C interpreter in Lisp/scheme/python
bolega
For this, I propose a vanilla C interpreter. I have seen a book which
writes C interpreter in C.
The criteria would be the small size and high readability of the code.
Are there already answers anywhere ?
How would a gury approach such a project ?
Bolega
Vinay
Gene
Probably doesn't meet your intent, but this is a really impressive bit
of (whacky) art:
http://www.ioccc.org/1996/august.hint
and find the code at
http://www.ioccc.org/years-spoiler.html
under 1996.
nanothermite911fbibustards
Take a look at this
When I first got a summer job at MIT’s Project MAC almost 30 years
ago, I was
delighted to be able to work with the DEC PDP-10 computer, which was
more fun
to program in assembly language than any other computer, bar none,
because of
its rich yet tractable set of instructions for performing bit tests,
bit masking, field
manipulation, and operations on integers. Though the PDP-10 has not
been manufactured
for quite some years, there remains a thriving cult of enthusiasts who
keep old PDP-10 hardware running and who run old PDP-10 software—
entire
operating systems and their applications—by using personal computers
to simulate
the PDP-10 instruction set. They even write new software; there is now
at
least one Web site whose pages are served up by a simulated PDP-10.
(Come on,
stop laughing—it’s no sillier than keeping antique cars running.)
I also enjoyed, in that summer of 1972, reading a brand-new MIT
research
memo called HAKMEM, a bizarre and eclectic potpourri of technical
trivia.1 The
subject matter ranged from electrical circuits to number theory, but
what intrigued
me most was its small catalog of ingenious little programming tricks.
Each such
gem would typically describe some plausible yet unusual operation on
integers or
bit strings (such as counting the 1-bits in a word) that could easily
be programmed
using either a longish fixed sequence of machine instructions or a
loop, and then
show how the same thing might be done much more cleverly, using just
four or
three or two carefully chosen instructions whose interactions are not
at all obvious
until explained or fathomed. For me, devouring these little
programming nuggets
was like eating peanuts, or rather bonbons—I just couldn’t stop—and
there was a
certain richness to them, a certain intellectual depth, elegance, even
poetry.
“Surely,” I thought, “there must be more of these,” and indeed over
the years I
collected, and in some cases discovered, a few more. “There ought to
be a book of
them.”
I was genuinely thrilled when I saw Hank Warren’s manuscript. He has
systematically
collected these little programming tricks, organized them
thematically,
and explained them clearly. While some of them may be described in
terms of
machine instructions, this is not a book only for assembly language
programmers.
The subject matter is basic structural relationships among integers
and bit strings
in a computer and efficient techniques for performing useful
operations on them.
These techniques are just as useful in the C or Java programming
languages as
they are in assembly language.
Many books on algorithms and data structures teach complicated
techniques
for sorting and searching, for maintaining hash tables and binary
trees, for dealing
with records and pointers. They overlook what can be done with very
tiny
pieces of data—bits and arrays of bits. It is amazing what can be done
with just
binary addition and subtraction and maybe some bitwise operations; the
fact that
the carry chain allows a single bit to affect all the bits to its left
makes addition a
peculiarly powerful data manipulation operation in ways that are not
widely
appreciated.
Yes, there ought to be a book about these techniques. Now it is in
your hands,
and it’s terrific. If you write optimizing compilers or high-
performance code, you
must read this book. You otherwise might not use this bag of tricks
every single
day—but if you find yourself stuck in some situation where you
apparently need
to loop over the bits in a word, or to perform some operation on
integers and it just
seems harder to code than it ought, or you really need the inner loop
of some integer
or bit-fiddly computation to run twice as fast, then this is the place
to look. Or
maybe you’ll just find yourself reading it straight through out of
sheer pleasure.
source
http://www.hackersdelight.org./foreword.pdf
=======
Standard Disclaimer, nothing personal
http://www.youtube.com/watch?v=lX18zUp6WPY
http://www.youtube.com/watch?v=XQapkVCx1HI
http://www.youtube.com/watch?v=tXJ-k-iOg0M
Hey Racist and INcompetent FBI Bustards, where is the ANTHRAX Mailer ?
Where are the 4 blackboxes ? Where are the Pentagon Videos ? Why did
you release the 5 dancing Israelis compromising the whole 911
investigation ? If the Dubai Police can catch Mossad Murderers and put
the videos and Iranian Police can why cant you put the Pentagon
Videos ? If Iran police can put the AMERICAN TERRORIST, Riggi and
puting on INTERNATIONAL MEDIA a day after catching him without
TORTURE, why cant you put the INNOCENT patsies on the MEDIA. Why did
you have to LIE about Dr Afiya Siddiqui and torture that Innocent
little mother of 3 and smashing the skull of her one child ?
http://www.youtube.com/watch?v=DhMcii8smxk
http://www.youtube.com/watch?v=0SZ2lxDJmdg
There are CRIMINAL cases against CIA CRIMINAL Bustards in Italian
courts.
FBI bustards paid a penalty of $5.8 million to Steven Hatfill, but
only because he was a white. They got away with MURDER of thousands of
Non-whites in all parts of the world.
