Module MyMod::MyOtherMod question

Can someone please explain what the difference is?

A assumed these were synonymous, but they are not:

module A
module B

end
end

Not equivalent to?:

module A::B

end

Thanks alot.

Gene A. wrote:

[I] assumed these were synonymous, but they are not:

I stand corrected. It appears that in order to use the following syntax:

module A::B

end

module A must be defined.

Gene A. wrote:

Gene A. wrote:

[I] assumed these were synonymous, but they are not:

I stand corrected. It appears that in order to use the following syntax:

module A::B

end

module A must be defined.

Yes. But even then,

module A; end
module A::B

end

is different to

module A
module B

end
end

in the way that constants are looked up.

module A; FOO = 123; end
=> 123

module A::B
puts FOO
end
NameError: uninitialized constant A::b::FOO
from (irb):3
from :0

module A; module B
puts FOO
end; end
123
=> nil

The constant that classes are assigned to when defined may be prefixed
by the names of existing modules using the scope operator (::). When
this happens, the leading scope operator places the class or module in
the top-level scope.

Here is the example:

CONST = ‘outer’

module A
CONST = ‘inner’
end

module A
class B
def self.get_const
CONST
end
end
end

p A::B.get_const # => inner

Now, class B is inserted into module A’s namespace, but it’s not
interpreted in the context of A. As a result, the reference to CONST
resolves to the top-level constant, not A’s version.

class A::B
def self.get_const
CONST
end
end

p A::B.get_const # => outer

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