Add object version of the method concat -> concatTo, reverse, slice and

join.

Author: javadev

src/main/java/com/github/underscore/$.java

@@ -559,14 +559,7 @@ public static <K, E> Map<K, Integer> countBy(final Iterable<E> iterable, Functio
     }
 
     public static <E> E[] toArray(final Iterable<E> iterable) {
-        final List<E> list = newArrayList();
-        each(iterable, new Block<E>() {
-            @Override
-            public void apply(E elem) {
-                list.add(elem);
-            }
-        });
-        return (E[]) list.toArray();
+        return (E[]) newArrayList(iterable).toArray();
     }
 
     public static int size(final Iterable<?> iterable) {
@@ -1754,6 +1747,10 @@ public static <T> String join(final T[] array, final String separator) {
         return join(Arrays.asList(array), separator);
     }
 
+    public String join(final String separator) {
+        return join(iterable, separator);
+    }
+
     public static <T> T[] concat(final T[] first, final T[] ... other) {
         int length = 0;
         for (T[] otherItem : other) {
@@ -1768,26 +1765,31 @@ public static <T> T[] concat(final T[] first, final T[] ... other) {
         return result;
     }
 
-    public static <T> List<T> concat(final List<T> first, final List<T> ... other) {
+    public static <T> List<T> concat(final Iterable<T> first, final Iterable<T> ... other) {
         int length = 0;
-        for (List<T> otherItem : other) {
-            length += otherItem.size();
+        for (Iterable<T> otherItem : other) {
+            length += size(otherItem);
         }
-        final T[] result = (T[]) Arrays.copyOf(first.toArray(), first.size() + length);
+        final T[] result = (T[]) Arrays.copyOf(toArray(first), size(first) + length);
         int index = 0;
-        for (List<T> otherItem : other) {
-            System.arraycopy(otherItem.toArray(), 0, result, first.size() + index, otherItem.size());
-            index += otherItem.size();
+        for (Iterable<T> otherItem : other) {
+            System.arraycopy(toArray(otherItem), 0, result, size(first) + index, size(otherItem));
+            index += size(otherItem);
         }
         return (List<T>) Arrays.asList(result);
     }
 
-    public static <T> List<T> slice(final List<T> list, final int start) {
+
+    public List<T> concatTo(final Iterable<T> ... other) {
+        return concat(iterable, other);
+    }
+
+    public static <T> List<T> slice(final Iterable<T> list, final int start) {
         final List<T> result;
         if (start > 0) {
-            result = list.subList(start, list.size());
+            result = newArrayList(list).subList(start, size(list));
         } else {
-            result = list.subList(list.size() + start, list.size());
+            result = newArrayList(list).subList(size(list) + start, size(list));
         }
         return result;
     }
@@ -1796,19 +1798,23 @@ public static <T> T[] slice(final T[] array, final int start) {
         return (T[]) slice(Arrays.asList(array), start).toArray();
     }
 
-    public static <T> List<T> slice(final List<T> list, final int start, final int end) {
+    public List<T> slice(final int start) {
+        return slice(iterable, start);
+    }
+
+    public static <T> List<T> slice(final Iterable<T> list, final int start, final int end) {
         final List<T> result;
         if (start > 0) {
             if (end > 0) {
-                result = list.subList(start, end);
+                result = newArrayList(list).subList(start, end);
             } else {
-                result = list.subList(start, list.size() + end);
+                result = newArrayList(list).subList(start, size(list) + end);
             }
         } else {
             if (end > 0) {
-                result = list.subList(list.size() + start, end);
+                result = newArrayList(list).subList(size(list) + start, end);
             } else {
-                result = list.subList(list.size() + start, list.size() + end);
+                result = newArrayList(list).subList(size(list) + start, size(list) + end);
             }
         }
         return result;
@@ -1818,7 +1824,11 @@ public static <T> T[] slice(final T[] array, final int start, final int end) {
         return (T[]) slice(Arrays.asList(array), start, end).toArray();
     }
 
