DrawboardLtd/Nunycode

Punycode for .NET derived from https://mths.be/punycode

Nunycode

Nunycode is a .NET Standard library that implements Punycode conversion in compliance to RFC 3492 and RFC 5891.

It was ported from punycode.js, which was bundled with Node.js from v0.6.2+ until its soft-deprecation in v7.

API

Punycode.Decode

Converts a Punycode string of ASCII symbols to a string of Unicode symbols.

// decode domain name parts
Console.WriteLine(Punycode.Decode("maana-pta")); // "mañana"
Console.WriteLine(Punycode.Decode("--dqo34k"));  // "☃-⌘"

Punycode.Encode

Converts a string of Unicode symbols to a Punycode string of ASCII symbols.

// encode domain name parts
Console.WriteLine(Punycode.Encode("mañana")); // "maana-pta"
Console.WriteLine(Punycode.Encode("☃-⌘"));    // "--dqo34k"

Punycode.ToUnicode

Converts a Punycode string representing a domain name or an e-mail address to Unicode. Only the Punycoded parts of the input will be converted, i.e. it doesn't matter if you call it on a string that has already been converted to Unicode.

// decode domain names
Console.WriteLine(Punycode.ToUnicode("xn--maana-pta.com"));
// → "mañana.com"
Console.WriteLine(Punycode.ToUnicode("xn----dqo34k.com"));
// → "☃-⌘.com"

// decode email addresses
Console.WriteLine(Punycode.ToUnicode("джумла@xn--p-8sbkgc5ag7bhce.xn--ba-lmcq"));
// → "джумла@джpумлатест.bрфa"

Punycode.ToASCII

Converts a lowercased Unicode string representing a domain name or an e-mail address to Punycode. Only the non-ASCII parts of the input will be converted, i.e. it doesn't matter if you call it with a domain that's already in ASCII.

// encode domain names
Console.WriteLine(Punycode.ToAscii("mañana.com"));
// → "xn--maana-pta.com"
Console.WriteLine(Punycode.ToAscii("☃-⌘.com"));
// → "xn----dqo34k.com"

// encode email addresses
Console.WriteLine(Punycode.ToAscii("джумла@джpумлатест.bрфa"));
// → "джумла@xn--p-8sbkgc5ag7bhce.xn--ba-lmcq"

Ucs2.Decode

Creates an array containing the numeric code point values of each Unicode symbol in the string. While .NET uses UCS-2 internally, this function will convert a pair of surrogate halves (each of which UCS-2 exposes as separate characters) into a single code point, matching UTF-16.

Console.WriteLine(Ucs2.Decode("abc"));
// → [97, 98, 99]
// → [0x61, 0x62, 0x63]
// surrogate pair for U+1D306 TETRAGRAM FOR CENTRE:
Console.WriteLine(Ucs2.Decode("\uD834\uDF06"));;
// → [119558]
// → [0x1D306]

Ucs2.Encode

Creates a string based on an array of numeric code point values.

Console.WriteLine(Ucs2.Encode(0x61, 0x62, 0x63));
// → "abc"
Console.WriteLine(Ucs2.Encode(0x1D306));
// → "\uD834\uDF06"