puny_decode: Decode ASCII Punycode to Unicode domain labels (low-level)

In punycoder: Unicode and Punycode Domain Name Processing

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

Description

Converts ASCII Punycode (⁠xn--⁠) domain names back to their Unicode representation. This is the inverse of puny_encode() and is the raw RFC 3492 transform with A-label framing checks. 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_decode(x, strict = getOption("punycoder.strict", TRUE))

Arguments

x	Character vector of ASCII punycode domains to decode
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

Like puny_encode(), this is a low-level ASCII-Compatible Encoding helper, not an IDNA normalization API: it does not apply UTS #46 mapping or NFC. For IDNA/UTS-46 host normalization, see host_normalize().

Value

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

See Also

puny_encode for the reverse operation, host_normalize for IDNA/UTS-46 host normalization, url_decode for full URL decoding.

Examples

# Basic decoding
puny_decode("xn--caf-dma.com")
puny_decode("xn--80adxhks.xn--p1ai")

# Vectorized decoding
ascii_domains <- c("xn--caf-dma.com", "xn--80adxhks.xn--p1ai")
puny_decode(ascii_domains)

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