Regular expression for valid signature names

I having the following regexp for validating the function name:

([a-zA-Z]\w+)[^\w]

This regular expression is capable of avoiding special characters except underscore but if we put special characters in the beginning then t开发者_如何学JAVAhis expression can't validate.

So can you make it work little better?

thanks in adv

---

You need to match from the beginning to the end of the whole function name:

^([a-zA-Z]\w+)[^\w]$

---

Following the C# language specification:

http://msdn.microsoft.com/en-us/library/aa664670(VS.71).aspx

The following regex will handle special cases of '_' and '@', plus validate non ASCII letters i.e. validates unicode identifiers.

[Test]
public void ValidateIdentifiers()
{
  Regex regex = new Regex(
  @"^@?_*[\p{Ll}\p{Lu}\p{Lt}\p{Lo}\p{Nd}\p{Nl}\p{Mn}\p{Mc}\p{Cf}\p{Pc}\p{Lm}]*$");

  Assert.That(regex.IsMatch("Bling"),   Is.True);
  Assert.That(regex.IsMatch("@_Bling"), Is.True);
  Assert.That(regex.IsMatch("_Bling"), Is.True);
  Assert.That(regex.IsMatch("__Bling"), Is.True);
  Assert.That(regex.IsMatch("_Bling_Bling"), Is.True);
  Assert.That(regex.IsMatch("السياحى"), Is.True);
  Assert.That(regex.IsMatch("_@Bling"), Is.False);
}

---

Right now the expression is saying: one letter followed by one or more letter/numbers/underscores, followed by a non-word character. So by design, the fact that it won't validate if you start with a special character is correct.

If you want to allow for the _ as the first letter, change to:

(\w+)[^\w]