On Thu, May 20, 2010 at 11:53:09AM +1200, Richard O'Keefe wrote: > > On May 20, 2010, at 3:18 AM, Brent Yorgey wrote: > >> On Wed, May 19, 2010 at 04:27:14AM +0000, R J wrote: >>> >>> What are some simple functions that would naturally have the following >>> type signatures: >>> f :: (Integer -> Integer) -> Integer >> > The key point is the 'that would NATURALLY have', which I take > to mean "as a result of type inference without any forcibly > imposed type signatures".
Given that this is an exercise in Chapter 1, I kind of doubt this is really what it is supposed to mean. Are people reading chapter 1 really expected to understand the intricacies of type inference and the Num class? And to know about 'toInteger' and the fact that numeric constants are polymorphic? I really doubt it. I read the question much more simply, with "naturally" having a much more informal meaning than you suggest. I interpret the question as simply getting the reader some practice with basic higher-order types. I haven't read the Bird book though, so I could be wrong. -Brent _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
