NEWS.md

In punycoder: Unicode and Punycode Domain Name Processing

punycoder 1.1.0

New Features

• host_normalize() converts hostnames to their canonical comparison form under a pinned UTS-46 profile (non-transitional, UseSTD3ASCIIRules, CheckHyphens, CheckBidi, CheckJoiners, NFC, DNS length verification), returning lowercase ASCII A-labels or NA for invalid input. The mapping/NFC/validation pipeline is implemented in-tree over vendored Unicode 16.0.0 data, so behavior is independent of whether libidn2 is present.
• normalization_profile_info() exposes the machine-readable profile identity (profile, unicode_version, and the profile parameters) for downstream reproducibility keys.

punycoder 1.0.0

First CRAN release.

Bug Fixes

• puny_decode() (and the URL/domain decoders) now bound label length in both strict and non-strict mode. A crafted oversized xn-- label previously drove the fallback decoder into quadratic time with unbounded allocation; oversized labels are now rejected promptly (error in strict mode, NA in non-strict).

New Features

• Strict decoding now enforces RFC 5891 canonical A-label form: a decoded label must re-encode to itself. Non-canonical encodings (e.g. uppercase payloads) are rejected in strict mode while non-strict decoding stays lenient.
• Initial release of punycoder package
• Core punycode encoding and decoding functions (puny_encode(), puny_decode())
• URL-aware processing functions (url_encode(), url_decode(), parse_url())
• Domain validation and utility functions (is_punycode(), is_idn(), validate_domain())
• Comprehensive test suite with RFC 3492 compliance testing
• High-performance C++ backend with Rcpp
• Vectorized operations for bulk processing
• Robust error handling and validation
• Complete documentation with vignettes

Package Structure

• CRAN-compliant package structure
• MIT license
• Comprehensive test coverage
• Performance optimizations
• Cross-platform compatibility (Windows, macOS, Linux)

Technical Implementation

• C++ backend using Rcpp for performance
• Placeholder implementation ready for libidn2 integration
• RFC 3492 compliance framework
• Extensive input validation
• Memory-efficient vectorized operations

Documentation

• Complete function documentation with examples
• Introductory vignette
• README with quick start guide
• Test vectors from RFC 3492 specification

Future Roadmap

• Integration with GNU libidn2 for production punycode implementation
• Performance optimizations
• Additional URL manipulation utilities
• Integration examples with popular R packages

punycoder documentation built on June 16, 2026, 9:07 a.m.