Question

I want to extract some string data from a given file. File got structure such as:

---

name, catg, {y:2006, v:1000, c:100, vt:1}, {y:2007, v:1000, c:100, vt:1},.. {..}...

---

I want to extract next values:

• name;
• catg;
• numbers after y, v, c, vt labels;

---

I used the next regexes:

• @"(?<name>\w+), (?<cat>\w+)" for extraction of the first two items;
• @"(?:\{y:(?<y>\d+), +v:(?<v>\d+), +c:(?<c>\d+), +vt:(?<vt>\d+)\}, ?)+" for extraction of other values enclosed in curly brackets.

I concatenated those two and made a test in regex tester. But as expected I get only one set of extracted numbers. And I need result from the other part ({y:2007, v:1000, c:100, vt:1}). Moreover there could be more than two parts.

How do I fix my regex? And then how do I collect all number sets from corresponding parts.

Answer 1

Here’s fixed regex (you need to specify IgnorePatternWhitespace option):

(?'name'\w+), \s*
(?'category'\w+), \s*
(?:
    \{ \s*
        y: (?'y'\d+), \s*
        v: (?'v'\d+), \s*
        c: (?'c'\d+), \s*
        vt: (?'vt'\d+)
    \} \s*
    ,? \s*
)*

And here’s usage:

String input = @"name, catg, {y:2006, v:1000, c:100, vt:1}, {y:2007, v:1000, c:100, vt:1}";
String pattern =
      @"(?'name'\w+), \s*
        (?'category'\w+), \s*
        (?:
            \{ \s*
                y: (?'y'\d+), \s*
                v: (?'v'\d+), \s*
                c: (?'c'\d+), \s*
                vt: (?'vt'\d+)
            \} \s*
            ,? \s*
        )* ";
RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Singleline;

Match match = Regex.Match(input, pattern, options);
if (match.Success)
{
    String name = match.Groups["name"].Value;
    String category = match.Groups["category"].Value;

    Console.WriteLine("name = {0}, category = {1}", name, category);

    for (Int32 i = 0; i < match.Groups["y"].Captures.Count; ++i)
    {
        Int32 y = Int32.Parse(match.Groups["y"].Captures[i].Value);
        Int32 v = Int32.Parse(match.Groups["v"].Captures[i].Value);
        Int32 c = Int32.Parse(match.Groups["c"].Captures[i].Value);
        Int32 vt = Int32.Parse(match.Groups["vt"].Captures[i].Value);

        Console.WriteLine("y = {0}, v = {1}, c = {2}, vt = {3}", y, v, c, vt);
    }
}