September 2017 Update

Task/Delegates/Elena/delegates-1.elena

@@ -0,0 +1,54 @@
+import extensions.
+import system'routines.
+
+class IOperable
+{
+    operate
+    [
+        NotSupportedException new; raise.
+    ]
+}
+
+class Operable :: IOperable
+{
+    operate
+        = "delegate implementation".
+}
+
+class Delegator
+{
+    object theDelegate.
+
+    constructor new
+    [
+        theDelegate := nil.
+    ]
+
+    set Delegate:obj
+    [
+        if ($nil == obj)
+            [ theDelegate := $nil. ];
+            [ theDelegate := obj. ].
+    ]
+
+    operate(Object operable)
+        = "default implementation".
+
+    operate(IOperable operable)
+        = operable operate.
+
+    operate
+        <= operate(theDelegate).
+}
+
+program =
+[
+    var delegator := Delegator new.
+
+    (nil, Object new, Operable new) forEach(:o)
+    [
+       delegator Delegate := o.
+
+       console printLine(delegator operate).
+    ].
+].

Task/Delegates/Elena/delegates-2.elena

@@ -0,0 +1,53 @@
+import extensions.
+import system'routines.
+
+class Operable
+{
+    operable = $self.
+
+    operate
+        = "delegate implementation".
+}
+
+class Delegator
+{
+    object theDelegate.
+
+    constructor new
+    [
+        theDelegate := nil.
+    ]
+
+    set Delegate:obj
+    [
+        if ($nil == obj)
+            [ theDelegate := $nil. ];
+            [ theDelegate := obj. ].
+    ]
+
+    operate
+    [
+        // if the object does not support "get&operable" message - returns nil
+        var anOperable := theDelegate operable \ back:$nil.
+
+        if ($nil == anOperable)
+        [
+            ^ "default implementation".
+        ];
+        [
+            ^ anOperable operate.
+        ].
+    ]
+}
+
+program =
+[
+    var delegator := Delegator new.
+
+    (nil, Object new, Operable new) forEach(:o)
+    [
+       delegator Delegate := o.
+
+       console printLine(delegator operate).
+    ].
+].

Task/Delegates/Elena/delegates.elena

@@ -1,48 +0,0 @@
-#import system.
-#import system'routines.
-
-#class Operable
-{
-    #method cast:verb &to:target
-        = target::verb eval &delegate:$self.
-
-    #method operate
-        = "delegate implementation".
-}
-
-#class Delegator
-{
-    #field theDelegate.
-
-    #constructor new
-    [
-        theDelegate := nil.
-    ]
-
-    #method set &Delegate:obj
-    [
-        ($nil == obj)
-            ? [ theDelegate := nil. ]
-            ! [ theDelegate := obj. ].
-    ]
-
-    #method operate
-        = theDelegate cast:%eval &to:
-            {
-                delegate : o = o operate.
-
-                ! : o = "default implementation".
-            }.
-}
-
-#symbol program =
-[
-    #var delegator := Delegator new.
-
-    ($nil, Object new, Operable new) run &each: o
-    [
-       delegator set &Delegate:o.
-
-       console writeLine:(delegator operate).
-    ].
-].