module Base62

# File lib/base62-rb.rb, line 23
def self.decode(str)
  num = 0
  i = 0
  len = str.length - 1
  # while loop is faster than each_char or other 'idiomatic' way
  while i < str.length
    pow = BASE**(len - i)
    num += KEYS_HASH[str[i]] * pow
    i += 1
  end
  num
end

# File lib/base62-rb.rb, line 9
def self.encode(num)
  return "0" if num == 0
  return nil if num < 0

  str = ""
  while num > 0
    # prepend base62 charaters
    str = KEYS[num % BASE] + str
    num = num / BASE
  end
  str
end