title: How does Langage.Haskell.TH.report work?
body: <p>Unfortunately, many Template Haskell functions have absolutely no documentation at all. One such function is <code>report</code>. It takes a <code>Bool</code> and a <code>String</code>, and produces a compilation error with the specified string as the error message. Does anybody have any clue what the hell the <code>Bool</code> is for? As best as I can tell, either value does exactly the same thing...</p>