> > ===========================================
> > first:~ oliver$ ocaml
> >         Objective Caml version 3.09.2
> > 
> > # let floatingpoint_id (x:float) = x;;
> > val floatingpoint_id : float -> float = <fun>
> > # floatingpoint_id 42;;
> > This expression has type int but is here used with type float
> > # 
> > ===========================================
> 
> float_of_string doesn't use the ocaml type system ;-) Don't know 
> about 
> impl details, but it's basically like atof (or whatever it's called) 
> in 
> standard C libs. The two are completely separate.

Oops, I should clarify: float_of_string doesn't use the ocaml lexing 
tools that are used in the toplevel, and the compilers themselves. 
That's why it parses integers.

Jonathan