Feature #10018: Consider adding Sub-Includes as in include Foo::bar

• Status: Feedback
• Priority: Normal
• Assignee: -
• Target version: -

[shevegen (Robert A. Heiler)]

On IRC someone asked a nice question:

<arup_r> If I write class Foo; include Enumerable; end This code include all methods from Enumerable. But suppose I want to include #all?, #any? .. What's the way to include only required methods ?

This prompted me to write this.

What if ruby would allow us to include just singular methods?

Something like:

include Enumerable::any?

And so forth, so that we could cherry-pick what we want.

This is already possible in some projects, like facets.

But I think they solve it by splitting up the whole
stuff into individual files, and then including
this.

I think it would be nicer if include itself would
support a scope-mechanic.

[shevegen (Robert A. Heiler)]

Oops sorry!

This is not a bug, it is a feature request.

I am not sure how to move it to features now, sorry. :(

[nobu (Nobuyoshi Nakada)]

• Tracker changed from Bug to Feature
• Description updated (diff)
• Status changed from Open to Feedback

You can achieve it by "method transplanting".

class Foo
  define_method(:any?, Enumerable.instance_method(:any?))
end

Wrapper method like Module#mix may help you.
http://www.slideshare.net/yukihiro_matz/rubyconf-2010-keynote-by-matz

It has been removed finally, you can construct

[matz (Yukihiro Matsumoto)]

And method transplanting only works when the method does not call super nor other Enumerable methods.
Automatic resolving is possible, but it would make inclusion far more complex.

Matz.