Regular Expressions

Features

• RegexCollection: source-generated compiled regex methods for common patterns — email address, contains a digit, contains a lowercase letter, contains an uppercase letter, contains all three (digit + lowercase + uppercase).
• RegexExtensions: Remove extension method on Regex that strips all pattern matches from a string.

Every pattern is ASCII only, anchored with \z where it is anchored at all, and compiled with a MatchTimeoutMilliseconds ceiling so no input can make a match run unbounded. For faster character class checks, results that name which requirement failed, or email normalization, see Text.

Class Diagram

classDiagram
    namespace RegularExpressions {
        class RegexCollection {
            <<static>>
            +const int MatchTimeoutMilliseconds
            +const string EmailPattern
            +const string HasNumberPattern
            +const string HasLowerCharPattern
            +const string HasUpperCharPattern
            +const string HasNumberLowerAndUpperCharPattern
            +Regex Email()
            +Regex HasNumber()
            +Regex HasLowerChar()
            +Regex HasUpperChar()
            +Regex HasNumberLowerAndUpperChar()
        }
        class RegexExtensions {
            <<static>>
            +string Remove(Regex regex, string @string)
        }
    }
    RegexExtensions ..> RegexCollection : extends

Usage

Matching

using ArturRios.Util.RegularExpressions;

bool isEmail  = RegexCollection.Email().IsMatch("john@doe.com"); // true
bool isEmail2 = RegexCollection.Email().IsMatch("not-an-email"); // false

bool hasDigit = RegexCollection.HasNumber().IsMatch("abc123");   // true
bool hasLower = RegexCollection.HasLowerChar().IsMatch("Hello"); // true
bool hasUpper = RegexCollection.HasUpperChar().IsMatch("Hello"); // true

// Check password complexity in a single call
bool isComplex = RegexCollection.HasNumberLowerAndUpperChar().IsMatch("Password1"); // true

EmailPattern accepts a single address only. Display names, comments, groups and comma-separated lists are rejected by design, as are non-ASCII local parts and unbracketed IP hosts — an address literal must be written user@[192.168.1.1]. To accept an internationalized domain, normalize the address first with EmailAddress.TryNormalize.

Removing matches

using ArturRios.Util.RegularExpressions;

// Strip all digits from a string
string lettersOnly = RegexCollection.HasNumber().Remove("abc123def456"); // "abcdef"

// Strip all lowercase letters
string noLower = RegexCollection.HasLowerChar().Remove("Hello World"); // "H W"