Accessing functions in a module without 'include'

ruby-talk
1

Usually I work with modules like this:

# Defining a module in one file
  module M
    def f(x)
      ....
    end
  end

# Using the module in another file
  require 'M'
  include M
  f(45)

Sometimes I would find it more convenient to *not* inject
the module's namespace into the user's namespace, i.e. to
do it without the include statement. I thought it would
be easy to qualify the foreign function with the module
name:

# Using the module in another file
# (this does not work)
  require 'M'
  M::f(45) # Error: undefined method 'f'

Maybe I'm thinking to Perlish here. Can it be done what I want
to achieve, and how?

Ronald

···

--
Ronald Fischer <ronald.fischer@venyon.com>
Phone: +49-89-452133-162

2

# Defining a module in one file
   module M
     module_function # <<<<<<<<< HERE
     def f(x)
       ....
     end
   end

T.

···

On Jun 29, 5:25 am, "Ronald Fischer" <ronald.fisc...@venyon.com> wrote:

Usually I work with modules like this:

3

Ronald Fischer wrote:

Usually I work with modules like this:

# Defining a module in one file
  module M
    def f(x)
      ....
    end
  end

# Using the module in another file
  require 'M'
  include M
  f(45)

Sometimes I would find it more convenient to *not* inject
the module's namespace into the user's namespace, i.e. to
do it without the include statement. I thought it would be easy to qualify the foreign function with the module
name:

# Using the module in another file
# (this does not work)
  require 'M'
  M::f(45) # Error: undefined method 'f'

Maybe I'm thinking to Perlish here. Can it be done what I want
to achieve, and how?

Not sure if it's what you want, but if you define M as follows it works:

   module M
     def self.f(x)
       ....
     end
   end

cheers,
mick

4

> Sometimes I would find it more convenient to *not* inject
> the module's namespace into the user's namespace, i.e. to
> do it without the include statement. I thought it would
> be easy to qualify the foreign function with the module
> name:
>
> # Using the module in another file
> # (this does not work)
> require 'M'
> M::f(45) # Error: undefined method 'f'
>
> Maybe I'm thinking to Perlish here. Can it be done what I want
> to achieve, and how?

Not sure if it's what you want, but if you define M as
follows it works:

   module M
     def self.f(x)
       ....
     end
   end

Thank you, this works perfectly well!

Ronald

5

  # Defining a module in one file
   module M
     module_function # <<<<<<<<< HERE
     def f(x)
       ....
     end
   end

Thank you, this is indeed one solution to my problem (though in the
end, I'm going to stick with Michael Hollins' proposal).

Ronald

6

Don't mention it :slight_smile: BTW, Just to make sure you know, you can't use
Micheal's solution if you still want the option of including the
Module elsewhere. In effect using module_function is the same as:

    module M
      def self.f(x)
        ....
      end
      def f(x)
        ....
      end
      private :f
    end

Probably you've already figured that out, but just in case...

T.

···

On Jul 2, 5:34 am, "Ronald Fischer" <ronald.fisc...@venyon.com> wrote:

> # Defining a module in one file
> module M
> module_function # <<<<<<<<< HERE
> def f(x)
> ....
> end
> end

Thank you, this is indeed one solution to my problem (though in the
end, I'm going to stick with Michael Hollins' proposal).

7

BTW, Just to make sure you know, you can't use
Micheal's solution if you still want the option of including the
Module elsewhere. In effect using module_function is the same as:

    module M
      def self.f(x)
        ....
      end
      def f(x)
        ....
      end
      private :f
    end

I wasn't aware that the instance functions would then go private,
but in my case this would be no problem anyway.

Ronald