From 117e22cdd0d6b20968fc39e2c8e1a7e6c73e9e73 Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Sat, 4 Jun 2016 16:13:59 +0100
Subject: Use single instance of None

---
 Mammoth/Couscous/java/util/HashMap.cs               | 2 +-
 Mammoth/Couscous/java/util/Optional.cs              | 7 ++++++-
 Mammoth/Couscous/mammoth/internal/util/Casts.cs     | 2 +-
 Mammoth/Couscous/mammoth/internal/util/Iterables.cs | 2 +-
 Mammoth/Couscous/mammoth/internal/util/Lists.cs     | 2 +-
 5 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/Mammoth/Couscous/java/util/HashMap.cs b/Mammoth/Couscous/java/util/HashMap.cs
index 38e516e..10070fc 100644
--- a/Mammoth/Couscous/java/util/HashMap.cs
+++ b/Mammoth/Couscous/java/util/HashMap.cs
@@ -30,7 +30,7 @@ namespace Mammoth.Couscous.java.util {
             if (_dictionary.ContainsKey(key)) {
                 return new Some<TValue>(_dictionary[key]);
             } else {
-                return new None<TValue>();
+                return None<TValue>.Instance;
             }
         }
         
diff --git a/Mammoth/Couscous/java/util/Optional.cs b/Mammoth/Couscous/java/util/Optional.cs
index f295688..b5be056 100644
--- a/Mammoth/Couscous/java/util/Optional.cs
+++ b/Mammoth/Couscous/java/util/Optional.cs
@@ -16,6 +16,11 @@ namespace Mammoth.Couscous.java.util
     }
 
 	internal class None<T> : Optional<T> {
+		internal static readonly None<T> Instance = new None<T>();
+		
+		private None() {
+		}
+		
 		public bool isPresent() {
 			return false;
 		}
@@ -92,7 +97,7 @@ namespace Mammoth.Couscous.java.util
     {
 		internal static Optional<T> empty<T>()
         {
-			return new None<T>();
+			return None<T>.Instance;
         }
         
         internal static Optional<T> of<T>(T value)
diff --git a/Mammoth/Couscous/mammoth/internal/util/Casts.cs b/Mammoth/Couscous/mammoth/internal/util/Casts.cs
index c342e20..29af07a 100644
--- a/Mammoth/Couscous/mammoth/internal/util/Casts.cs
+++ b/Mammoth/Couscous/mammoth/internal/util/Casts.cs
@@ -6,7 +6,7 @@ namespace Mammoth.Couscous.org.zwobble.mammoth.@internal.util {
             if (value is T) {
                 return new Some<T>((T) value);
             } else {
-                return new None<T>();
+                return None<T>.Instance;
             }
         }
     }
diff --git a/Mammoth/Couscous/mammoth/internal/util/Iterables.cs b/Mammoth/Couscous/mammoth/internal/util/Iterables.cs
index b1e1477..ac571bc 100644
--- a/Mammoth/Couscous/mammoth/internal/util/Iterables.cs
+++ b/Mammoth/Couscous/mammoth/internal/util/Iterables.cs
@@ -25,7 +25,7 @@ namespace Mammoth.Couscous.org.zwobble.mammoth.@internal.util
 					return new Some<T>(value);
 				}
 			}
-			return new None<T>();
+			return None<T>.Instance;
 		}
 		
 		internal static Iterable<T> lazyFilter<T>(Iterable<T> iterable, Predicate<T> predicate) {
diff --git a/Mammoth/Couscous/mammoth/internal/util/Lists.cs b/Mammoth/Couscous/mammoth/internal/util/Lists.cs
index b914a34..db18a21 100644
--- a/Mammoth/Couscous/mammoth/internal/util/Lists.cs
+++ b/Mammoth/Couscous/mammoth/internal/util/Lists.cs
@@ -50,7 +50,7 @@ namespace Mammoth.Couscous.org.zwobble.mammoth.@internal.util {
         
         internal static Optional<T> tryGetLast<T>(List<T> list) {
             if (list.isEmpty()) {
-                return new None<T>();
+                return None<T>.Instance;
             } else {
                 return new Some<T>(list.get(list.size() - 1));
             }
-- 
cgit v1.2.3