Constant Resolution Confusion

ruby-talk
1

I was surprised by the following this weekend:

  module Foo
    module Bar; end
    class Whee1
      include Bar
    end
  end
  # All is well

  class Foo::Whee2
    include Bar
  end
  #=> uninitialized constant Foo::Whee2::Bar (NameError)

Is the answer simply "lexically scoped resolution"?

Is the above still the case with 1.9?

2

Yuck..
And yes "problem" persists with Ruby1.9.

···

On Tue, 2007-12-18 at 03:10 +0900, Phrogz wrote:

I was surprised by the following this weekend:

  module Foo
    module Bar; end
    class Whee1
      include Bar
    end
  end
  # All is well

  class Foo::Whee2
    include Bar
  end
  #=> uninitialized constant Foo::Whee2::Bar (NameError)

Is the answer simply "lexically scoped resolution"?

Is the above still the case with 1.9?

--
Let them talk of their oriental summer climes of everlasting
conservatories; give me the privilege of making my own summer with my
own coals.

http://gnufied.org

3

Maybe it's because (I assume) this is a paired-down example, but in
the example class Whee1 is in the scope of module Foo, and so is
module Bar, but module Bar isn't in the scope of class Foo::Whee2, so
you have to include it as qualified Foo::Bar. It doesn't look like
module Bar is lexically scoped to class Foo.

Regards,
Jordan

···

On Dec 17, 12:07 pm, Phrogz <phr...@mac.com> wrote:

I was surprised by the following this weekend:

  module Foo
    module Bar; end
    class Whee1
      include Bar
    end
  end
  # All is well

  class Foo::Whee2
    include Bar
  end
  #=> uninitialized constant Foo::Whee2::Bar (NameError)

Is the answer simply "lexically scoped resolution"?

Is the above still the case with 1.9?

4

The actual situation was that I started writing code all nested as in
the first example. Everything was working, my unit tests were passing,
all was right with the world.

But I didn't like the nesting. The extra level of folding was getting
in the way, and the non-explicit nesting made my function pop up not
the way I wanted.

So I changed the code in a way that I thought was purely formatting; I
pulled the classes (and modules) out to the top level with an explicit
Foo:: prefix for each. And I was surprised when my code stopped
working.

It was simple enough to see the error, and not very painful to find
all the cases where I had included the module and also add the Foo::
prefix. But it surprised me. Despite likely reading about this issue
previously, I had thought constant resolution would not be affected by
that particular edit.

*shrug*

···

On Dec 17, 11:47 am, MonkeeSage <MonkeeS...@gmail.com> wrote:

On Dec 17, 12:07 pm, Phrogz <phr...@mac.com> wrote:

> I was surprised by the following this weekend:

> module Foo
> module Bar; end
> class Whee1
> include Bar
> end
> end
> # All is well

> class Foo::Whee2
> include Bar
> end
> #=> uninitialized constant Foo::Whee2::Bar (NameError)

> Is the answer simply "lexically scoped resolution"?

> Is the above still the case with 1.9?

Maybe it's because (I assume) this is a paired-down example, but in
the example class Whee1 is in the scope of module Foo, and so is
module Bar, but module Bar isn't in the scope of class Foo::Whee2, so
you have to include it as qualified Foo::Bar. It doesn't look like
module Bar is lexically scoped to class Foo.