IDNA - International Domain Name functions for Common Lisp.

Usage (unicode -> punycode only at the moment):

Loading:

    (asdf:load-system :idna)

Encoding strings as IDNA:

    (idna:to-ascii "中央大学.tw")
    ;; => "xn--fiq80yua78t.tw"

    (idna:to-ascii "müller.example.com")
    ;; => "xn--mller-kva.example.com"

Decoding strings from IDNA notation to unicode text:

    (idna:to-unicode "xn--fiq80yua78t.tw")
    ;; => "中央大学.tw"

Known bugs

The functions punycode-encode accept a :preserve-case keyword argument that currently doesn't work: punycode-encode returns wrong results, and punycode-decode doesn't implement it at all.