Hello,

 

I'm new at haskell and I have the following question:

 

let's say I type the following:

 

function = foldr until

 

Now my first question is what is the type of this function? Well let's see what the type of until and foldr is:

 

until :: (a -> Bool) -> (a -> a) -> a -> a

foldr :: (a -> b -> b) -> b -> [a] -> b

 

So I would be thinking: we fill until in the position of (a -> b -> b) so, a correspond with (a -> Bool) and b correspond with (a -> a) and b correspond with a. Hmm a small problem, I think we can divide that as follows: b1 corresponds with (a -> a) and b2 corresponds with a. So I get:

 

foldr until :: b1 -> [a] -> b2

foldr until :: (a -> a) -> [a -> Bool] -> a

 

Is this a correct way of thinking or am I wrong?

 

And another question is: can someone give me an example how this can be executed? All my code that I tried to execute resulted in errors with "foldr until".

 

Thanks!