Passage format added

lib/differ.rb

@@ -3,6 +3,7 @@
 require 'differ/format/ascii'
 require 'differ/format/color'
 require 'differ/format/html'
+require 'differ/format/passage'
 
 module Differ
   class << self
@@ -40,15 +41,16 @@ def format=(f)
     end
 
     def format
-      return @format || Format::Ascii
+      return @format || Format::Passage
     end
 
     def format_for(f)
       case f
-      when Module then f
-      when :ascii then Format::Ascii
-      when :color then Format::Color
-      when :html  then Format::HTML
+      when Module     then f
+      when :ascii     then Format::Ascii
+      when :color     then Format::Color
+      when :html      then Format::HTML
+      when :passage   then Format::Passage
       when nil    then nil
       else raise "Unknown format type #{f.inspect}"
       end
@@ -80,4 +82,4 @@ def change(method, array, index)
       @diff.same(array.shift)
     end
   end
-end
+end

lib/differ/format/passage.rb

@@ -0,0 +1,28 @@
+module Differ
+  module Format
+    module Passage
+      class << self
+        def format(change)
+          binding.pry
+          (change.change? && as_change(change)) ||
+          (change.delete? && as_delete(change)) ||
+          (change.insert? && as_insert(change)) ||
+          ''
+        end
+
+      private
+        def as_insert(change)
+          "{+#{change.insert.inspect}}"
+        end
+
+        def as_delete(change)
+          "{-#{change.delete.inspect}}"
+        end
+
+        def as_change(change)
+          "{#{change.delete.inspect} >> #{change.insert.inspect}}"
+        end
+      end
+    end
+  end
+end