What is a module in Ruby? Is there any standard (any strict rules) to define module?

Ruby
1

What is a module in Ruby?

For now I can’t see any standard that could help me to define a module.

They say that “a module == a directory”. But that’s not true.
In Rails they define modules just as they want. Some are bound with a
directory with the same name, others are just plain files.

E.g. in ActiveRecord there is a line:

autoload :SessionStore

So session_store has to be:

  1. a module
  2. a directory with the same name (/session_store/*)

But session_store is:

  1. a class
  2. and a simple file, no any directory.

And there are many more similar examples.

So where is the standard of module definition in Ruby? What are the
rules?

2

On Fri, May 10, 2013 at 2:15 PM, Wins L. [email protected] wrote:

So where is the standard of module definition in Ruby? What are the
rules?

–
Posted via http://www.ruby-forum.com/.

In Ruby, very simply, a Module defines a scope and a namespace. But
that is hugely simplistic. I highly recommend reading “Metaprogramming
Ruby” for some real insight on this, as well as the good old pickaxe
book.

There are many fine additional references at the end of

3

On May 11, 2013 5:19 AM, “Wins L.” [email protected] wrote:

autoload :SessionStore

So where is the standard of module definition in Ruby? What are the
rules?

Just an aside: a filesystem directory is one type of directory, but not
all
dirctories are filesystem directories.

In the general sense, a directory is a searchable list of the names of
things and references to the things themselves (or “directions” on how
to
access them).

E.g. a map of filename => inode, or name => phone number, or symbol =>
function.

As has been mentioned elsewhere, a module is an object that holds
functions. You can use it to group related functions, and refer to them
in
a meaningful way, such as the ‘Math’ object in javascript.

You can also use modules to define or call functions with the same name
as
other/existing fucctions without creating ambiguity (namespacing).

Also, you can “mix” a module into a class, so that object instances of
that
class inherit the funtions as methods.

Sent from my phone, so excuse the typos.