Question

I am a complete newb when it comes to regex, and would like help to make an expression to match in the following:

 {ValidFunctionName}({parameter}:"{value}")

 {ValidFunctionName}({parameter}:"{value}",
                     {parameter}:"{value}")

 {ValidFunctionName}()

Where {x} is what I want to match, {parameter} can be anything $%”$ for example and {value} must be enclosed in quotation marks.

ThisIsValid_01(a:"40")

would be “ThisIsValid_01”, “a”, “40”

ThisIsValid_01(a:"40", b:"ZOO")

would be “ThisIsValid_01”, “a”, “40”, “b”, “ZOO”

01_ThisIsntValid(a:"40")

wouldn’t return anything

ThisIsntValid_02(a:40)

wouldn’t return anything, as 40 is not enclosed in quotation marks.

ThisIsValid_02()

would return “ThisIsValid_02”

For a valid function name I came across: “[A-Za-z_][A-Za-z_0-9]*”
But I can’t for the life of me figure out how to match the rest.
I’ve been playing around on http://regexpal.com/ to try to get valid matches to all conditions, but to no avail 🙁

It would be nice if you kindly explained the regex too, so I can learn 🙂

Answer 1

Someone else has already given an answer that gives you a flat list of strings, but in the interest of strong typing and proper class structure, I’m going to provide a solution that encapsulates the data properly.

First, declare two classes:

public class ParamValue         // For a parameter and its value
{
    public string Parameter;
    public string Value;
}
public class FunctionInfo       // For a whole function with all its parameters
{
    public string FunctionName;
    public List<ParamValue> Values;
}

Then do the matching and populate a list of FunctionInfos:

(By the way, I’ve made some slight fixes to the regexes… it will now match identifiers correctly, and it will not include the double-quotes as part of the “value” of each parameter.)

Regex r = new Regex(@"(?<function>[\p{L}_]\w*?)\((?<inner>.*?)\)");
Regex inner = new Regex(@",?(?<param>.+?):""(?<value>[^""]*?)""");
string input = "_test0(a:\"lolololol\",b:\"2\") _test1(ghgasghe:\"asjkdgh\")";

var matches = new List<FunctionInfo>();

if (r.IsMatch(input))
{
    MatchCollection mc = r.Matches(input);
    foreach (Match match in mc)
    {
        var l = new List<ParamValue>();

        foreach (Match m in inner.Matches(match.Groups["inner"].Value))
            l.Add(new ParamValue
            {
                Parameter = m.Groups["param"].Value,
                Value = m.Groups["value"].Value
            });

        matches.Add(new FunctionInfo
        {
            FunctionName = match.Groups["function"].Value,
            Values = l
        });
    }
}

Then you can access the collection nicely with identifiers like FunctionName:

foreach (var match in matches)
{
    Console.WriteLine("{0}({1})", match.FunctionName,
        string.Join(", ", match.Values.Select(val =>
            string.Format("{0}: \"{1}\"", val.Parameter, val.Value))));
}