Is there an acceptable way of putting multiple module declarations on the same line?

Question

I am working on a code base that has many modules nested 4 or 5 deep. Right now, this results in our code being heavily indented from the beginning.

Is there an acceptable way of putting multiple module declarations on the same line?

For example,

module A
  module B
    #do stuff
  end
end

Is there a way to make it something like this?

module A::B
  #do stuff
end

Though the previous block doesn't work, I was able to get this next one to work, however I am not sure if this is considered acceptable code construction.

module A module B
  #do stuff
end end

Answer 1

I think you've answered it yourself - your third segment looks pretty bad to my eye.

But, more to the point, if you did write module A::B and module A had never been defined before, you would be implicitly defining an (empty) module A, which doesn't seem very useful. And, once you've defined module A once, you're welcome to write module A::B to define module B. So it seems actively good to me that you can't use your second example.

Answer 2

You can use ; instead of \n safely in Ruby source files. Newlines before end are not important.

module A ; module B
    #do stuff
end end

Or for example:

def sqr x ; x*x end

etc.

Answer 3

Do this, though it's a bit naughty:

class Module
  def const_missing(m)
    const_set(m, Module.new)             
  end
end

module A::B
  def self.hello_my_friend
    :hello_my_friend
  end
end

A::B.hello_my_friend #=> :hello_my_friend    

Answer 4

Ruby doesn't use significant whitespace in the same way as Python does (though it can provide you with warnings if the indentation seems wonky), so you can simply not indent the code if you don't want to do so. It'd just make the code harder to read.

Incidentally, you may want to check whether four or five levels of modules indicates a code smell.