From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,29fe9a340e0d180d X-Google-Attributes: gid103376,public From: Brian Rogoff Subject: Re: Depending on passing mechanism Date: 1997/10/16 Message-ID: #1/1 X-Deja-AN: 281057719 References: <622b4t$nhe$1@gonzo.sun3.iaf.nl> X-Trace: 877033568 14587 bpr 206.184.139.132 Newsgroups: comp.lang.ada Date: 1997-10-16T00:00:00+00:00 List-Id: On Wed, 15 Oct 1997, Henry Baker wrote: > In article <622b4t$nhe$1@gonzo.sun3.iaf.nl>, Geert Bosch > wrote: > > ... about non-determinism and Ada parameter passing ... > > > > Do you have a proposal to remove the non-determinism without affecting > > performance and flexibility too much? I think many readers in this > > group might be interested in such ideas, at least I am. > > > > Regards, > > Geert > > 3. Add a new concept to your language: 'linear'/'unique' types. These > objects are guaranteed to be singly referenced because this is enforced > by the type system. Poof! No aliasing! This concept was pioneered by > NIL/Hermes, and has recently been incorporated into some logical (prolog-like) > languages and some functional languages ('Clean' from KU Leaven). There is a > large and growing body of mathematics called 'linear logic' that puts linear > types on a firm theoretical foundation. I remember reading something about NIL a long time ago (this is from Bell Labs, right?) and their notion of "typestates", which I think what I think you are talking about, and I thought that they stated that there was a fairly significant performance overhead in their use, and hence they wouldn't be really suitable in the role that you are proposing for them in Ada. Anyone have different information? -- Brian