Does C# have built-in support for parsing page-number strings?

Question

Does C# have built-in support for parsing strings of page numbers? By page numbers, I mean the format you might enter into a print dialog that\'s a mixture of comma and das

Answer 1

Here's something I cooked up for something similar.

It handles the following types of ranges:

1        single number
1-5      range
-5       range from (firstpage) up to 5
5-       range from 5 up to (lastpage)
..       can use .. instead of -
;,       can use both semicolon, comma, and space, as separators

It does not check for duplicate values, so the set 1,5,-10 will produce the sequence 1, 5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

public class RangeParser
{
    public static IEnumerable Parse(String s, Int32 firstPage, Int32 lastPage)
    {
        String[] parts = s.Split(' ', ';', ',');
        Regex reRange = new Regex(@"^\s*((?\d+)|(?\d+)(?(-|\.\.))(?\d+)|(?(-|\.\.))(?\d+)|(?\d+)(?(-|\.\.)))\s*$");
        foreach (String part in parts)
        {
            Match maRange = reRange.Match(part);
            if (maRange.Success)
            {
                Group gFrom = maRange.Groups["from"];
                Group gTo = maRange.Groups["to"];
                Group gSep = maRange.Groups["sep"];

                if (gSep.Success)
                {
                    Int32 from = firstPage;
                    Int32 to = lastPage;
                    if (gFrom.Success)
                        from = Int32.Parse(gFrom.Value);
                    if (gTo.Success)
                        to = Int32.Parse(gTo.Value);
                    for (Int32 page = from; page <= to; page++)
                        yield return page;
                }
                else
                    yield return Int32.Parse(gFrom.Value);
            }
        }
    }
}