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From: Mathias Kende <mathias@kende.fr>
To: caml-list@yquem.inria.fr
Subject: forbidden construct as right hand side of "let rec"
Date: Fri, 23 Oct 2009 00:22:01 +0200	[thread overview]
Message-ID: <1256250121.4178.37.camel@MATHIAS-ENS> (raw)

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




             reply	other threads:[~2009-10-22 22:22 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-22 22:22 Mathias Kende [this message]
2009-10-22 22:34 ` [Caml-list] " Stéphane Glondu
2009-10-22 23:10   ` Lukasz Stafiniak
2009-10-23 15:35     ` Damien Guichard
2009-10-23 16:14       ` Marc de Falco
2009-10-23 17:51         ` blue storm
2009-10-25 14:11   ` Mathias Kende
2009-10-25 15:03     ` Stéphane Glondu
2009-10-28 16:52 ` Xavier Leroy
2009-10-28 22:44   ` Lukasz Stafiniak

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