T, ? extends R> transform) {
+        if (iterable == null || transform == null) {
             throw new IllegalArgumentException();
         }
 
-        var iterator = iterable.iterator();
-
-        return iterator.hasNext() ? iterator.next() : null;
+        return () -> new MapAllIterator<>(iterable.iterator(), transform);
     }
 
     /**

kilo-client/src/test/java/org/httprpc/kilo/util/IterablesTest.java

@@ -26,27 +26,16 @@
 
 public class IterablesTest {
     @Test
-    public void testMapAllToList() {
-        var values = listOf("a", "ab", "abc");
-
-        var result = listOf(mapAll(values, String::length)); // 1, 2, 3
-
-        assertEquals(listOf(1, 2, 3), result);
-
-        assertEquals(result, values.stream().map(String::length).collect(Collectors.toList()));
-    }
-
-    @Test
-    public void testMapAllToMap() {
-        var values = Arrays.asList(DayOfWeek.values());
+    public void testFirstOf() {
+        var values = listOf(1, 2, 3);
 
-        var result = mapOf(mapAll(values, value -> entry(value, value.ordinal())));
+        var result = firstOf(values); // 1
 
-        var i = result.get(DayOfWeek.MONDAY); // 0
+        assertEquals(1, result);
 
-        assertEquals(0, i);
+        assertEquals(result, values.stream().findFirst().orElse(null));
 
-        assertEquals(result, values.stream().collect(Collectors.toMap(value -> value, Enum::ordinal)));
+        assertNull(firstOf(listOf()));
     }
 
     @Test
@@ -66,16 +55,27 @@ public void testFilter() {
     }
 
     @Test
-    public void testFirstOf() {
-        var values = listOf(1, 2, 3);
+    public void testMapAllToList() {
+        var values = listOf("a", "ab", "abc");
 
-        var result = firstOf(values); // 1
+        var result = listOf(mapAll(values, String::length)); // 1, 2, 3
 
-        assertEquals(1, result);
+        assertEquals(listOf(1, 2, 3), result);
 
-        assertEquals(result, values.stream().findFirst().orElse(null));
+        assertEquals(result, values.stream().map(String::length).collect(Collectors.toList()));
+    }
 
-        assertNull(firstOf(listOf()));
+    @Test
+    public void testMapAllToMap() {
+        var values = Arrays.asList(DayOfWeek.values());
+
+        var result = mapOf(mapAll(values, value -> entry(value, value.ordinal())));
+
+        var i = result.get(DayOfWeek.MONDAY); // 0
+
+        assertEquals(0, i);
+
+        assertEquals(result, values.stream().collect(Collectors.toMap(value -> value, Enum::ordinal)));
     }
 
     @Test