Forum: Ruby class << Foo; include Foo; end

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Thomas H. (Guest)
on 2007-04-09 03:10
(Received via mailing list)
Hello,

how should I group some stateless functions into a module and use them
in a very simple way without littering the namespace? E.g. if the
module is ``Foo'' with at least one function foo, then I'd like to use
that module in a way as simple like that:

  require 'Foo'
  puts Foo.foo("world")

The first solution that I've found is to write Foo.rb like follows:

  module Foo
    def foo(s)
      "Hello, #{s}\n"
    end
  end

  class << Foo
    include Foo
  end

Is that Ok? Or is there even a simpler way?

Regards
  Thomas
Gary W. (Guest)
on 2007-04-09 03:30
(Received via mailing list)
On Apr 8, 2007, at 7:10 PM, Thomas H. wrote:
>   end
That is fine.  There are several variations:

module Foo
   def foo(s)
     "Hello, #{s}\n"
   end
   extend self
end

Your example and my variation enable the module to
respond to *all* of its instance methods.

If you only want the module to respond to some of its instance
methods you'll want to look at the following variations:

module Foo
   def foo(s)
     "Hello, #{s}\n"
   end
   module_function :foo
end

or

module Foo;end
def Foo.foo(s)
   "Hello, #{s}\n"
end




Gary W.
Gavin K. (Guest)
on 2007-04-09 08:25
(Received via mailing list)
On Apr 8, 5:05 pm, Thomas H. <removed_email_address@domain.invalid> wrote:
> how should I group some stateless functions into a module and use them
> in a very simple way without littering the namespace? E.g. if the
> module is ``Foo'' with at least one function foo, then I'd like to use
> that module in a way as simple like that:
>
>   require 'Foo'
>   puts Foo.foo("world")

module Foo
  def self.foo( msg )
    puts "Hello #{msg}"
  end
end
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