From: James Edward Gray II <james@...>
Date: 2007-01-22T05:22:43+09:00
Subject: Fwd: Please Forward: Ruby Quiz Submission

--Apple-Mail-1--22285100
Content-Transfer-Encoding: 7bit
Content-Type: text/plain;
	charset=US-ASCII;
	delsp=yes;
	format=flowed

Begin forwarded message:

> From: Phil Darnowsky <pdarnows@yahoo.com>
> Date: January 20, 2007 3:03:27 AM CST
> To: submission@rubyquiz.com
> Subject: Please Forward: Ruby Quiz Submission
>
> Attached please find my modest solution to #110, which is the first
> Rubyquiz I've bothered to submit, though I've been following the site
> for about two months now--thanks for the fun challenges!
>
> This solution doesn't pass the test suite for two reasons:
>
> (1) I think, instead of just returning an array of possible expansions
> in response to an ambiguous abbreviation, the Right Thing is to raise
> an exception that carries that array around inside it.  This is not
> what the test suite is expecting, but of course it's trivial to modify
> my solution to do that instead.
>
> (2) This fails the assertions in line 118 & 131.  I think that, even
> though @class#aa is not defined at the moment that it's passed to
> abbrev,  it's valid to allow it to be called through an  
> abbreviation at
> any time after it's defined.  You could also make the case, I suppose,
> that the abbreviation :a should preclude @class#aa from being invoked
> when a.a is called, but I'd consider this a pathological case to start
> with.  If this is the kinda thing you're going to go around doing, you
> shouldn't act surprised when you get weird results.
>
> Anyhow, I am going to bed--my girlfriend called in the middle of this
> e-mail and the first words out of her mouth were "Why aren't you
> asleep?" So I think I will.
>
> Thanks again,
>
> Phil Darnowsky
>
>
>
> ______________________________________________________________________ 
> ______________
> Cheap talk?
> Check out Yahoo! Messenger's low PC-to-Phone call rates.
> http://voice.yahoo.com
--Apple-Mail-1--22285100
Content-Transfer-Encoding: 7bit
Content-Type: application/x-ruby;
	x-unix-mode=0666;
	name=method_abbreviate.rb
Content-Disposition: attachment;
	filename=method_abbreviate.rb

class AmbiguousAbbreviationException < Exception
	# @candidates should get an array of symbols that the abbreviation
	# might expand to.
	
	def initialize(*candidates)
		super
		@candidates = candidates
	end

	attr_reader :candidates
end

class Module
	def abbrev(*meths)

		# Do abbrev setup once.
		
		unless (@abbrev_setup_done) then
			@abbrev_expansions = Hash.new([])
			self.class.send(:attr_reader, :abbrev_expansions)

			module_eval do 
				def method_missing(symbol, *args)
					candidates = self.class.abbrev_expansions[symbol.to_sym].dup
					candidates.delete_if {|meth| !(respond_to?(meth))}

					case 
						when candidates.size == 0:
							raise(NoMethodError)
						when candidates.size == 1:
							send(candidates.first, *args)
						else
							raise(AmbiguousAbbreviationException.new(candidates))
					end
				end
			end

			@abbrev_setup_done = true
		end

		# Build hash of possible expansions.

		module_eval do
			meths.each do |meth|
				sym = meth.to_sym
				prefix = meth.to_s

				while (prefix.length > 0) do
					prefix_sym = prefix.to_sym
					@abbrev_expansions[prefix_sym] += [sym]
					prefix.chop!
				end
			end
		end
	end
end

--Apple-Mail-1--22285100
Content-Transfer-Encoding: 7bit
Content-Type: text/plain;
	charset=US-ASCII;
	format=flowed



--Apple-Mail-1--22285100--