using @tenderlove's suggested implementation to speed things up

activesupport/lib/active_support/core_ext/array/access.rb

@@ -6,7 +6,7 @@ class Array
   #   %w( a b c d ).from(10) # => %w()
   #   %w().from(0)           # => %w()
   def from(position)
-    position > length ? [] : self[position..-1]
+    [position, length] || []
   end
 
   # Returns the beginning of the array up to +position+.