From: Sean O'Halpin <sean.ohalpin@...>
Date: 2008-03-09T08:55:11+09:00
Subject: Re: A question on singleton methods

On Sat, Mar 8, 2008 at 11:34 PM, mike leonard <mikeleonard@gmail.com> wrote:
> Hello,
>
>  I have a hash full of objects, like so:
>
>     a_hash = { :a => "alpha", :b => "beta" }
>
>  I don't I need to define a singleton method for one of the items in
>  the class. I thought I could do:
>
>     def a_hash.fetch(:a).to_s
>         "ALPHA"
>     end
>
>  But all this gets me is a big fat error:
>
>     t.rb:2: syntax error, unexpected tSYMBEG, expecting ')'
>     def a_hash.fetch(:a).to_s
>                       ^
>
>  This is just a minimal example. In real life, the objects in the hash
>  have been generated programatically, so I don't have variable
>  references for them -- just the keys.
>
>  Is it possible that there is a way around this error? If not, is there
>  another way to do what I'm trying to do? I'm pretty new to this, so
>  apologies in advance if it is an obvious mistake.
>
>  Thank you,
>
>  Mike Leonard
>
>
You could try this:

a_hash = { :a => "alpha", :b => "beta" }

def (a_hash[:a]).to_s
  "ALPHA"
end

a_hash.each do |key, value|
  puts "#{key} = #{value.to_s}"
end
__END__
a = ALPHA
b = beta

Regards,
Sean