Removed Enumerable patches

* Not sure what I was thinking when I added these methods.  Patching
  Enumerable was a mistake for more than just this specific ticket.

[#1195 state:resolved]

dm-core.gemspec

@@ -9,7 +9,7 @@ Gem::Specification.new do |s|
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
   s.authors = ["Dan Kubb"]
-  s.date = %q{2010-02-04}
+  s.date = %q{2010-02-07}
   s.description = %q{Faster, Better, Simpler.}
   s.email = %q{dan.kubb@gmail.com}
   s.extra_rdoc_files = [
@@ -43,7 +43,6 @@ Gem::Specification.new do |s|
      "lib/dm-core/associations/one_to_one.rb",
      "lib/dm-core/associations/relationship.rb",
      "lib/dm-core/collection.rb",
-     "lib/dm-core/core_ext/enumerable.rb",
      "lib/dm-core/core_ext/kernel.rb",
      "lib/dm-core/core_ext/symbol.rb",
      "lib/dm-core/identity_map.rb",

lib/dm-core.rb

@@ -65,7 +65,6 @@
 require dir / 'transaction'                     # TODO: move to dm-more
 require dir / 'version'
 
-require dir / 'core_ext' / 'enumerable'
 require dir / 'core_ext' / 'kernel'             # TODO: do not load automatically
 require dir / 'core_ext' / 'symbol'             # TODO: do not load automatically
 

lib/dm-core/adapters/data_objects_adapter.rb

@@ -685,7 +685,7 @@ def comparison_statement(comparison, qualify)
             else
               return conditions_statement(comparison.foreign_key_mapping, qualify)
             end
-          elsif comparison.slug == :in && value.empty?
+          elsif comparison.slug == :in && !value.any?
             return []  # match everything
           end
 

lib/dm-core/query/conditions/comparison.rb

@@ -626,7 +626,7 @@ def valid_collection?(collection)
 
         # @api private
         def valid_range?(range)
-          (!range.empty? || negated?) && valid_for_subject?(range.first) && valid_for_subject?(range.last)
+          (range.any? || negated?) && valid_for_subject?(range.first) && valid_for_subject?(range.last)
         end
 
         # @api private

lib/dm-core/query/conditions/operation.rb

@@ -132,6 +132,17 @@ def slug
           self.class.slug
         end
 
+        # Get the first operand
+        #
+        # @return [AbstractOperation, AbstractComparison, Array]
+        #   returns the first operand
+        #
+        # @api semipublic
+        def first
+          each { |operand| return operand }
+          nil
+        end
+
         # Iterate through each operand in the operation
         #
         # @yield [operand]
@@ -149,6 +160,26 @@ def each
           self
         end
 
+        # Test to see if there are operands
+        #
+        # @return [Boolean]
+        #   returns true if there are operands
+        #
+        # @api semipublic
+        def empty?
+          @operands.empty?
+        end
+
+        # Test to see if there is one operand
+        #
+        # @return [Boolean]
+        #   true if there is only one operand
+        #
+        # @api semipublic
+        def one?
+          @operands.size == 1
+        end
+
         # Test if the operation is valid
         #
         # @return [Boolean]