From: skaller <skaller@users.sourceforge.net>
To: caml-list@inria.fr
Subject: tail rec
Date: Sat, 19 May 2007 12:56:05 +1000 [thread overview]
Message-ID: <1179543365.26755.33.camel@rosella.wigram> (raw)
I have a silly idea. Introduce a new construction:
let tailrec f ..
This is the same as let rec except it checks every direct call to f
is in tail position (and bombs out the compiler if not).
[Maybe this can be done with camlp4, though I think it might
be hard?]
I think this could be useful for newbies learning functional
programming, and perhaps even experts looking for performance
issues.
If a let closure of f is made, a warning is issued, eg:
let tailrec f x =
let g x = f x in (* WARNING *)
1 + g (x - 1) (* not tail, but not explicit call of f *)
The annotation does NOT prove a function is tail rec,
but if the compiler bombs, it proves the function is
not tail rec.
Comments?
--
John Skaller <skaller at users dot sf dot net>
Felix, successor to C++: http://felix.sf.net
next reply other threads:[~2007-05-19 2:56 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-19 2:56 skaller [this message]
2007-05-19 5:00 ` [Caml-list] " Erik de Castro Lopo
2007-05-19 5:28 ` Basile STARYNKEVITCH
2007-05-19 12:58 ` skaller
2007-05-19 20:19 ` Jonathan Bryant
2007-05-19 21:55 ` Erik de Castro Lopo
2007-05-19 22:13 ` skaller
2007-05-19 14:28 ` Oliver Bandel
2007-05-19 14:46 ` Oliver Bandel
2007-05-19 16:06 ` skaller
2007-05-21 12:57 ` Brian Hurt
2007-05-21 13:04 ` Robert Fischer
2007-05-21 13:21 ` Basile STARYNKEVITCH
2007-05-21 13:30 ` Robert Fischer
2007-05-21 14:00 ` Brian Hurt
2007-05-21 13:47 ` Daniel Bünzli
2007-05-21 14:24 ` Christopher L Conway
2007-05-21 14:36 ` Jon Harrop
2007-05-21 14:49 ` Richard Jones
2007-05-21 14:42 ` ocaml faq (was [Caml-list] tail rec) Daniel Bünzli
2007-05-21 15:09 ` Christopher L Conway
2007-05-21 15:17 ` Robert Fischer
2007-05-21 15:27 ` Daniel Bünzli
2007-05-21 16:23 ` Richard Jones
2007-05-21 16:59 ` Robert Fischer
2007-05-21 16:26 ` Richard Jones
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