public static <T extends Comparable<T>> Range<T> parse(String value, Function<String, T> parser) {
Validate.notNull(parser, "Parser is required");
if (StringUtils.isBlank(value) || StringUtils.equals(SEPARATOR, value)) {
return Ranges.all();
} else if (!StringUtils.contains(value, SEPARATOR)) {
T element = parser.apply(value);
return Ranges.atMost(element);
} else {
String lower = StringUtils.substringBefore(value, SEPARATOR);
String upper = StringUtils.substringAfter(value, SEPARATOR);
if (StringUtils.isBlank(lower)) {
// ..n
Pair<T, BoundType> boundary = parseUpperBoundary(upper, parser);
return Ranges.upTo(boundary.getLeft(), boundary.getRight());
} else if (StringUtils.isBlank(upper)) {
// n..
Pair<T, BoundType> boundary = parseLowerBoundary(lower, parser);
return Ranges.downTo(boundary.getLeft(), boundary.getRight());
} else {
// n..m
Pair<T, BoundType> down = parseLowerBoundary(lower, parser);
Pair<T, BoundType> up = parseUpperBoundary(upper, parser);
return Ranges.range(down.getLeft(), down.getRight(), up.getLeft(), up.getRight());
}
}
}
