in access.rb, documented edge cases of #from and #to and revised conventions

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

@@ -8,6 +8,7 @@ module ActiveSupport #:nodoc:
         #   %w( a b c d ).from(0)  # => %w( a b c d )
         #   %w( a b c d ).from(2)  # => %w( c d )
         #   %w( a b c d ).from(10) # => nil
+        #   %w().from(0)           # => nil
         def from(position)
           self[position..-1]
         end
@@ -17,51 +18,52 @@ module ActiveSupport #:nodoc:
         #   %w( a b c d ).to(0)  # => %w( a )
         #   %w( a b c d ).to(2)  # => %w( a b c )
         #   %w( a b c d ).to(10) # => %w( a b c d )
+        #   %w().to(0)           # => %w()
         def to(position)
           self[0..position]
         end
 
-        # Equal to self[1]
+        # Equals to <tt>self[1]</tt>.
         def second
           self[1]
         end
 
-        # Equal to self[2]
+        # Equals to <tt>self[2]</tt>.
         def third
           self[2]
         end
 
-        # Equal to self[3]
+        # Equals to <tt>self[3]</tt>.
         def fourth
           self[3]
         end
 
-        # Equal to self[4]
+        # Equals to <tt>self[4]</tt>.
         def fifth
           self[4]
         end
 
-        # Equal to self[5]
+        # Equals to <tt>self[5]</tt>.
         def sixth
           self[5]
         end
 
-        # Equal to self[6]
+        # Equals to <tt>self[6]</tt>.
         def seventh
           self[6]
         end
 
-        # Equal to self[7]
+        # Equals to <tt>self[7]</tt>.
         def eighth
           self[7]
         end
 
-        # Equal to self[8]
+        # Equals to <tt>self[8]</tt>.
         def ninth
           self[8]
         end
 
-        # Equal to self[9]
+        # Equals to <tt>self[9]</tt>.
         def tenth
           self[9]
         end