English Numerals

numerals.rb

#!/usr/bin/env ruby
require 'pp'

num = ARGV[0]
num = num.to_i

NUMBERS = {
  1 => 'one',
  2 => 'two',
  3 => 'three',
  4 => 'four',
  5 => 'five',
  6 => 'six',
  7 => 'seven',
  8 => 'eight',
  9 => 'nine',
  10 => 'ten',
  11 => 'eleven',
  12 => 'twelve',
  13 => 'thirteen',
  14 => 'fourteen',
  15 => 'fifteen',
  16 => 'sixteen',
  17 => 'seventeen',
  18 => 'eighteen',
  19 => 'nineteen',
  20 => 'twenty',
  30 => 'thirty',
  40 => 'fourty',
  50 => 'fifety',
  60 => 'sixty',
  70 => 'seventy',
  80 => 'eighty',
  90 => 'ninety',
}

def numerals(num)
  return '' unless num

  number = "%04d" % num

  thousand = number[0]
  hundered = number[1]
  remains  = number[2..3]

  thousand = thousand.to_i
  hundered = hundered.to_i
  remains  = remains.to_i

  thousand_text = if thousand == 0
                    ''
                  elsif thousand == 1
                    NUMBERS[thousand] + ' thousand'
                  else
                    NUMBERS[thousand] + ' thousands'
                  end
  hundered_text = if hundered == 0
                    ''
                  elsif hundered == 1
                    NUMBERS[hundered] + ' hundered'
                  else
                    NUMBERS[hundered] + ' hundereds'
                  end
  remains_text = if remains == 0
                   ''
                 elsif NUMBERS[remains]
                   NUMBERS[remains]
                 else
                   second, first = remains.to_s.split(//)
                   second = second.to_i * 10
                   first  = first.to_i

                   "%s-%s" % [NUMBERS[second], NUMBERS[first]]
                 end

  numerals_text = thousand_text
  numerals_text += ' and ' unless thousand_text.empty?
  numerals_text += hundered_text
  numerals_text += ' and ' unless hundered_text.empty?
  numerals_text += remains_text

  numerals_text
end

puts numerals(ARGV[0])