On 17/02/2008, Steve Lihn
While I am reading TypeCompose module, I am having trouble finding where ~> comes from? (And its son ~~> and grandson ~~~>, etc.) This is my immediate question. Help is appreciated.
(~>) is typically an infix type variable. If it were a constructor, it would have to start with a colon. So it doesn't have a definition as such, you can think of it as any type constructor with at least two type parameters. I think that would explain why you were having such trouble searching for it! Generally, though, if you want to know where something is defined, you can use ghci's :info command, and it should tell you the file and line in which it's defined, as well as its type (if it's a value) and its fixity (if it's an infix operator). You can then load up whatever documentation or source code is available for that module. Of course, in this case, it would report (correctly) that (~>) is not in scope. Usually, packages on Hackage have whatever documentation is available linked directly from their pages on Hackage. hope this helps! - Cale