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RE: [Caml-list] Turning off type-checking
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Date: | 2002-05-14 (08:20) |
From: | Alain Frisch <frisch@c...> |
Subject: | Re: [Caml-list] Turning off type-checking |
On Tue, 14 May 2002, Francois Pottier wrote: > The worst-case complexity is obtained by nesting `let' bindings > on the left side, i.e. > > let x1 = let x2 = let x3 = ... > > Do you generate such code, Markus? Mmm, I thought (misleaded by a teacher, of course) that the following would exhibit exponential behavior of type-inference: let f y z = (z y) y let f y = f (f y) let f y = f (f y) let f y = f (f y) let f y = f (f y) let f y = f (f y) (* ad libitum *) It seems that what takes time is occurence checking (disabled with -rectypes) and pretty-printing of types (because internally, there are many sharings), not type inference itself. For this (unatural) example, bad behaviour of occurence checking is visible (less than 0.04 seconds with -rectypes, and more than 10 minutes [I'm not patient enough to wait more] without -rectypes). -- Alain ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners