Re: Another Newbie question :)

Keith is entirely correct.

You can see this from the definition of foldr:

foldr :: (a -> b -> b) -> b -> [a] -> b foldr f z [] = z foldr f z (x:xs) = f x (foldr f z xs)

where clearly every [] is replaced by z and every : by f.

I had heard this before when I was first beginning and didn't really find it "clear" :). I think if you write foldr with f in infix notation it's a bit more clear:

foldr f z [] = z foldr f z (x:xs) = x `f` foldr f z xs

or even write the second line as

foldr f z (x:xs) = x `f` xs' where xs' = foldr f z xs

I think in this case it's a bit more clear how "f" is replacing the ":". - Hal