From: Robert A Duff <bobduff@world.std.com>
Subject: Re: Compile time executed functions
Date: Mon, 2 Apr 2001 13:40:22 GMT
Date: 2001-04-02T13:40:22+00:00 [thread overview]
Message-ID: <wcczodzctdl.fsf@world.std.com> (raw)
In-Reply-To: DS_x6.695$UY5.185094242@newssvr16.news.prodigy.com
"Ken Garlington" <Ken.Garlington@computer.org> writes:
> Which is exactly the point - there doesn't seem to be a true "compile time"
> function with respect to either language, only optimization techniques that
> are applied to various degree in *instances* of the language.
Well, I wouldn't call the C++ template case an "optimization". To me,
and optimization is when the compiler goes to extra trouble in the hopes
of generating more efficient code. "Extra trouble" = more trouble than
the simplest compilation technique anybody can imagine. If a compiler
evaluates an Ada function at compile time, that's clearly an
optimization. But a C++ compiler would have to go to extra trouble
*not* to evaluate templates at compile time -- so I don't call it an
optimization to evaluate them at compile time. In fact, I'll bet that
100% of all C++ compilers that now exist, or that ever exist, are
capable of evaluating the example (the factorial template someone
posted) at compile time.
>... Note that it
> could be possible for a language to define required optimizations -- Erlang,
> for example, appears to do so with tail recursion -- but asking for Ada to
> provide the "same guarantees" as C++ in this area is vacuously true, AFAIK.
Formally speaking, that's true.
>...If your program was
> depending upon not being surprised, this would be a Bad Thing -- thus, it's
> always a good idea IMHO not to depend upon such "sanity".
It's unavoidable. All programs depend on various "sanity" aspects of
compilers -- aspects that are not formally defined in the language
definition.
- Bob
next prev parent reply other threads:[~2001-04-02 13:40 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-03-27 7:10 Compile time executed functions Mats Karlssohn
2001-03-27 13:30 ` Ken Garlington
2001-03-28 7:08 ` Mats Karlssohn
2001-03-28 19:07 ` Phaedrus
2001-03-29 7:41 ` Mats Karlssohn
2001-03-29 5:02 ` Ken Garlington
2001-03-29 7:58 ` Mats Karlssohn
2001-03-29 14:28 ` Ken Garlington
2001-03-29 14:48 ` Ted Dennison
2001-04-04 7:52 ` Mats Karlssohn
2001-04-04 14:05 ` Ted Dennison
2001-04-05 6:30 ` Mats Karlssohn
2001-03-29 19:48 ` Simon Wright
2001-03-31 19:30 ` Ken Garlington
2001-04-04 7:53 ` Mats Karlssohn
2001-03-30 10:41 ` Jean-Marc Bourguet
2001-03-30 16:13 ` Ken Garlington
2001-03-30 16:47 ` Jean-Marc Bourguet
2001-03-30 18:54 ` Stephen Leake
2001-04-01 8:42 ` Jean-Marc Bourguet
2001-03-31 19:30 ` Ken Garlington
2001-04-01 8:59 ` Jean-Marc Bourguet
2001-04-01 18:22 ` Ken Garlington
2001-04-02 9:30 ` Jean-Marc Bourguet
2001-04-02 12:42 ` Robert A Duff
2001-04-02 14:16 ` Jean-Marc Bourguet
2001-04-03 0:33 ` Pat Rogers
2001-04-02 13:09 ` Ken Garlington
2001-04-02 13:40 ` Robert A Duff [this message]
2001-04-02 23:29 ` Ken Garlington
2001-04-13 23:11 ` Robert A Duff
2001-04-02 14:32 ` Jean-Marc Bourguet
2001-04-04 7:59 ` Mats Karlssohn
2001-04-04 7:47 ` Mats Karlssohn
2001-04-06 0:33 ` Ken Garlington
2001-04-09 12:21 ` Mats Karlssohn
2001-04-13 15:51 ` Tucker Taft
2001-03-27 14:39 ` Ted Dennison
2001-03-27 16:40 ` Mark Biggar
2001-03-27 18:14 ` Florian Weimer
2001-03-27 18:15 ` Florian Weimer
2001-03-27 18:57 ` Ted Dennison
2001-03-27 19:22 ` Florian Weimer
2001-03-27 20:23 ` Ted Dennison
2001-03-27 22:15 ` Florian Weimer
2001-03-27 23:30 ` Georg Bauhaus
2001-03-28 9:54 ` Florian Weimer
2001-03-28 15:20 ` Ted Dennison
2001-03-28 16:12 ` David C. Hoos, Sr.
2001-03-28 21:15 ` Robert A Duff
2001-03-28 21:56 ` Brian Rogoff
2001-03-29 8:18 ` Mats Karlssohn
2001-03-29 8:11 ` Mats Karlssohn
2001-03-29 14:37 ` Ted Dennison
2001-03-29 16:35 ` Mark Biggar
2001-03-29 19:27 ` Florian Weimer
2001-03-29 19:28 ` Florian Weimer
2001-03-30 3:41 ` Ken Garlington
2001-03-30 4:32 ` Brian Rogoff
2001-03-30 14:27 ` Compile time executed functions [OT] Karel Thönissen
2001-03-30 17:30 ` Scheveningen (Re: Compile time executed functions [OT]) Ray Blaak
2001-03-30 17:39 ` More {OT] (Was " Brian Rogoff
2001-03-30 23:39 ` Karel Thönissen
2001-03-30 17:47 ` Compile time executed functions Brian Hanson
2001-03-30 0:06 ` Robert A Duff
2001-03-30 15:02 ` Ted Dennison
2001-03-30 20:57 ` Robert A Duff
2001-04-02 14:26 ` Ted Dennison
2001-03-30 17:33 ` Ray Blaak
2001-03-29 8:25 ` Florian Weimer
2001-03-28 7:17 ` Mats Karlssohn
2001-03-29 1:35 ` Jon S Anthony
2001-03-27 14:39 ` Robert A Duff
2001-03-27 15:09 ` Ted Dennison
2001-03-27 16:33 ` Robert A Duff
2001-03-27 23:36 ` Ken Garlington
2001-03-28 20:47 ` Mark Lundquist
2001-03-28 7:29 ` Mats Karlssohn
2001-03-28 22:15 ` Robert A Duff
2001-03-29 8:43 ` Mats Karlssohn
2001-03-31 4:12 ` Robert A Duff
2001-04-05 7:06 ` Mats Karlssohn
2001-04-13 23:18 ` Robert A Duff
2001-03-29 5:02 ` Ken Garlington
2001-03-28 7:31 ` Mats Karlssohn
2001-03-30 8:57 ` Georg Bauhaus
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