More Stream API koans and doc update to make it clear how to run a particular file.

README.md

@@ -14,6 +14,7 @@ https://github.com/matyb/java-koans/archive/master.zip
     * *gradle*: wrapper for build library used to build koans source, setup project files in eclipse/idea, run tests, etc. you probably don't need to touch anything in here
 * Change directory to the koans directory: ```cd koans```
 * If you are using windows enter: ```run.bat``` or ```./run.sh``` if you are using Mac or Linux
+* (Optional) If, rather than starting from the beginning, you'd like to work on a particular topic, you can run the koans startup script like so: ```./run.sh java8.AboutStreams``` (where ```java8``` is the subdirectory, and ```AboutStreams``` is the class you'd like to work on)
 
 Developing a Koan:
 ==================

koans/src/java8/AboutStreams.java

@@ -92,6 +92,62 @@ public void parallelMapReduce() {
         assertEquals(lengthSum, __);
     }
 
+    @Koan
+    public void streamFromAnArray() {
+        int[] ints = {4, 5, 6};
+        long numberOfElements = Arrays.stream(ints).count();
+        assertEquals(numberOfElements, __);
+    }
+
+    @Koan
+    public void allMatch() {
+        boolean allNonEmpty = places.stream().allMatch(cityName -> !cityName.isEmpty());
+        assertEquals(allNonEmpty, __);
+    }
+
+    @Koan
+    public void anyMatch() {
+        boolean anyStartsWithX = places.stream().anyMatch(cityName -> cityName.startsWith("X"));
+        assertEquals(anyStartsWithX, __);
+    }
+
+    @Koan
+    public void streamOf() {
+        long count = Stream.of("foo", "bar").count();
+        assertEquals(count, __);
+    }
+
+    @Koan
+    public void distinct() {
+        long count = Stream.of("foo", "bar", "bar").distinct().count();
+        assertEquals(count, __);
+    }
+
+    @Koan
+    public void findFirst() {
+        String first = places.stream().findFirst().get();
+        assertEquals(first, __);
+    }
+
+    @Koan
+    public void flatMap() {
+        List<List<String>> listOfLists = Arrays.asList(Arrays.asList("foo", "bar"), Arrays.asList("one", "two"));
+        assertEquals(listOfLists.stream().findFirst().get(), __);
+        Stream streamOfStrings = listOfLists.stream().flatMap(list -> list.stream());
+        assertEquals(streamOfStrings.findFirst().get(), __);
+    }
+
+    List<String> listOfStrings = Arrays.asList("This is the first string.",
+            "This line follows the first line.");
+
+    @Koan
+    public void wordCountUsingFlatMap() {
+        long wordCount = listOfStrings.stream()
+                // use flatMap method here to count words in listOfStrings
+                .count();
+        assertEquals(wordCount, 11L);
+    }
+
     @Koan
     public void limitSkip() {
         int lengthSum_Limit_3_Skip_1 = places.stream()
@@ -102,6 +158,18 @@ public void limitSkip() {
         assertEquals(lengthSum_Limit_3_Skip_1, __);
     }
 
+    @Koan
+    public void sorted() {
+        String second = places.stream().sorted().skip(1).findFirst().get();
+        assertEquals(second, __);
+    }
+
+    @Koan
+    public void sortedReversed() {
+        String first = places.stream().sorted(Comparator.reverseOrder()).findFirst().get();
+        assertEquals(first, __);
+    }
+
     @Koan
     public void lazyEvaluation() {
         Stream stream = places.stream()