Webmention endpoint discovery in Haskell. Probably the best function ever written :-)

This is how I search for it in HTML.

listToMaybe $ unsafePerformIO $ runX $ htmlDoc //> hasAttrValue "rel" isWebmentionRel >>> getAttrValue "href"

Why unsafePerformIO? Because there’s no reason for HTML parsing to depend on IO, but they’ve implemented parsing strings as parsing files with the string protocol.