From f89a00fa217bf532390c36c260a75712a99c6315 Mon Sep 17 00:00:00 2001
From: Daniel Hoeggerl <d.hoeggerl@diamonddogs.cc>
Date: Fri, 16 Dec 2016 13:30:05 +0100
Subject: [PATCH 1/3] add Optional.stream()

---
 .../main/java/solid/optional/Optional.java    | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/streams/src/main/java/solid/optional/Optional.java b/streams/src/main/java/solid/optional/Optional.java
index 5184be6..8c06389 100644
--- a/streams/src/main/java/solid/optional/Optional.java
+++ b/streams/src/main/java/solid/optional/Optional.java
@@ -3,6 +3,7 @@
 import solid.functions.Action1;
 import solid.functions.Func0;
 import solid.functions.Func1;
+import solid.stream.Stream;
 
 /**
  * Optional is a wrapper around a value that can be empty (null).
@@ -84,6 +85,24 @@ public <R> Optional<R> map(Func1<T, R> func1) {
         return value == null ? Optional.<R>empty() : Optional.of(func1.call(value));
     }
 
+    /**
+     * If a value is present return a sequential {@link Stream} containing only
+     * that value, otherwise return an empty {@code Stream}.
+     *
+     * @return the optional value as a {@code Stream}
+     */
+    public Stream<T> stream() {
+        if (!isPresent()) {
+            return Stream.of();
+        } else {
+            if (value instanceof Iterable) {
+                return Stream.stream((Iterable<T>) value);
+            } else {
+                return Stream.of(value);
+            }
+        }
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

From 7593e900e35646a02f908aded4e16977cb29507d Mon Sep 17 00:00:00 2001
From: Daniel Hoeggerl <d.hoeggerl@diamonddogs.cc>
Date: Mon, 19 Dec 2016 11:46:56 +0100
Subject: [PATCH 2/3] update Optional#stream to only use Stream#of

---
 streams/src/main/java/solid/optional/Optional.java | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/streams/src/main/java/solid/optional/Optional.java b/streams/src/main/java/solid/optional/Optional.java
index 8c06389..1b099df 100644
--- a/streams/src/main/java/solid/optional/Optional.java
+++ b/streams/src/main/java/solid/optional/Optional.java
@@ -92,15 +92,7 @@ public <R> Optional<R> map(Func1<T, R> func1) {
      * @return the optional value as a {@code Stream}
      */
     public Stream<T> stream() {
-        if (!isPresent()) {
-            return Stream.of();
-        } else {
-            if (value instanceof Iterable) {
-                return Stream.stream((Iterable<T>) value);
-            } else {
-                return Stream.of(value);
-            }
-        }
+        return value == null ? Stream.<T>of() : Stream.of(value);
     }
 
     @Override

From 33c25f782a2a26a67438e16f5f93e2717974ab45 Mon Sep 17 00:00:00 2001
From: Daniel Hoeggerl <d.hoeggerl@diamonddogs.cc>
Date: Mon, 19 Dec 2016 11:47:13 +0100
Subject: [PATCH 3/3] add tests for Optional#stream

---
 .../java/solid/optional/OptionalTest.java     | 32 ++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/streams/src/test/java/solid/optional/OptionalTest.java b/streams/src/test/java/solid/optional/OptionalTest.java
index 8f14a0b..74df842 100644
--- a/streams/src/test/java/solid/optional/OptionalTest.java
+++ b/streams/src/test/java/solid/optional/OptionalTest.java
@@ -2,12 +2,17 @@
 
 import org.junit.Test;
 
+import java.util.Arrays;
+import java.util.List;
+
 import solid.functions.Action1;
 import solid.functions.Func0;
 import solid.functions.Func1;
+import solid.stream.Stream;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.eq;
@@ -15,6 +20,7 @@
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static test_utils.AssertIterableEquals.assertIterableEquals;
 
 public class OptionalTest {
 
@@ -31,7 +37,9 @@ public void testNull() throws Exception {
         assertEquals(1, o.or(1));
         assertEquals(1, o.or(new Func0<Object>() {
             @Override
-            public Object call() {return 1;}
+            public Object call() {
+                return 1;
+            }
         }));
         assertNull(o.orNull());
         assertNull(o.map(null).orNull());
@@ -77,4 +85,26 @@ public String call(Integer value) {
 
         assertEquals((Integer) 1, o.get());
     }
+
+    @Test
+    public void testStream() throws Exception {
+        Optional<List<Integer>> o = Optional.of(Arrays.asList(1, 2, 3, 4));
+        assertNotNull(o.stream());
+        assertTrue(o.stream().first().isPresent());
+
+        Stream<Integer> s = o.stream().flatMap(new Func1<List<Integer>, Iterable<Integer>>() {
+            @Override
+            public Iterable<Integer> call(List<Integer> value) {
+                return value;
+            }
+        });
+        assertEquals(Integer.valueOf(1), s.first().get());
+        assertEquals(Integer.valueOf(4), s.last().get());
+
+        assertEquals(Optional.empty().stream(), Stream.of());
+
+        assertIterableEquals(s, Arrays.asList(1, 2, 3, 4));
+
+        assertEquals(Optional.of("Test").stream().first().get(), "Test");
+    }
 }
\ No newline at end of file