Emre Tezel
Sun, 12 May 2002 19:19:40 -0400

Hi all,

I recently bought Simon Thompson's Haskell book. I have been doing the 
exercises while I read on. There are couple questions that I can not 
solve. Any help would be greatly appreciated.

I got stuck on this question in Chapter 10.

Define a function composeList which composes a list of functions into a 
single function. What is the type of composeList?

I naively tried the following but the hugs compiler complained about the 
inferred type not being generic enough.

composeList :: [(a -> b)] -> (c -> b)
composeList [] = id
composeList (x:xs) = x . (composeList xs)


composeList :: [(a -> b)] -> (c -> b)
composeList (x:xs) = x . (composeList xs)

ERROR "Chapter10.hs":6 - Inferred type is not general enough
*** Expression    : composeList
*** Expected type : [a -> b] -> c -> b
*** Inferred type : [a -> a] -> b -> a

Anybody can solve this?