Hi --
How can I enumerate all the constants inside the module in the second
example?
Notice that #constants array is empty
See comments in code, below.
For bonus points, which is the "correct" eval method to use to define a
class inside the module (they all seem to work)
module_eval and class_eval are synonyms for each other. I'd use
module_eval over instance_eval, unless you specifically need instance
methods to be singleton methods on the module object (which is
unlikely, and can be achieved by other means under module_eval).
module Foo
class A
end
end
puts Foo.constants.inspect # => ["A"]
[:module_eval, :instance_eval, :class_eval].each do |method|
m = Module.new
m.send(method) do
class B
The constant B is resolved in the usual "semi-static", eager way,
which means it does not belong to the new module: it's actually being
defined at the top level.
end
end
puts m.constants.inspect # => (I would expect ['B'])
puts m.const_get('B').inspect # => B
end
Try this:
m = Module.new
m.module_eval do
class self::B # forces Ruby to wait to bind the constant
end
end
puts m.constants.inspect # ["B"]
puts m.const_get('B').inspect # #<Module:0x220164>::B
David
···
On Fri, 10 Oct 2008, Xavier Shay wrote:
--
Rails training from David A. Black and Ruby Power and Light:
Intro to Ruby on Rails January 12-15 Fort Lauderdale, FL
Advancing with Rails January 19-22 Fort Lauderdale, FL *
* Co-taught with Patrick Ewing!
See http://www.rubypal.com for details and updates!