Implemented TLazy + Tests

Src/Myc.Core.Signals.pas

@@ -9,18 +9,12 @@ uses
 
 type
     TMycState = class abstract( TInterfacedObject, IMycState )
-    strict private
-    class var
-        FNull: IMycState;
-        class constructor ClassCreate;
     protected
         function GetIsSet: Boolean; virtual; abstract;
     public
         function Subscribe(Subscriber: IMycSubscriber): TMycSubscription; virtual; abstract;
         procedure Unsubscribe(Tag: TMycNotifyList<IMycSubscriber>.TTag); virtual; abstract;
         property IsSet: Boolean read GetIsSet;
-        // Provides access to the singleton null latch instance (always set).
-        class property Null: IMycState read FNull;
     end;
 
     // TMycNullState implements a "null object" pattern for IMycState.
@@ -42,9 +36,6 @@ type
     TMycLatch = class(TMycState, IMycLatch)
     strict private
         FSubscribers: TMycNotifyList<IMycSubscriber>; // List of subscribers waiting for this latch to be set.
-    class var
-        FNull: IMycLatch; // Singleton instance of a latch that is always set.
-        class constructor ClassCreate; // Class constructor to initialize FNull.
     private
         [volatile] FCount: Integer; // The internal countdown value for the latch.
         function GetState: IMycState; // Implementation for IMycLatch.GetState and IMycFlag.GetState.
@@ -56,9 +47,6 @@ type
         constructor Create(ACount: Integer);
         destructor Destroy; override;
 
-        // Factory method: creates a new countdown latch or returns the Null latch if Count <= 0.
-        class function CreateLatch(Count: Integer): IMycLatch; static;
-
         // IMycSignal implementation
         function Subscribe(Subscriber: IMycSubscriber): TMycSubscription; override;
         procedure Unsubscribe(Tag: TMycNotifyList<IMycSubscriber>.TTag); override;
@@ -67,9 +55,12 @@ type
         // Decrements the internal count. If the count reaches zero,
         // registered subscribers are notified, and the latch becomes permanently set.
         function Notify: Boolean;
+    end;
 
-        // Provides access to the singleton null latch instance (always set).
-        class property Null: IMycLatch read FNull;
+    TMycNullLatch = class( TInterfacedObject, IMycLatch )
+    private
+        function GetState: IMycState;
+        function Notify: Boolean;
     end;
 
     // TMycDirty implements a resettable "dirty flag".
@@ -91,7 +82,6 @@ type
         // Factory method to create a new TMycDirty instance.
         class function CreateDirty: IMycDirty; static;
 
-        // IMycSignal implementation
         function Subscribe(Subscriber: IMycSubscriber): TMycSubscription; override;
         procedure Unsubscribe(Tag: TMycNotifyList<IMycSubscriber>.TTag); override;
 
@@ -103,17 +93,18 @@ type
         function Reset: Boolean;
     end;
 
+    TMycNullDirty = class( TInterfacedObject, IMycDirty )
+    private
+        function GetState: IMycState;
+        function Notify: Boolean;
+        function Reset: Boolean;
+    end;
+
 implementation
 
 uses
     System.SyncObjs; // For TInterlocked
 
-class constructor TMycState.ClassCreate;
-begin
-    // Create a singleton null latch instance that is initially (and always) set.
-    FNull := TMycNullState.Create(); // Calls the instance constructor
-end;
-
 { TMycNullState }
 
 constructor TMycNullState.Create;
@@ -142,6 +133,18 @@ begin
     // Unsubscribing from a null state has no effect.
 end;
 
+{ TMycNullLatch }
+
+function TMycNullLatch.GetState: IMycState;
+begin
+    Result := TState.Null;
+end;
+
+function TMycNullLatch.Notify: Boolean;
+begin
+    Result := false;
+end;
+
 { TMycLatch }
 
 constructor TMycLatch.Create(ACount: Integer);
@@ -152,27 +155,12 @@ begin
     FSubscribers.Create;
 end;
 
-class constructor TMycLatch.ClassCreate;
-begin
-    // Create a singleton null latch instance that is initially (and always) set.
-    FNull := TMycLatch.Create(0); // Calls the instance constructor
-end;
-
 destructor TMycLatch.Destroy;
 begin
     FSubscribers.Destroy;
     inherited;
 end;
 
-class function TMycLatch.CreateLatch(Count: Integer): IMycLatch;
-begin
-    // Factory method: returns a new latch or the shared Null latch if Count <= 0.
-    if Count > 0 then
-        Result := TMycLatch.Create(Count) // Instance constructor
-    else
-        Result := FNull;
-end;
-
 function TMycLatch.Notify: Boolean;
 var
     currentCountAfterDecrement: Integer;
@@ -259,6 +247,23 @@ begin
     end;
 end;
 
+{ TMycNullDirty }
+
+function TMycNullDirty.GetState: IMycState;
+begin
+    Result := TState.Null;
+end;
+
+function TMycNullDirty.Notify: Boolean;
+begin
+    Result := false;
+end;
+
+function TMycNullDirty.Reset: Boolean;
+begin
+    Result := true;
+end;
+
 { TMycDirty }
 
 constructor TMycDirty.Create;