On 9/19/07, August Lilleaas <augustlilleaas / gmail.com> wrote:
> I got this idea of a sort of neat syntatic sugar of bang (foo!) and
> question (foo?) methods. Take a look at this pastie:
> http://pastie.caboo.se/98638
>
> The idea is that you'll have two keywords added to Ruby - bang_given?
> and question_given?. Similar to block_given?.
>
> In this pastie, the method "finish" will not call save, as bang_given?
> isn't true. If you call "finish!", though, b ang_given will return true,
> and save will be called.
>
> Same thing with question_given?. Question given would be the least
> useful of them, though.
>
> And yes, doing def finish!; finish; save; is pretty easy, and this is
> not the sort of thing that should have max priority. It would still be a
> nice addition to the code-design useability of Ruby, though, as having
> 10 "def finish!; finish; save;"-ish methods is pretty boring.

It doesn't seem to carry it's own weight so as to merit the
fundamental change to ruby semantics it implies.  Ruby would need to
magically turn a finish! call into a finish call and arrange to return
true for bang_given?

If it really bothers you to write those finish! methods for YOUR
classes, why not do a little work with method_missing or a class
method to generate the pair which could be done without affecting the
language or the base classes?

For example:

shadowfax:~/Documents rick$ cat magic_bang.rb
module MagicBang

  def method_missing(msg, *args, &blk)
    msg.to_s.sub(/(.+)!$/) do
      __send__($1, *args, &blk)
      return save
    end
    super
  end
end

class TestClass
  include MagicBang

  def finish
    puts "Finish called"
  end

  def save
    puts "save called"
  end
end

puts "Calling finish method"
TestClass.new.finish
puts
puts "Calling finish! method"
TestClass.new.finish!
shadowfax:~/Documents rick$ ruby magic_bang.rb
Calling finish method
Finish called

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/