latest ruby design patterns stuff

Folders.rb

@@ -0,0 +1,47 @@
+class NamedSizedItem
+    @name = nil
+    @size = 0
+    def initialize(name)
+        @name = name
+    end
+    def name()
+        return @name
+    end
+    def size()
+        return @size
+    end
+end
+
+class NamedFile < NamedSizedItem
+    def initialize(name)
+        @name = name
+        @size = 1
+    end
+end
+
+class NamedFolder < NamedSizedItem
+    @files = []
+    def initialize(name)
+        @name = name
+        @files = []
+    end
+    def addFile(file)
+        @files << file
+    end
+    def size()
+        return @files.inject(0) { |res,elm| res + elm.size() }
+    end
+end
+
+file1 = NamedFile.new("readme")
+file2 = NamedFile.new("license")
+file3 = NamedFile.new("a.out")
+subFolder1 = NamedFolder.new("Sub1");
+subFolder2 = NamedFolder.new("Sub2");
+subFolder3 = NamedFolder.new("Sub3");
+subFolder1.addFile(file1)
+subFolder2.addFile(file2)
+subFolder3.addFile(file3)
+subFolder2.addFile(subFolder1)
+subFolder3.addFile(subFolder2)
+puts(subFolder3.size())

IncSingleton.rb

@@ -0,0 +1,8 @@
+require 'singleton' 
+# http://dalibornasevic.com/posts/9-ruby-singleton-pattern-again
+
+class IncSingleton
+   include Singleton
+end
+
+

MySingleton.rb

@@ -0,0 +1,17 @@
+# http://apidock.com/ruby/Module/private_class_method
+# http://dalibornasevic.com/posts/9-ruby-singleton-pattern-again
+class MySingleton
+   # attempt to limit access to the constructor
+   private_class_method :new
+   # class variable instance
+   @@instance = nil
+   def self.instance()
+      if (@@instance.nil?())
+          # self. and MySingleton tend not to work
+          @@instance = self.new()
+      end
+      return @@instance
+   end
+end
+
+