dsl1.cs

Pattern phoneNumber = Pattern.With
  .AtBeginning.Choice.Either(
    Pattern.With.Literal("02"),
    Pattern.With.Literal("03"),
    Pattern.With.Literal("04"),
    Pattern.With.Literal("08"),
    Pattern.With.Literal("09"),
    Pattern.With.Literal("072"),
    Pattern.With.Literal("073"),
    Pattern.With.Literal("074"),
    Pattern.With.Literal("076"),
    Pattern.With.Literal("077"),
    Pattern.With.Literal("050"),
    Pattern.With.Literal("052"),
    Pattern.With.Literal("054")
    )
  .Digit.Repeat.InRange(6,7).AtEnd;

dsl2.cs

Pattern phoneNumber = Pattern.With
  .AtBeginning.Choice.Either(
    Pattern.With.Literal("02"),
    Pattern.With.Literal("03"),
    Pattern.With.Literal("04"),
    Pattern.With.Literal("08"),
    Pattern.With.Literal("09"),
    Pattern.With.Literal("072"),
    Pattern.With.Literal("073"),
    Pattern.With.Literal("074"),
    Pattern.With.Literal("076"),
    Pattern.With.Literal("077"),
    Pattern.With.Literal("050"),
    Pattern.With.Literal("052"),
    Pattern.With.Literal("054")
    )
  .WhiteSpace.Repeat.Optional
  .Literal("-").Repeat.Optional
  .WhiteSpace.Repeat.Optional
  .Digit.Repeat.InRange(6,7).AtEnd;

email-regex.txt

^((?>[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+\x20*|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*"\x20*)*(?<angle><))?((?!\.)(?>\.?[a-zA-Z\d!#$%&'*+\-/=?^_`{|}~]+)+|"((?=[\x01-\x7f])[^"\\]|\\[\x01-\x7f])*")@(((?!-)[a-zA-Z\d\-]+(?<!-)\.)+[a-zA-Z]{2,}|\[(((?(?<!\[)\.)(25[0-5]|2[0-4]\d|[01]?\d?\d)){4}|[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])[^\\\[\]]|\\[\x01-\x7f])+)\])(?(angle)>)$

phone-number-example.txt

03 6382020

phone-number-regex.txt

^(([0]([2|3|4|8|9|72|73|74|76|77])))[2-9]\d{6,7}$

sharp-kit-quote.txt

When you work with SharpKit, you write C# instead of JavaScript

two-probs-quote.txt

Some people, when confronted with a problem, think "I know, I'll use regular expressions."
Now they have two problems.

validator1.cs

namespace Electron.Validation
{
  public static class CharExt
  {
    public static bool IsDigit(this char c)
    {
      return c >= '0' && c <= '9';
    }
  }
   
  public class PhoneNumber
  {
    public static bool IsValid(string s)
    {
      if (null == s)
        return false;
 
      var validPrefixes = new[] {
                    "02", 
                    "03", 
                    "04", 
                    "08", 
                    "09", 
                    "072", 
                    "073", 
                    "074", 
                    "076", 
                    "077", 
                    "050", 
                    "052", 
                    "054"
                    };
      int prefixLength = 0;
      var foundMatchingPrefix = false;
      foreach (var validPrefix in validPrefixes)
        if (s.StartsWith(validPrefix))
        {
          prefixLength = validPrefix.Length;
          foundMatchingPrefix = true;
          break;
        }
 
      if (!foundMatchingPrefix)
        return false;
 
      // remaining length should be between 6 and 7
      var remainingLength = s.Length - prefixLength;
      if (!((6 == remainingLength) || (7 == remainingLength)))
        return false;
 
      // check the rest of the string to be digits
      for (int i = prefixLength; i < s.Length; i++)
        if (!s[i].IsDigit())
          return false;
       
      return true;
    }
  }
}

validator2.cs

public class PhoneNumber
{
  public static bool IsValid(string s)
  {
    if (null == s)
      return false;
 
    var validPrefixes = new[] { 
                  "02", 
                  "03", 
                  "04", 
                  "08", 
                  "09", 
                  "072", 
                  "073", 
                  "074", 
                  "076", 
                  "077", 
                  "050", 
                  "052", 
                  "054"
                  };
    int prefixLength = 0;
    var foundMatchingPrefix = false;
    foreach (var validPrefix in validPrefixes)
      if (s.StartsWith(validPrefix))
      {
        prefixLength = validPrefix.Length;
        foundMatchingPrefix = true;
        break;
      }
 
    if (!foundMatchingPrefix)
      return false;
 
    if (s.Length == prefixLength)
      return false;
 
    int nextDigitIndex;
    if (s[prefixLength] == ' ')
      nextDigitIndex = prefixLength + 1;
    else
      nextDigitIndex = prefixLength;
 
    // remaining length should be between 6 and 7
    var remainingLength = s.Length - nextDigitIndex;
    if (!((6 == remainingLength) || (7 == remainingLength)))
      return false;
 
    // check the rest of the string to be digits
    for (int i = nextDigitIndex; i < s.Length; i++)
      if (!s[i].IsDigit())
        return false;
       
    return true;
  }
}