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Groups > comp.lang.forth > #38652
| From | anton@mips.complang.tuwien.ac.at (Anton Ertl) |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: SET-COMPILER |
| Date | 2015-04-27 14:52 +0000 |
| Organization | Institut fuer Computersprachen, Technische Universitaet Wien |
| Message-ID | <2015Apr27.165232@mips.complang.tuwien.ac.at> (permalink) |
| References | <54c266b4-17d8-4d0d-adc6-8b7ab0bcc0f4@googlegroups.com> |
JennyB <jennybrien@googlemail.com> writes:
>It seems confusing to me to have rules for the interpretation and compilation behavior of Standard words that user-defined don't follow.
User-defined words also follow the rules laid out in the standard.
>At present:
>
> All user-defined words are tickable and return an xt that can be EXECUTEd. Whether it is designed to be executed while interpreting or while compiling, or both, is the user's decision.
Sure, what they are designed to do is up to the programmer. All
user-defined words have both interpretation and compilation semantics.
> FIND returns the xt and a flag - 1 if the word is to be executed while compiling (IMMEDIATE), or -1 otherwise, in which case the compiler does whatever it is designed to do with COMPILE, which may or may not include fairly complex optimising.
>
>IMMEDIATE is presently the only way for the user define special compiling behavior. If you want a word to word during interpretation and its compiling behavior in inappropriate, then you have two choices:
>
> Write two separate words, one for interpreting and one for compiling, and use them appropriately.
>
> Wrap them into one STATE-smart word and live with the gotcha of depending on run-time STATE.
>
>So we want a way for the user to define early-binding compiling behavior for non-IMMEDIATE words (IMMEDIATE words, by definition, already define early-binding compiling behavior - unless they are STATE-smart) without breaking the familiar rules.
>
>So:
>SET-COMPILER doesn't make sense on IMMEDIATE words, :NONAMEs, or, I would guess, on SYNONYMs.
You are conflating two very different things: optimization and
compilation semantics. You are not alone in this mistake, and I'll
explore here why.
Let's start with optimization. Optimization means it does the same
semantics, but more efficiently.
As an example, let's take a simple example of a simple word: 2DUP
: 2dup over over ;
Now suppose your compiler does not do inlining by itself, so when you write
: foo ... 2dup ... ;
it will compile a call to your colon definition. You want it to
expand this into OVER OVER instead. So you tell COMPILE, to generate
over over instead of a call to 2DUP:
: 2dup over over ;
comp: drop postpone over postpone over ;
(This is VFX syntax); and this works even if you disable inlining:
[-sin
: foo 2dup ;
see foo
So in this case the COMP: provides a new implementation of the same
compilation semantics as the original word. In other words: this
implementation of 2DUP has the default compilation semantics, just a
more efficient implementation. You can do the code generation of all
the primitives of a native-code compiler with such a mechanism. And
that (implementing what COMPILE, would otherwise do, only more
efficiently) is the only thing that you should do with a mechanism
that changes what COMPILE, does with a word, such as COMP: or
SET-COMPILER.
Unfortunately, this is not where the story ends. As you write, there
are those who want words that do one thing when text-interpreted in
interpret state and another thing when text-interpreted in compile
state; such words are even in the standard (e.g., S"). Now once they
have a mechanism such as COMP:, they get the idea to use it not only
for optimization, but also for changing compilation semantics. This
idea comes from the observation that text interpreters tend to work as
follows:
find state @ if \ compile state?
if 0< if \ non-immediate?
compile,
else
execute
then
else
execute
then
So the idea of misusing COMP: for implementing arbitrary combinations
of interpretation and compilation semantics is this:
: foo
interpretation-semantics-of-foo ;
comp: drop compilation-semantics-of-foo ;
This will work as intended in the text interpreter outlined above: It
will perform the intended interpretation semantics when
text-interpreted in interpretation state, and it will perform the
intended compilation semantics when text-interpreted in compilation
state.
However, COMPILE, is not only used in the text interpreter. It is
used in other contexts, in particular in contexts where it is a a kind
of delayed EXECUTE (examples: early binding in OOP packages, or macros
with xt parameters). If you change what semantics COMPILE, compiles
for an xt, these uses break.
Now Bernd tells me that I should not worry, that nobody will use the
xts of words like FOO in these contexts. However, given the immense
creativity of Forth programmers in exploiting various aspects of Forth
systems, I don't find this at all reassuring.
My conclusion: Let's get rid of words with arbitrary combinations of
interpretation an compilation semantics. In the meantime, dual-xt
words are the right way to implement them.
