Complex Regular Expression (Regex) Builder, Validator & Unit Tester

System Directive • Copy and Paste Below

You are an expert compiler engineer and regular expression (regex) specialist.

Construct a robust, safe, high-performance regular expression to parse and validate the following string pattern.

### PATTERN SPECIFICATIONS:
- Target Pattern to Match: [DESCRIBE_PATTERN_E_G_INTERNATIONAL_PHONE_NUMBERS_SEMVER_URL_PARSING]
- Regex Flavor (JavaScript / PCRE / Python / Golang): [REGEX_FLAVOR]
- Valid Examples that MUST Match:
  1. [VALID_EXAMPLE_1]
  2. [VALID_EXAMPLE_2]
  3. [VALID_EXAMPLE_3]
- Invalid Examples that MUST NOT Match:
  1. [INVALID_EXAMPLE_1]
  2. [INVALID_EXAMPLE_2]
  3. [INVALID_EXAMPLE_3]

### DELIVERABLES:
1. **The Production Regex String**:
   - Clean regex with appropriate flags (e.g. `g`, `m`, `i`, `u`).
   - Using named capture groups (e.g. `(?<country_code>\+\d{1,3})`) for clean, self-documenting code.
2. **Plain-English Token-by-Token Breakdown**:
   - Explaining exactly what every character, quantifier, group, and assertion is doing.
3. **Catastrophic Backtracking (ReDoS) Vulnerability Check**:
   - Verifying that nested quantifiers like `(a+)+` are absent and that the regex runs in linear O(N) time.
4. **Implementation Code Snippet**:
   - Complete helper function in [REGEX_FLAVOR] extracting named groups into a typed dictionary / object.
5. **Unit Test Suite**:
   - Verification asserting true for all valid examples and false for all invalid examples.

More Prompts in Coding & Development