Base105 Encoding using all ASCII printable characters

base105.rb

module Base105
  EncChars = (' '..'~').to_a.flatten
  DecChars = begin
    dec = []
    EncChars.each_with_index{ |c, i| dec[c.ord] = i }
    dec
  end

  def self.encode(i)
    result = ''
    while (i, j = i.divmod(EncChars.size)) != [0,0]
      result << EncChars[j]
    end
    result.reverse
  end

  def self.decode(s)
    result = 0
    s.each_char do |c|
      result = result * EncChars.size + DecChars[c.ord]
    end
    result
  end
end

# usage:
# i=4371937102758371285789341768594106489305974329150
# puts i
# puts j=Base105.encode(i)
# puts Base105.decode(j)