ocaml programming

[xx04201987xx]

I'm doing my programming assignment and I'm stuck on this part.
so this function is supposed to behave like this

# pipe [] 3;;
- : int = 3
# pipe [(fun x-> 2*x);(fun x -> x + 3)] 3 ;;
- : int = 9
# pipe [(fun x -> x + 3);(fun x-> 2*x)] 3;;
- : int = 12

if the list contains functions it will execute them all in order then return int
if there is no function in the list it returns the initial value.

and this is the skeleton given to us and we can edit .... part of the code

let pipe fs =
let f b x = ....... in
let base = ....... in
List.fold_left f base fs

what I tried to do is...
let pipe fs =
let f b x = x b in
let base = fun y -> y in
List.fold_left f base fs

but this had type error.
when I run it on ocaml command line i get
# pipe [(fun x-> 2*x);(fun x -> x + 3)] 3 ;;
This expression has type 'a -> 'a but is here used with type int

I can't figure out what to do so I pass in int for the parameter...
any feed back will be very helpful for me.
thanks in advance.

 

[dinkumthinkum]

"let f b x = x b" is wrong. Think about it. You want "f" to return a function which takes a value, calls x with it, then takes the result of that, and calls b with it. That's function composition.