gistfile1.rb

# exhibit a
    {:conditions => case f.to_s
      when 'active'   then {:state => @@states[2]}
      when 'disabled' then {:state => @@states[0..1]}
      when 'all'      then {}
      else                 {:state => @@states[3]}
    end}

# exhibit b
    case f.to_s
      when 'active'   then {:conditions => {:state => @@states[2]}}
      when 'disabled' then {:conditions => {:state => @@states[0..1]}}
      when 'all'      then {}
      else                 {:conditions => {:state => @@states[3]}}
    end