/**
* Parses a formatted string representing the frequency.
*
* <p>The format can either be based on ISO-8601, such as 'P3M' or without the 'P' prefix e.g.
* '2W'.
*
* <p>The period must be positive and non-zero.
*
* @param toParse the string representing the frequency
* @return the frequency
* @throws IllegalArgumentException if the frequency cannot be parsed
*/
@FromString
public static Frequency parse(String toParse) {
ArgChecker.notNull(toParse, "toParse");
if (toParse.equalsIgnoreCase("Term")) {
return TERM;
}
String prefixed = toParse.startsWith("P") ? toParse : "P" + toParse;
try {
return Frequency.of(Period.parse(prefixed));
} catch (DateTimeParseException ex) {
throw new IllegalArgumentException(ex);
}
}
