lib/straightedge/extend/array.rb in straightedge-0.1.1 vs lib/straightedge/extend/array.rb in straightedge-0.1.2

@@ -1,10 +1,17 @@
 class Array
   include Straightedge::Aspects::Positional
   include Straightedge::Aspects::Figural
 
-  def sum
-    inject(&:+)
+  def second; self[1] end
+  def third;  self[2] end
+
+  def sum(&blk)
+    if block_given?
+      map(&blk).sum
+    else
+      inject(&:+)
+    end
   end
 
   def mean 
     sum / size
   end