-    public static <T> List<T> reverse(final List<T> list) {
+    public List<T> slice(final int start, final int end) {
+        return slice(iterable, start, end);
+    }
+
+    public static <T> List<T> reverse(final Iterable<T> list) {
         final List<T> result = (List<T>) clone(newArrayList(list));
         Collections.reverse(result);
         return result;
@@ -1828,6 +1838,10 @@ public static <T> T[] reverse(final T[] array) {
         return (T[]) reverse(newArrayList(Arrays.asList(array))).toArray();
     }
 
+    public List<T> reverse() {
+        return reverse(iterable);
+    }
+
     public Iterable<T> getIterable() {
         return iterable;
     }

src/test/java/com/github/underscore/FunctionsTest.java

@@ -143,7 +143,7 @@ public void once() throws Exception {
         Function<Void> onceIncr = $.once(incr);
         onceIncr.apply();
         onceIncr.apply();
-        Thread.sleep(32);
+        Thread.sleep(48);
         assertEquals("incr was called only once", 1, counter[0]);
     }
 

src/test/java/com/github/underscore/UnderscoreTest.java

@@ -68,6 +68,7 @@ public Integer apply(String arg) {
     @Test
     public void join() {
         assertEquals("some-words-example", $.join(asList("some", "words", "example"), "-"));
+        assertEquals("some-words-example", new $(asList("some", "words", "example")).join("-"));
         assertEquals("some-words-example", $.join(new String[] {"some", "words", "example"}, "-"));
         assertEquals("some-words-example", $.chain(asList("some", "words", "example")).join("-").item());
     }
@@ -85,9 +86,11 @@ public void compareStrings() {
     public void concat() {
         assertEquals(asList(1, 2, 3, 4), asList($.concat(new Integer[] {1, 2}, new Integer[] {3, 4})));
         assertEquals(asList(1, 2, 3, 4), $.concat(asList(1, 2), asList(3, 4)));
+        assertEquals(asList(1, 2, 3, 4), new $(asList(1, 2)).concatTo(asList(3, 4)));
         assertEquals("[1, 2, 3, 4]", $.chain(asList(1, 2)).concat(asList(3, 4)).value().toString());
         assertEquals(asList(1, 2, 3, 4), asList($.concat(new Integer[] {1, 2}, new Integer[] {3}, new Integer[] {4})));
         assertEquals(asList(1, 2, 3, 4), $.concat(asList(1, 2), asList(3), asList(4)));
+        assertEquals(asList(1, 2, 3, 4), new $(asList(1, 2)).concatTo(asList(3), asList(4)));
     }
 
 /*
@@ -101,9 +104,11 @@ public void concat() {
     @Test
     public void slice() {
         assertEquals(asList(3, 4, 5), $.slice(asList(1, 2, 3, 4, 5), 2));
+        assertEquals(asList(3, 4, 5), new $(asList(1, 2, 3, 4, 5)).slice(2));
         assertEquals(asList(2, 3, 4), $.slice(asList(1, 2, 3, 4, 5), 1, 4));
         assertEquals(asList(2, 3, 4), $.slice(asList(1, 2, 3, 4, 5), 1, -1));
         assertEquals(asList(3), $.slice(asList(1, 2, 3, 4, 5), 2, 3));
+        assertEquals(asList(3), new $(asList(1, 2, 3, 4, 5)).slice(2, 3));
         assertEquals(asList(4, 5), $.slice(asList(1, 2, 3, 4, 5), -2));
         assertEquals(asList(3, 4), $.slice(asList(1, 2, 3, 4, 5), -3, -1));
         assertEquals(asList(3, 4), $.slice(asList(1, 2, 3, 4, 5), -3, 4));
@@ -119,6 +124,7 @@ public void slice() {
     @Test
     public void reverse() {
         assertEquals("[3, 2, 1]", $.reverse(asList(1, 2, 3)).toString());
+        assertEquals("[3, 2, 1]", new $(asList(1, 2, 3)).reverse().toString());
         assertEquals("[3, 2, 1]", asList($.reverse(new Integer[] {1, 2, 3})).toString());
         assertEquals("[3, 2, 1]", $.chain(asList(1, 2, 3)).reverse().value().toString());
     }