function parse(numStr) {
  var exponent = 0, digits, numberOfIntegerDigits;
  var i, j, zeros;

  // Decimal point?
  if ((numberOfIntegerDigits = numStr.indexOf(DECIMAL_SEP)) > -1) {
    numStr = numStr.replace(DECIMAL_SEP, '');
  }

  // Exponential form?
  if ((i = numStr.search(/e/i)) > 0) {
    // Work out the exponent.
    if (numberOfIntegerDigits < 0) numberOfIntegerDigits = i;
    numberOfIntegerDigits += +numStr.slice(i + 1);
    numStr = numStr.substring(0, i);
  } else if (numberOfIntegerDigits < 0) {
    // There was no decimal point or exponent so it is an integer.
    numberOfIntegerDigits = numStr.length;
  }

  // Count the number of leading zeros.
  for (i = 0; numStr.charAt(i) === ZERO_CHAR; i++) { /* empty */ }

  if (i === (zeros = numStr.length)) {
    // The digits are all zero.
    digits = [0];
    numberOfIntegerDigits = 1;
  } else {
    // Count the number of trailing zeros
    zeros--;
    while (numStr.charAt(zeros) === ZERO_CHAR) zeros--;

    // Trailing zeros are insignificant so ignore them
    numberOfIntegerDigits -= i;
    digits = [];
    // Convert string to array of digits without leading/trailing zeros.
    for (j = 0; i <= zeros; i++, j++) {
      digits[j] = +numStr.charAt(i);
    }
  }

  // If the number overflows the maximum allowed digits then use an exponent.
  if (numberOfIntegerDigits > MAX_DIGITS) {
    digits = digits.splice(0, MAX_DIGITS - 1);
    exponent = numberOfIntegerDigits - 1;
    numberOfIntegerDigits = 1;
  }

  return { d: digits, e: exponent, i: numberOfIntegerDigits };
}
Parse a number (as a string) into three components that can be used
for formatting the number.

(Significant bits of this parse algorithm came from https://github.com/MikeMcl/big.js/)

@param  {string} numStr The number to parse
@return {object} An object describing this number, containing the following keys:
 - d : an array of digits containing leading zeros as necessary
 - i : the number of the digits in `d` that are to the left of the decimal point
 - e : the exponent for numbers that would need more than `MAX_DIGITS` digits in `d`