puny_encode: Encode Unicode domain labels to ASCII Punycode (low-level)

In punycoder: Unicode and Punycode Domain Name Processing

Encode Unicode domain labels to ASCII Punycode (low-level)

Description

Converts Unicode domain names to their ASCII Punycode (⁠xn--⁠) representation: the raw RFC 3492 Bootstring transform wrapped in the RFC 5890/5891 A-label framing, plus letter-digit-hyphen and leading/trailing hyphen checks per label. DNS host length limits are intentionally not applied by this raw codec; use validate_domain() or host_normalize() when you need DNS host validation.

Usage

puny_encode(x, strict = getOption("punycoder.strict", TRUE))

Arguments

x	Character vector of Unicode domain names to encode
strict	Logical; whether to apply strict validation. Defaults to getOption("punycoder.strict", TRUE). In strict mode the raw codec enforces structural checks but not DNS host length limits.

Details

This is a low-level ASCII-Compatible Encoding helper, not an IDNA normalization API. It does not apply Unicode NFC, UTS #46 mapping, case folding, or Bidi/Joiner validation. To map a host name to its canonical comparison form under a UTS #46 profile (the IDNA surface of this package), use host_normalize().

Value

A character vector the same length as x, with each element containing the ASCII punycode-encoded domain name. Elements corresponding to NA inputs are NA_character_. In non-strict mode, domains that fail encoding are also returned as NA_character_.

See Also

puny_decode for the reverse operation, host_normalize for IDNA/UTS-46 host normalization, url_encode for full URL encoding.

Examples

# Basic encoding
puny_encode("caf\u00E9.com")
puny_encode("\u043C\u043E\u0441\u043A\u0432\u0430.\u0440\u0444")

# Vectorized encoding
domains <- c(
  "caf\u00E9.com",
  "\u043C\u043E\u0441\u043A\u0432\u0430.\u0440\u0444",
  "\u5317\u4EAC.\u4E2D\u56FD"
)
puny_encode(domains)

punycoder documentation built on July 20, 2026, 1:07 a.m.