Data commit

Task/Delegates/Zkl/delegates-1.zkl

@@ -0,0 +1,11 @@
+class Thingable{ var thing; }
+
+class Delegator{
+   var delegate;
+   fcn operation{
+      if (delegate) delegate.thing;
+      else "default implementation"
+   }
+}
+
+class Delegate(Thingable){ thing = "delegate implementation" }

Task/Delegates/Zkl/delegates-2.zkl

@@ -0,0 +1,7 @@
+    // Without a delegate:
+a:= Delegator();
+a.operation().println(); //--> "default implementation"
+
+    // With a delegate:
+a.delegate = Delegate();
+a.operation().println(); //-->"delegate implementation"

Task/Delegates/Zkl/delegates-3.zkl

@@ -0,0 +1,6 @@
+class [static] Logger{ // Only one logging resource
+   var [mixin=File] dst; // File like semantics, eg Data, Pipe
+   dst = File.DevNull;
+   // initially, the logger does nothing
+   fcn log(msg){dst.writeln(vm.pasteArgs())}
+}

Task/Delegates/Zkl/delegates-4.zkl

@@ -0,0 +1,6 @@
+Logger.log("this is a test"); //-->nada
+Logger.dst=Console;
+Logger.log("this is a test 2"); //-->writes to Console
+
+class B(Logger){ log("Hello from ",self,"'s constructor"); }
+B(); //-->Hello from Class(B)'s constructor