Means of Optional Expression

Ruby
1

Have a look at this. Note that I’m not bothering to implement the
#shuffle method as it is not the point --it’s just an foo example.

module Kernel
def express(name)
extend self.class.const_get(name.to_s.capitalize)
end
end

class Array
module Random
def shuffle
[] # …
end

  def shuffle!
    replace(shuffle)
  end

  # ...
end

end

a = [1,2,3]
a.shuffle #=> NoMethodError

a.express(:Random)
a.shuffle #=> []

T.

2

On Jun 18, 1:48 pm, Trans [email protected] wrote:

    [] # ...

a = [1,2,3]
a.shuffle #=> NoMethodError

a.express(:Random)
a.shuffle #=> []

FYI. I’m thinking about using this approach for Facets’ Core
extensions in 2.0. There would be two versions of each require, one
that automatically includes the extension and one that does not.

T.

3

On 6/18/07, Trans [email protected] wrote:

class Array
end
that automatically includes the extension and one that does not.

T.

I don’t see it being worth it really. a.extend(Array::Random); a.shuffle
What is this buying you? (Besides 6 characters, anyway)

4

On 6/18/07, Logan C. [email protected] wrote:

I don’t see it being worth it really. a.extend(Array::Random); a.shuffle
What is this buying you? (Besides 6 characters, anyway)

I like it. Does anybody see a potential problem for this unobtrusive
‘opening’ of the class?

Todd

5

On Jun 18, 4:31 pm, “Logan C.” [email protected] wrote:

I don’t see it being worth it really. a.extend(Array::Random); a.shuffle
What is this buying you? (Besides 6 characters, anyway)

Besides being more concise, it also limits us to valid choices. Of
course we can always use extend, but a.extend(String::Random) would
more than likely make a mess of things, and might not even die early
causing peculiar hard to track bugs.

T.