36進数で英文を書いてみる

base36utils.rb

# 36進数でちょっと遊ぶ (簡単な英文を書く)
# http://qiita.com/manuluu/items/ad2c471a1a1c6fd91a63

module Base36Utils
  def get_symbols(str)
    syms = str.scan(/[^a-zA-Z]/).uniq.sort.join
  end

  def to_base36(base10, symbols="")
      base10.to_s(36).gsub(/\d/){|d|symbols[d.to_i]}
  end

  def to_base10(base36, symbols="")
      base36.gsub(/[#{symbols}]/){|c|symbols.index(c)}.to_i(36)
  end
end

usage.rb

require_relative 'base36utils'

include Base36Utils

str = "I thought what I'd do was, I'd pretend I was one of those deaf-mutes"

syms = get_symbols(str)

base10 = to_base10(str, syms)
base36 = to_base36(base10, syms)

print "original: "; p str
#=> "I thought what I'd do was, I'd pretend I was one of those deaf-mutes"
print "symbols: "; p syms
#=> " ',-"

puts
puts "encoded (base10): "; p base10
#=> 3373562398143598293391832131714159190003724948263861387893016685268379127404427353734077228848031196783204
puts "decoded (base36): "; p base36
#=> "i thought what i'd do was, i'd pretend i was one of those deaf-mutes"