Nesting Includes

Ruby
1

Hi. I’d like to include one module, which would include other modules
into my namespace. Is this doable?

Doing this:
----file1.rb
module AAA
include bbb
end

----file2.rb
include AAA

does not seem to include bbb. Is there anyway to do this, or do I need
to add the include explicilty to file2 as well?

(Note - I understand the need for this, to avoid namespace collisions).

2

On 11/15/05, [email protected] [email protected] wrote:

include AAA

does not seem to include bbb. Is there anyway to do this, or do I need
to add the include explicilty to file2 as well?

Hi, you need to require the files you want:

----bbb.rb
module BBB
def bbb
puts “bbb”
end
end

----aaa.rb
require ‘bbb’

module AAA
include BBB
end

---- test-nested-includes.rb
require ‘aaa’
include AAA
bbb

---- OUTPUT
bbb

Regards,

Sean

3

On Nov 14, 2005, at 8:07 PM, [email protected] wrote:

does not seem to include bbb. Is there anyway to do this, or do I
need
to add the include explicilty to file2 as well?

It seems like you are thinking (in the way that I did while learning
Ruby)
that Ruby’s ‘include’ facility is analogous to the C/C++ include
mechanism.
Same keyword but totally unrelated semantics.

As Sean indicated, use ‘require’ to have ruby parse a file and use
‘include’
to mixin modules (i.e. to dynamically construct the hierarchy of
modules/classes).
You have to make sure that Ruby has parsed a module definition via
‘require’ before
it will be available for use via ‘include’. If your modules were all
defined
in a single file, it would look like:

module B

definition of module B

end

module A
include B

more parts of A

end

include A

So if B is defined in ‘file1.rb’ and A is defined in ‘file2.rb’ you
could
access those definitions in a third file as:

require 'file1'    # now B is defined, for use by A
require 'file2'    # now A is defined, using B

include A	   # module A is included into the current scope (top level)

Gary W.