Modules and methods

[Javier Valencia]

Explaine this to me please:

module MyMod

def mymethod
puts "hello"
priv_method
end

def priv_method
puts "world"
end

private riv_method

end

MyMod.mymethod

undefined method `priv_method' for MyMod:Module (NoMethodError)

 

[Robert Klemme]

Explaine this to me please:

module MyMod

def mymethod
puts "hello"
priv_method
end

def priv_method
puts "world"
end

private riv_method

end

MyMod.mymethod

undefined method `priv_method' for MyMod:Module (NoMethodError)

You're defining instance methods, i.e. if you create an instance of a
class that includes MyMod it will have these methods.

You probably want singleton methods of the module:

module MyMod
class <<self
def mymethod
puts "hello"
priv_method
end

def priv_method
puts "world"
end

private riv_method
end
end
hello
world
=> nil

Kind regards

robert

 

[Javier Valencia]

Explaine this to me please:

module MyMod

def mymethod
puts "hello"
priv_method
end

def priv_method
puts "world"
end

private riv_method

end

MyMod.mymethod

undefined method `priv_method' for MyMod:Module (NoMethodError)

Sorry, mymethod definition is -> def MyMod.mymethod.

The result is the same

 

[Brian Schröder]

Sorry, mymethod definition is -> def MyMod.mymethod.

The result is the same

How about:
--8<---
#!/usr/bin/ruby -wd

module MyMod

def MyMod.mymethod
puts "hello"
priv_method
end

private
def MyMod.priv_method
puts "world"
end

end

MyMod.mymethod
--8<---

regards,

Brian

 

[Javier Valencia]

How about:
--8<---
#!/usr/bin/ruby -wd

module MyMod

def MyMod.mymethod
puts "hello"
priv_method
end

private
def MyMod.priv_method
puts "world"
end

end

MyMod.mymethod
--8<---

regards,

Brian

Yeah, i know that way, but why i have to use MyMod name into MyMod
itself, it looks ugly

 

[Javier Valencia]

Yeah, i know that way, but why i have to use MyMod name into MyMod
itself, it looks ugly

well, the correct question is why can't i use the method without MyMod
precedence?

 

[Javier Valencia]

Just another example:

-------------------
module MyMod

def MyMod.mymethod
puts "hello"
priv_method
end

private
def MyMod.priv_method
puts "world"
end


end

MyMod.priv_method

outputs: "world"

 

[ts]

J> private
J> def MyMod.priv_method
J> puts "world"
J> end

You have written something like this

private
class << self
def priv_method
puts "world"
end
end

i.e. private was the default for the module but not for the singleton
class.


Guy Decoux

 

[Brian Schröder]

J> private
J> def MyMod.priv_method
J> puts "world"
J> end

You have written something like this

private
class << self
def priv_method
puts "world"
end
end

i.e. private was the default for the module but not for the singleton
class.

aha, that means:

#!/usr/bin/ruby -wd

module MyMod

def MyMod.mymethod
puts "hello"
priv_method
end

class << self
private
def priv_method
puts "world"
end
end

end

MyMod.mymethod => "Hello World"

MyMod.priv_method => Error, private method

would be the correct way to define it?

regards,

Brian

 

[ts]

"B" == =?ISO-8859-1?Q?Brian Schr=F6der?= <ISO-8859-1> writes:

B> would be the correct way to define it?

yes, you can do it like this. This is the same than when you want to define
an accessor (attr_...) for the "singleton" class


Guy Decoux

 

[Javier Valencia]

B> would be the correct way to define it?

yes, you can do it like this. This is the same than when you want to define
an accessor (attr_...) for the "singleton" class


Guy Decoux

Never seen such way in documentation!
There should be an api change to allow a more "user friendly" way to do
things?

 

[ts]

J> Never seen such way in documentation!

documentation is just for anglois


Guy Decoux

 

[Javier Valencia]

I see that with instance methods happens the same:

module MyMod

def mymethod
puts "hello"
priv_method
end

private
def priv_method
puts "world"
end

end

include MyMod

priv_method

 

[ts]

J> priv_method

In ruby, a private method is a method that you must call *without* a
receiver (like in your example)

In your case, try

self.priv_method

and you'll see that ruby will give an error.


Guy Decoux

 

[Javier Valencia]

J> priv_method

In ruby, a private method is a method that you must call *without* a
receiver (like in your example)

In your case, try

self.priv_method

and you'll see that ruby will give an error.


Guy Decoux

So it works only for heritance if i can understand.
Shouldn't it work for all cases, not only heritance?

 

[ts]

J> So it works only for heritance if i can understand.
J> Shouldn't it work for all cases, not only heritance?

I have not understood, sorry.

Can you give what is the definition of private for you ?


Guy Decoux

 

[Malte Milatz]

Javier Valencia:

There should be an api change to allow a more "user friendly" way to do
things?

Well, the purposes of a module are mainly

- being a name space for classes
- gathering together methods, which then can be mixed into classes.

Extensive use of module methods (def MyModule.my_method) are often an
indication for a functional (or at least: unusual) programming style, that
is, not what Ruby is really for. So it's quite understandable that it's a
little involved to use them extensively.

That's my opinion, anyway.

Malte

 

[Brian Schröder]

I see that with instance methods happens the same:

module MyMod

def mymethod
puts "hello"
priv_method
end

private
def priv_method
puts "world"
end

end

include MyMod

priv_method

If I understand it correctly, then including MyMod into Object, makes
priv_method a private method of Object. So when you call priv_method
inside of object it can access it.

If you try to do

include MyMod

self.priv_method

it will throw an error, because priv_method is private. Maybe it all
can become clearer if you include MyMod into another class than Object
because you are doing things implicitly here.

HTH,

Brian

 

[Javier Valencia]

J> So it works only for heritance if i can understand.
J> Shouldn't it work for all cases, not only heritance?

I have not understood, sorry.

Can you give what is the definition of private for you ?


Guy Decoux

I mean that you can't use that method anywere at anytime, only within
the module or class.
This is the c++ way

 

[ts]

J> This is the c++ way

this is what I wanted to hear : perhaps now it's time to you to learn the
ruby way ))


Guy Decoux