'use strict';

var alphabet = [
  '0', '1', '2', '3', '4', '5', '6', '7',
  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
  'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
  'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
  'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
  'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l',
  'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
  'u', 'v', 'w', 'x', 'y', 'z', '-', '_'
];

var length = alphabet.length
  , map = {}
  , seed = 0
  , i = 0
  , prev;

/**
 * Return a string representing the specified number.
 *
 * @param {Number} num The number to convert.
 * @returns {String} The string representation of the number.
 * @api public
 */
function encode(num) {
  var encoded = '';

  do {
    encoded = alphabet[num % length] + encoded;
    num = Math.floor(num / length);
  } while (num > 0);

  return encoded;
}

/**
 * Return the integer value specified by the given string.
 *
 * @param {String} str The string to convert.
 * @returns {Number} The integer value represented by the string.
 * @api public
 */
function decode(str) {
  var decoded = 0
    , i = 0;

  while (i < str.length) {
    decoded = decoded * length + map[str.charAt(i)];
    i++;
  }

  return decoded;
}

/**
 * Yeast: A tiny growing id generator.
 *
 * @returns {String} A unique id.
 * @api public
 */
function yeast() {
  var now = encode(+new Date());

  if (now !== prev) return seed = 0, prev = now;
  return now +'.'+ encode(seed++);
}

//
// Map each character to its index.
//
while (i < length) {
  map[alphabet[i]] = i;
  i++;
}

//
// Expose the `yeast`, `encode` and `decode` functions.
//
yeast.encode = encode;
yeast.decode = decode;
module.exports = yeast;

'use strict';

var alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_'.split('')
  , length = 64
  , map = {}
  , seed = 0
  , i = 0
  , prev;

/**
 * Return a string representing the specified number.
 *
 * @param {Number} num The number to convert.
 * @returns {String} The string representation of the number.
 * @api public
 */
function encode(num) {
  var encoded = '';

  do {
    encoded = alphabet[num % length] + encoded;
    num = Math.floor(num / length);
  } while (num > 0);

  return encoded;
}

/**
 * Return the integer value specified by the given string.
 *
 * @param {String} str The string to convert.
 * @returns {Number} The integer value represented by the string.
 * @api public
 */
function decode(str) {
  var decoded = 0;

  for (i = 0; i < str.length; i++) {
    decoded = decoded * length + map[str.charAt(i)];
  }

  return decoded;
}

/**
 * Yeast: A tiny growing id generator.
 *
 * @returns {String} A unique id.
 * @api public
 */
function yeast() {
  var now = encode(+new Date());

  if (now !== prev) return seed = 0, prev = now;
  return now +'.'+ encode(seed++);
}

//
// Map each character to its index.
//
for (; i < length; i++) map[alphabet[i]] = i;

//
// Expose the `yeast`, `encode` and `decode` functions.
//
yeast.encode = encode;
yeast.decode = decode;
module.exports = yeast;

Reduce the size of the library