- anton
--
M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
New standard: http://www.forth200x.org/forth200x.html
EuroForth 2014: http://www.euroforth.org/ef14/
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SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-27 01:34 -0700
Re: SET-COMPILER stephen@mpeforth.com (Stephen Pelc) - 2015-04-27 14:52 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-27 21:17 +0200
Re: SET-COMPILER hughaguilar96@gmail.com - 2015-04-28 09:41 -0700
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-04-27 16:53 +0100
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-04-27 17:02 +0100
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-27 10:23 -0700
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-27 10:02 -0700
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-01 17:15 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-01 23:38 +0200
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-27 14:52 +0000
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-04-27 17:09 +0100
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-04-27 16:54 +0000
Re: SET-COMPILER stephen@mpeforth.com (Stephen Pelc) - 2015-04-28 09:11 +0000
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-28 04:28 -0700
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-29 13:49 -0700
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-30 00:13 +0200
Re: SET-COMPILER stephen@mpeforth.com (Stephen Pelc) - 2015-04-30 06:32 +0000
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-30 05:22 -0700
Re: SET-COMPILER stephen@mpeforth.com (Stephen Pelc) - 2015-04-30 15:27 +0000
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-04-30 19:16 +0100
Re: SET-COMPILER stephen@mpeforth.com (Stephen Pelc) - 2015-04-30 21:08 +0000
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-04-30 23:05 +0100
Re: SET-COMPILER hughaguilar96@gmail.com - 2015-04-30 15:47 -0700
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-01 12:29 +0100
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 15:25 +0000
Re: SET-COMPILER hughaguilar96@gmail.com - 2015-04-30 17:07 -0700
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-01 02:40 -0700
Re: SET-COMPILER stephen@mpeforth.com (Stephen Pelc) - 2015-05-01 10:24 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-01 22:55 +0200
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-02 01:32 -0700
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 16:27 +0000
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-03 08:36 -0700
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-04 16:44 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 15:37 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-01 01:33 +0200
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-01 03:15 -0700
Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-01 12:47 +0000
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-01 10:29 -0700
Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-01 20:32 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 15:51 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 15:29 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 14:59 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-04 16:11 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 12:04 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-04-28 03:22 +0200
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 11:09 +0000
Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-02 12:30 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 16:58 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-02 20:42 +0200
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-04 16:28 +0000
Re: SET-COMPILER Mark Wills <markwills1970@gmail.com> - 2015-05-06 04:14 -0700
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-04-27 23:57 -0700
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 11:41 +0000
Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-02 12:51 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-02 17:00 +0000
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-03 11:19 +0100
Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-03 07:30 -0700
Re: SET-COMPILER Coos Haak <chforth@hccnet.nl> - 2015-05-03 21:45 +0200
Re: SET-COMPILER Coos Haak <chforth@hccnet.nl> - 2015-05-03 21:48 +0200
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-05 22:03 +0100
Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-05 22:56 +0000
PREFIX JennyB <jennybrien@googlemail.com> - 2015-05-06 02:30 -0700
Re: PREFIX anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-06 12:23 +0000
Re: PREFIX "Alex McDonald" <blog@rivadpm.com> - 2015-05-06 16:44 +0100
Re: PREFIX anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-06 16:03 +0000
Re: PREFIX "Alex McDonald" <blog@rivadpm.com> - 2015-05-06 17:40 +0100
Re: PREFIX albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-06 19:44 +0000
Re: PREFIX Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-06 22:05 +0200
Re: PREFIX Bernd Linsel <bl1@gmx.com> - 2015-05-07 04:23 +0200
Re: PREFIX anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-08 11:48 +0000
Re: PREFIX anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-08 12:04 +0000
Re: PREFIX anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-08 11:55 +0000
Re: PREFIX "Alex McDonald" <blog@rivadpm.com> - 2015-05-06 14:20 +0100
Re: PREFIX albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-06 19:41 +0000
Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-06 12:29 +0000
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-06 15:07 +0100
Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-09 03:02 -0700
Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-09 17:23 +0100
Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-11 08:07 +0100
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-11 11:20 +0100
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-12 10:05 -0700
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-12 18:34 +0100
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-12 12:07 -0700
Re: Recognizer RfD was Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-12 22:11 +0200
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-12 21:35 +0100
Re: Recognizer RfD was Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-13 01:31 +0200
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-13 16:20 +0000
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-13 12:20 -0700
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-13 22:24 +0100
Re: Recognizer RfD was Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-14 11:26 +0000
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-14 11:00 -0700
Re: Recognizer RfD was Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-14 08:06 -0700
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-14 17:21 +0100
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-14 11:31 -0700
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-14 19:41 +0100
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-14 11:49 -0700
Re: Recognizer RfD was Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-15 09:41 +0000
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-15 12:19 +0100
Re: Recognizer RfD was Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-15 14:42 +0000
Re: Recognizer RfD was Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-15 10:37 -0700
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-15 23:00 +0100
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-16 13:52 +0000
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-16 19:24 +0100
Re: Recognizer RfD was Re: SET-COMPILER Matthias Trute <matthias.trute@gmail.com> - 2015-05-16 13:26 -0700
Re: Recognizer RfD was Re: SET-COMPILER Coos Haak <chforth@hccnet.nl> - 2015-05-17 00:27 +0200
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-17 10:03 +0000
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-17 23:25 +0100
Re: Recognizer RfD was Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-15 10:02 +0000
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-15 12:35 +0100
Re: Recognizer RfD was Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-15 15:33 +0000
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-15 14:01 +0000
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-15 13:14 +0000
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-13 17:07 +0000
Re: Recognizer RfD was Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-14 03:27 +0200
Re: Recognizer RfD was Re: SET-COMPILER hughaguilar96@gmail.com - 2015-05-13 19:23 -0700
Re: Recognizer RfD was Re: SET-COMPILER JennyB <jennybrien@googlemail.com> - 2015-05-14 01:08 -0700
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-13 14:30 +0000
Re: Recognizer RfD was Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-14 03:40 +0200
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-15 13:26 +0000
Re: Recognizer RfD was Re: SET-COMPILER "Alex McDonald" <blog@rivadpm.com> - 2015-05-12 21:33 +0100
Re: Recognizer RfD was Re: SET-COMPILER albert@spenarnc.xs4all.nl (Albert van der Horst) - 2015-05-13 10:36 +0000
Re: Recognizer RfD was Re: SET-COMPILER anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-05-13 16:06 +0000
Re: SET-COMPILER Bernd Paysan <bernd.paysan@gmx.de> - 2015-05-03 20:38 +0200
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