/**
 * Utility function to allow high-precision decimals to work with the SQL layer.
 * Use as an unquoted %s parameter.
 */
function gmap_decimal($num) {
  // Paraphrased from postgresql documentation:
  //
  // Numbers in SQL can be in one of these forms:
  //   digits
  //   digits.[digits][e[+-]digits]
  //   [digits].digits[e[+-]digits]
  //   digitse[+-]digits
  // where "digits" is one or more decimal digits.

  // Trim extra whitespace
  $num = trim($num);
  // Check if we're in an acceptable form.
  if (preg_match('/^[+\-]?((\d+)|(\d+\.\d*)|(\d*\.\d+))(e[+\-]?\d+)?$/',$num)===1) {
    // Good, we can pass that right along.
    return $num;
  }
  // Otherwise, cast to float, possibly losing precision.
  return (float) $num;
}