using-generated-regex

# Using GeneratedRegex (Source Generator) Use `GeneratedRegexAttribute` for compile-time regex generation instead of runtime `new Regex()`. ## Why GeneratedRegex? | Aspect | Runtime Regex | GeneratedRegex | |--------|--------------|----------------| | Compilation | Runtime | Compile-time | | Performance | Slower first match | Pre-compiled, faster | | AOT Support | Limited | Full support | | Memory | Allocates at runtime | No runtime allocation | | .NET Version | All | .NET 7+ | --- ## Basic Pattern ```csharp public partial class EmailValidator { [GeneratedRegex(@"^[\w\.-]+@[\w\.-]+\.\w+$", RegexOptions.IgnoreCase)] private static partial Regex EmailPattern(); public bool IsValidEmail(string email) { return EmailPattern().IsMatch(email); } } ``` **Requirements:** - Class must be `partial` - Method must be `static partial` returning `Regex` - .NET 7 or later --- ## Common Patterns ### Email Validation ```csharp public partial class ValidationPatterns { [GeneratedRegex(@"^[\w\.-]+@[\w\.-]+\.\w+$", RegexOptions.IgnoreCase)] public static partial Regex Email(); } ``` ### Phone Number ```csharp [GeneratedRegex(@"^\d{3}-\d{3,4}-\d{4}$")] public static partial Regex PhoneNumber(); ``` ### URL Pattern ```csharp [GeneratedRegex(@"^https?://[\w\.-]+(?:/[\w\.-]*)*$", RegexOptions.IgnoreCase)] public static partial Regex Url(); ``` ### Whitespace Normalization ```csharp [GeneratedRegex(@"\s+")] private static partial Regex WhitespacePa...