Newbie question about Pickaxe example


#1

Hi to everyone,

I’m just approaching ruby (so far I like it) coming from Python and
other OO languages.

I’ve bought the new edition of the famous “Pickaxe” book and I’m having
a little difficulties understanding a piece of code.

There’s a paragraph (on page 354 for those who have that book) about
“Module Definitions” which contains the following snippet of code:

CONST=“outer”
module Mod
CONST=1
def Mod.method1()
CONST + 1
end
end

module Mod::Inner
def (Mod::Inner).method2()
CONST + " scope"
end
end

well, this last part is the one causing me difficulties.

“::” is the scope resolutor, and so far so good, but “Mod::Inner” what
is it?
“Inner” ought to be a constant judging from the name conventions.
Is it a predefinite one, or what?

I imagine that the definition under “Mod::Inner” are meant to insert
“method2” in the module “Mod”. Just can’t figure why “Mod::Inner”.

Thanks in advance for your help.

Regards,
Carmine M.


#2

“C” == Carmine M. removed_email_address@domain.invalid writes:

C> module Mod::Inner

here it define the module Inner under the module Mod

C> def (Mod::Inner).method2()

it define a method for this module (Mod::Inner)

C> CONST + " scope"
C> end
C> end

it’s written like this, to see the difference with this

module Mod
module Inner
def self.method2
CONST + “scope”
end
end
end

Mod::Inner.method2 # in `+’: String can’t be coerced into Fixnum

Guy Decoux


#3

Hi Guy,

Thanks for your clarification. It’s clear now.

Regards,
Carmine M.