HKID Generator & Validator

A Rust library for generating and validating Hong Kong Identity Card (HKID) numbers, supporting all official and custom prefixes, with correct check digit calculation.

References

The implementation in this library is based on the following public resources:

• HKID Check Digit Validation

  • Validation Rules - Hong Kong (SAP Help Portal)

• HKID Symbol and Prefix Descriptions

  • Hong Kong identity card - Wikipedia

This ensures that the check digit calculation and the interpretation of HKID symbols and prefixes are consistent with established and publicly recognized standards.

Features

• Parse HKID symbols and prefixes
• Generate valid HKIDs (with correct check digit)
• Validate HKID numbers (including check digit computation)
• Support for both known and unknown HKID prefixes

Installation

Add this to your Cargo.toml:

[dependencies]
hkid_ops = "0.2.2"

Usage

use hkid_ops::hkid_ops::HKIDOps;

fn main() {
  let hkid_ops = HKIDOps {};

  // Generate a random HKID with a known prefix
  let hkid = hkid_ops.generate_hkid(None, true).unwrap();
  println!("Random valid HKID: {}", hkid);

  // Generate with a specific prefix
  let hkid_a = hkid_ops.generate_hkid(Some("A"), true).unwrap();
  println!("HKID with prefix A: {}", hkid_a);

  // Generate with a custom (unknown) prefix
  let hkid_custom = hkid_ops.generate_hkid(Some("ZZ"), false).unwrap();
  println!("HKID with custom prefix: {}", hkid_custom);

  // Validate an HKID
  match hkid_ops.validate_hkid(&hkid_a, true) {
    Ok(valid) => println!("Is HKID valid? {}", valid),
    Err(e) => println!("Validation error: {}", e),
  }
}

HKID Generation Logic

• Known Prefix:
  When must_exist_in_enum is true, only standard HKID prefixes are allowed.
• Random Prefix:
  When prefix is None:
  • If must_exist_in_enum is true, a random known prefix is chosen.
  • If must_exist_in_enum is false, a random 1- or 2-letter uppercase prefix is generated.
• Unknown/Custom Prefix:
  Allowed only if must_exist_in_enum is false.

License

This project is licensed under the MIT License.

You are free to use, modify, and distribute this software under the terms of the MIT License. For detailed terms and conditions, please refer to the LICENSE file in this repository.