autocast.scala

/**
  * Attempts to parse a string and return a strongly-typed object.
  *     Supports Date, datetime, datetime with timezone, double, long and string
  * @param x a String to attempt to parse
  * @return Option[Any] a null-friendly container for the result. Some[Any] when match succeeded.  None when the match failed.
  */
def Cast(x: String): Option[Any] =
{
	val long_months = "(January|February|March|April|May|June|July|August|September|October|November|December)"
	val short_months = "(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)"
	val two_digit = """(\d\d)"""
	val four_digit = """(\d\d\d\d)"""
	val space = """ """
	val comma = ""","""
	val dash = """-"""

	val date =      (four_digit + dash + two_digit + dash + two_digit).r
	val date_nice_long = (long_months + """ (\d\d), (\d\d\d\d)""").r
	val date_mla = ("""(\d\d) """ + long_months + """ (\d\d\d\d)""").r
	val date_mla_short = ("""(\d\d) """ + short_months + """ (\d\d\d\d)""").r
	val datetime =  """(\d\d\d\d)-(\d\d)-(\d\d) (\d\d):(\d\d)""".r
	val datetimezone = """(\d\d\d\d)-(\d\d)-(\d\d) (\d\d):(\d\d) ([A-Z]+)""".r
	val double = """([-+]?[0-9]*\.[0-9]+|[0-9]+)""".r
	val long = """([-+]?[0-9]*)""".r
	val string = """(.*)""".r

	x match {
		case date(year, month, day) => Some(new SimpleDateFormat("yyyy-MM-dd").parse(x))
		case datetime(year, month, day, hours, minutes) => Some(new SimpleDateFormat("yyyy-MM-dd HH:mm").parse(x))
		case date_nice_long(month, day, year) => Some(new SimpleDateFormat("MMM dd, yyyy").parse(x))
		case date_mla(day, month, year) => Some(new SimpleDateFormat("dd MMM yyyy").parse(x))
		case date_mla_short(day, month, year) => Some(new SimpleDateFormat("dd MMM yyyy", Locale.US).parse(x))
		case datetimezone(year, month, day, hours, minutes, tz) => Some(new SimpleDateFormat("yyyy-MM-dd HH:mm z").parse(x))
		case long(i) if Long.MinValue <= i.toLong && i.toLong <= Long.MaxValue => Some(i.toLong)
		case double(d) => Some(d.toDouble)
		case string(string) => Some(string)
		case _ => None
	}
}