lib/range_builder.rb in range_builder-1.0.0 vs lib/range_builder.rb in range_builder-1.0.1

@@ -20,11 +20,11 @@
   end
 
   # arg: sorted enum. elements must implement succ
   def self.build_from_sorted enum
     ranges = []
-    first = enum.first
-    last = nil
+    return ranges if enum.empty?
+    first = last = enum.first
     enum.each_cons(2) do |a,b|
       last = b
       if a.succ != b
         ranges << Range.new(first,a)
         first = b