public static IEnumerable<int> ToDiapason([NotNull] this string s, int min, int max) {
if (s == null) throw new ArgumentNullException(nameof(s));
if (max < min) throw new ArgumentOutOfRangeException(nameof(max));
return s.Split(',', ';').Select(x => x.Trim()).SelectMany(part => {
int n = part.IndexOf('-'), fromValue, toValue;
if (n == 0) {
var m = part.IndexOf('-', n + 1);
if (m != -1 && m != 1) {
n = m;
}
}
if (n > 0 && n < part.Length - 1) { // "x-y"
if (FlexibleParser.TryParseInt(part.Substring(0, n), out fromValue) &&
FlexibleParser.TryParseInt(part.Substring(n + 1), out toValue)) {
fromValue = Math.Max(fromValue, min);
return Enumerable.Range(fromValue, 1 + Math.Min(toValue, max) - fromValue);
}
} else if (n < 0) { // "x"
if (FlexibleParser.TryParseInt(part, out fromValue) && fromValue >= min && fromValue <= max) {
return new[] { fromValue };
}
} else if (part.Length == 1) { // "-"
return Enumerable.Range(min, 1 + max - min);
} else if (n == part.Length - 1) { // "x-"
if (FlexibleParser.TryParseInt(part.Substring(0, n), out fromValue)) {
fromValue = Math.Max(fromValue, min);
return Enumerable.Range(fromValue, 1 + max - fromValue);
}
} else { // "-x"
if (FlexibleParser.TryParseInt(part.Substring(n + 1), out toValue)) {
return Enumerable.Range(min, 1 + Math.Min(toValue, max) - min);
}
}
return new int[0];
});
}
}
