Refactoring around multi-valued attributes.

lib/clamp/attribute/declaration.rb

@@ -8,8 +8,12 @@ module Declaration
       def define_accessors_for(attribute, &block)
         define_reader_for(attribute)
         define_default_for(attribute)
-        define_writer_for(attribute, &block)
-        define_multi_writer_for(attribute) if attribute.multivalued?
+        if attribute.multivalued?
+          define_appender_for(attribute, &block)
+          define_multi_writer_for(attribute)
+        else
+          define_simple_writer_for(attribute, &block)
+        end
       end
 
       def define_reader_for(attribute)
@@ -24,20 +28,25 @@ def define_default_for(attribute)
         end
       end
 
-      def define_writer_for(attribute, &block)
+      def define_simple_writer_for(attribute, &block)
         define_method(attribute.write_method) do |value|
-          if block
-            value = instance_exec(value, &block)
-          end
-          attribute.of(self)._write(value)
+          value = instance_exec(value, &block) if block
+          attribute.of(self).set(value)
+        end
+      end
+
+      def define_appender_for(attribute, &block)
+        define_method(attribute.append_method) do |value|
+          value = instance_exec(value, &block) if block
+          attribute.of(self)._append(value)
         end
       end
 
       def define_multi_writer_for(attribute)
-        define_method(attribute.multi_write_method) do |values|
+        define_method(attribute.write_method) do |values|
           attribute.of(self).set([])
           Array(values).each do |value|
-            attribute.of(self).write(value)
+            attribute.of(self).take(value)
           end
         end
       end

lib/clamp/attribute/definition.rb

@@ -40,16 +40,12 @@ def default_method
       end
 
       def write_method
-        if multivalued?
-          "append_to_#{attribute_name}"
-        else
-          "#{attribute_name}="
-        end
+        "#{attribute_name}="
       end
 
-      def multi_write_method
+      def append_method
         if multivalued?
-          "#{attribute_name}="
+          "append_to_#{attribute_name}"
         end
       end
 

lib/clamp/attribute/instance.rb

@@ -39,22 +39,28 @@ def _read
         end
       end
 
-      # default implementation of write_method
-      def _write(value)
-        if attribute.multivalued?
-          current_values = get || []
-          set(current_values + [value])
-        else
-          set(value)
-        end
+      # default implementation of append_method
+      def _append(value)
+        current_values = get || []
+        set(current_values + [value])
+      end
+
+      # default implementation of write_method for multi-valued attributes
+      def _replace(values)
+        set([])
+        Array(values).each { |value| take(value) }
       end
 
       def read
         command.send(attribute.read_method)
       end
 
-      def write(value)
-        command.send(attribute.write_method, value)
+      def take(value)
+        if attribute.multivalued?
+          command.send(attribute.append_method, value)
+        else
+          command.send(attribute.write_method, value)
+        end
       end
 
       def default_from_environment
@@ -64,7 +70,7 @@ def default_from_environment
         # Set the parameter value if it's environment variable is present
         value = ENV[attribute.environment_variable]
         begin
-          write(value)
+          take(value)
         rescue ArgumentError => e
           command.send(:signal_usage_error, "$#{attribute.environment_variable}: #{e.message}")
         end

lib/clamp/option/parsing.rb

@@ -29,7 +29,7 @@ def parse_options
           value = option.extract_value(switch, remaining_arguments)
 
           begin
-            option.of(self).write(value)
+            option.of(self).take(value)
           rescue ArgumentError => e
             signal_usage_error "option '#{switch}': #{e.message}"
           end

lib/clamp/parameter/parsing.rb

@@ -10,7 +10,7 @@ def parse_parameters
         self.class.parameters.each do |parameter|
           begin
             parameter.consume(remaining_arguments).each do |value|
-              parameter.of(self).write(value)
+              parameter.of(self).take(value)
             end
           rescue ArgumentError => e
             signal_usage_error "parameter '#{parameter.name}': #{e.message}"

spec/clamp/option/definition_spec.rb

@@ -209,10 +209,10 @@
 
     end
 
-    describe "#write_method" do
+    describe "#append_method" do
 
       it "is derived from the attribute_name" do
-        option.write_method.should == "append_to_header_list"
+        option.append_method.should == "append_to_header_list"
       end
 
     end

spec/clamp/parameter/definition_spec.rb

@@ -113,10 +113,10 @@
 
     end
 
-    describe "#write_method" do
+    describe "#append_method" do
 
       it "is derived from the attribute_name" do
-        parameter.write_method.should == "append_to_file_list"
+        parameter.append_method.should == "append_to_file_list"
       end
 
     end