Find rubygems in ruby include stack

ike:~>>% ruby -e 'puts $".grep(/rubygems/)'
/Users/js/.rvm/rubies/ruby-1.9.1-p378/lib/ruby/1.9.1/rubygems.rb

mapping.rb

module ActionDispatch
  module Routing
    class Mapper
      ...
      module Resources
        ...
        private
          ...
          def save_scope
            {
              :path => @scope[:path],
              :name_prefix => @scope[:name_prefix]
            }
          end

          def restore_scope(hsh)
            @scope[:path] = hsh[:path]
            @scope[:name_prefix] = hsh[:name_prefix]
          end

          def with_shallow_scope(curr_scope)
            if !block_given?
              raise 'with_shallow_scope expects a block'
            end
            _saved_scope = save_scope
            shallow_scope(curr_scope)
            yield
            restore_scope(_saved_scope)
          end

          def shallow_scope(ref_scope)
            return if ref_scope.nil?
            return unless @scope.has_key? :shallow
            root_scope = @scope[:shallow]
            return if root_scope[:path] == ref_scope[:path]
            pathstart = namestart = 0
            unless @scope[:path].start_with? ref_scope[:path]
              raise 'shallow_scope path mismatch'
            end
            pathstop, namestop = ref_scope[:path].length-1, ref_scope[:name_prefix].length-1
            if @scope[:path].start_with? root_scope[:path]
              pathstart, namestart = root_scope[:path].length, root_scope[:name_prefix].length
            end
            @scope[:path] = @scope[:path].dup
            @scope[:path][pathstart..pathstop] = ''
            @scope[:name_prefix] = @scope[:name_prefix].dup
            @scope[:name_prefix][namestart..namestop] = ''
          end
      end
      ...
    end
  end
end