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[Caml-list] undocumented external ... = "%identity"
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Date: | 2003-11-03 (14:02) |
From: | Damien Doligez <damien.doligez@i...> |
Subject: | Re: [Caml-list] undocumented external ... = "%identity" |
On Saturday, November 1, 2003, at 09:22 AM, Stefano Zacchiroli wrote: > The fact that Obj.magic _implementation_ depends on the entire > implementation of the OCaml compiler and runtime, doesn't imply that > its > _interface_ does as well. Depends on what you mean by "interface". The _specification_ of Obj.magic depends on many implementation choices of the compiler and runtime. > If I'm using Obj.magic I'm supposed to know what I'm doing (the > examples > reported in the post you mentioned are significative here) and that I'm > sure that the type magic I'm doing are correct. In such a case the > correctness of those magics will change only when the assumption on > which their correction rely changes, for example a change in the type > system. ... or a change in the data representations used by the compiler and runtime. > Such major changes are usually backward compatibile, if not I suppose > the Obj.magic forward porting problem will be the minor problem > programmer will have with a new ocaml release ... Not true. We can make changes that break many uses of Obj.magic without changing the language or the type system. That's why Obj.magic is not documented. -- Damien ------------------- 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