From: ara.t.howard@...
Date: 2006-04-11T22:46:40+09:00
Subject: Re: define_singleton_method(a_symbol,&block)

On Tue, 11 Apr 2006, Bill Kelly wrote:

> Hi,
>
> I was wondering what was the idiomatic way to do this:
>
> class BigDipper
>   def little_dipper(a_symbol)
>     define_singleton_method(a_symbol) {
>       "#{a_symbol} is double-helix"
>     }
>   end
> end
> 
> s_ = BigDipper.new
> s_.little_dipper(:DNA)
> s_.DNA
>   => "DNA is a double-helix"
>
> q_ = BigDipper.new
> q_.respond_to? :DNA
>   => false


harp:~ > cat a.rb
class BigDipper
   def self.little_dipper(a_symbol)
     define_method(a_symbol) { "#{a_symbol} is double-helix" }
   end
   def little_dipper(*a, &b) self.class.little_dipper(*a, &b) end
end

s_ = BigDipper.new
s_.little_dipper(:DNA)
p s_.DNA

q_ = BigDipper.new
p q_.respond_to?(:DNA)

BigDipper.little_dipper 'DNA2'
p s_.respond_to?('DNA2')
p q_.respond_to?('DNA2')


harp:~ > ruby a.rb
"DNA is double-helix"
true
true
true

hth.

-a
-- 
be kind whenever possible... it is always possible.
- h.h. the 14th dali lama