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Subject: forbidden construct as right hand side of "let rec"
From: Mathias Kende <mathias@kende.fr>
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Date: Fri, 23 Oct 2009 00:22:01 +0200
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X-Spam: no; 0.00; compiler:01 ocaml:01 rec':01 recursive:01 ocaml:01 mathias:98 mathias:98 rec:01 rec:01 right-hand:01 define:02 expression:02 parameter:02 construct:02 let:03 

Hello list,

I need to write something like this :

	let f f i = if i = 0 then 1 else i * f (i - 1)
	let rec g = f g

Of course the compiler won't let me write it (even if the OCaml type
system is happy):
	"This kind of expression is not allowed as right-hand side of `let rec'"

But as the function parameter of function f is used only for a recursive
call I believe that the function I try the define is at least "morally"
correct.

Is there a way to express this sort of construction in OCaml ? My aim is
to be able to have some things equivalent to:
	let rec g = f g
and
	let rec h = t (f h)
where t is some transformation over the function (conserving its type),
and still writing the code for f only once.

Regards,

Mathias