fibonacci

cli.rb

module Ex8 
  class Cli 

    def initialize(options={})
      @options = options
    end 

    def run 
      length = @options[:length].to_i
      @output = []
      length.times do |n| 
        @output << fibo(n)
      end 
      p @output
    end 

    def fibo(n)
      return @output[n] if @output[n]
      n < 2 ? n : fibo(n - 1) + fibo(n - 2)
    end 

=begin
    def run
      length = @options[:length].to_i
      output = []
      (0..length).inject([1,0]){ |m, i| output << m[1]; [m[1], m[0] + m[1]] }
      p output
    end
=end
  end 
end

ex8

#!/bin/env ruby

require 'pathname'
require 'optparse'

root = Pathname.new(__FILE__).realpath.parent.parent
$:.unshift root.join('lib') if $0 == __FILE__

require 'ex8'

def help
  <<-BANNER
  Useage:
    ...
  BANNER 
end

opts = {
  :length => nil,
}

parser = OptionParser.new
parser.on('-l v', '--length v') { |v| opts[:length] = v }
parser.on('-v', '--version')    { puts Ex8::VERSION; exit }
parser.on_tail('-h', '--help')  { puts help; exit }

args = ARGV.dup
begin
  parser.parse!(args)
rescue OptionParser::MissingArgument,
       OptionParser::InvalidArgument,
       OptionParser::InvalidOption
  puts help
  exit
end

begin
  ui = Ex8::Cli.new(opts)
  ui.run
rescue Interrupt
  puts
end

ex8.rb

require 'ex8/cli'
require 'ex8/version'

module Ex8
end