Re: [Caml-list] Lambda-Term (f x) (x f) translated to Ocaml?

[Oliver Bandel <oliver@first.in-berlin.de>]

On Tue, Mar 28, 2006 at 02:44:55AM +0200, yoann padioleau wrote:
> 
> > Hello,
> > 
> > I'm not firm in lambda calculus, what is the lambda-term
> > in the subject translated to OCaml?
> > 
> > Is this possible?
> 
> the ocaml interpreter dont want this definition
> 
> let g f x = (f x) (x f)

Oh, looks easy....  ( at least the definition on the left side ;-) )




> 
> and shout: 
>   this expression has type ('a -> 'b) -> 'c -> 'd but is here used with type 'a

OK, 
I tried this:


=====================================================================
first:~/Desktop oliver$ ocaml
        Objective Caml version 3.09.0

# let g f x = (f x) (x f) ;;
This expression has type ('a -> 'b) -> 'c -> 'd but is here used with type 'a
# ^D
first:~/Desktop oliver$ ocaml -rectypes
        Objective Caml version 3.09.0

# let g f x = (f x) (x f) ;;
val g : (('a -> 'c as 'b) -> 'c -> 'd as 'a) -> 'b -> 'd = <fun>
# 
=====================================================================

Well, looks complicated to me.

Any hints to this?

Ciao,
   Oliver