Daily 911 news : http://911blogger.com
http://www.youtube.com/watch?v=tRfhUezbKLw
nanothermite911fbibustards
> of (whacky) art:
Lisp runs faster than C. Once you get more time away from screwing
Palestinians, and other false-flags, you will find ideas like these
How to make Lisp go faster than C
Didier Verna
Abstract
Contrary to popular belief, Lisp code can be very ef-
cient today: it can run as fast as equivalent C code
or even faster in some cases. In this paper, we explain
how to tune Lisp code for performance by introducing
the proper type declarations, using the appropriate
data structures and compiler information. We also
explain how e ciency is achieved by the compilers.
These techniques are applied to simple image process-
ing algorithms in order to demonstrate the announced
performance on pixel access and arithmetic operations
in both languages.
Albert van der Horst
He would have his 10 year LISP sink in, meditate for 10 days and
start from scratch with a typical LISP approach.
He would have his 10 year Algol68 sink in, meditate for 10 days and
start from scratch with a typical Algol68 approach.
(Scheme is not different enough from LISP, to make this interesting.
Hey Scheme *is* a dialect of LISP.)
He would have his 10 year Python sink in, meditate for 10 days and
start from scratch with a typical Python approach.
Maybe he would code "one to throw away".
The outcome would be extremely interesting, but ...
>
>Bolega
Groetjes Albert
--
--
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst
fortunatus
Holy cow has this gone off topic! To OP - start writing a C context
free grammar of a subset of C (arithmetic expressions IMHO are the
historical root of C and a good place to start in any case), start
writing a parser of a subset of your subset grammar (in a lisp of your
chioce - Scheme and CL for instance are going to be pretty much
equivalent in this task), and really the rest will be obvious...
I'd go that far before posting on the topic again...
Stefan Monnier
I think, only someone who hasn't written such a beast can put together
"vanilla" and "C interpreter" together.
Stefan
Tim Rentsch
writes:
>> Probably doesn't meet your intent, but this is a really impressive bit
>> of (whacky) art:
>
> Lisp runs faster than C. Once you get more time away from screwing
> Palestinians, and other false-flags, you will find ideas like these
>
> How to make Lisp go faster than C
> Didier Verna
> [snip]
Asking whether Lisp is faster than C is like asking why it's
colder in the mountains than it is in the summer.
Define Macro
Maybe instead of full C, you should try something simplified, like
Tiny-C (http://primepuzzle.com/tc/) or Arena, or maybe even Pike (some
minimal variant thereof).
Richard Bos
> nanothermite911fbibustards <nanothermite9...@gmail.com>
>
> > How to make Lisp go faster than C
> > Didier Verna
>
> Asking whether Lisp is faster than C is like asking why it's
> colder in the mountains than it is in the summer.
YM warmer.
HTH; HAND.
Richard
Richard Bos
You think wrong. There is no reason to believe it impossible[1] to write
a vanilla C interpreter. In fact, it's probably slightly easier to
ensure that your implementation is _exactly_ vanilla if you make it an
interpreter rather than a compiler.
The real question is whether it's worth the trouble, writing an
interpreter and then only providing vanilla C. Presumably for didactic
reasons it could.
Richard
[1] It's certainly possible to write a C interpreter, because it's been
done; but I don't know how vanilla they are.
Michele Simionato
This look like a huge project for an evaluation of expressiveness
which result is obvious. Lisp (including Scheme) is more expressive
than Python, for many definitions of expressiveness (see for instance
http://www.ccs.neu.edu/scheme/pubs/scp91-felleisen.ps.gz if you like
academic papers). However, who cares? What matters in everyday life
are other things, like the availability of libraries, tools, easy of
maintenance, etc.
In your proposed project the choice of the parsing library would
matter a lot. Writing languages is a domain where Lisp is
traditionally strong, so you may find good libraries to help you with
the task. My guess is that it would take more or less the same amount
of effort both in Python and in Lisp. The place where Lisp has an
advantage is writing an *embedded* language: then thanks to macros you
could write a *compiled* sublanguage. Doing the same in Python is
essentially impossible.
Michele Simionato
Rivka Miller
You should probably narrow down your project to one. For example,
write a LISt Processor Meta Circular Evaluator in C.
You can take Paul Graham's rendition as a start and forget about
garbage collection.
Start with getchar()/putchar() for I/O.
Although C comes with a regex library, you probably do not need a
regex or parser at all for this. This is the beauty of LISP which is
why McCarthy was able to bypass the several man years of effort
involved in FORmula TRANslator. Even as a young boy like L. Peter
Deutsch was able to write it in assembly for one of the PDP's.
You will have go implement an associative array or a symbol-value
table probably as a stack or linked list. You will have to decide how
you implement the trees, as cons cells or some other method. Dynamic
scoping is easy to implement and that is what elisp has. I am not
aware of any book that provides implementation of LISP in C and
explains it at the same time.
This is the extent of help I can provide, someone else can probably
help you more.
Anyone know what the first initial of L. Peter Deutsch stand for ?
Rivka
wolfgang.riedel
> nanothermite911fbibustards <nanothermite911fbibusta...@gmail.com>
> writes:
>
> Asking whether Lisp is faster than C is like asking why it's
> colder in the mountains than it is in the summer.
original Karl Valentin would be <colder outside than nighttime>
but yours is in his sense.
Wolfgang
Nick Keighley
> Although C comes with a regex library,
C does not come with a regexp library
> Anyone know what the first initial of L. Peter Deutsch stand for ?
Laurence according to wikipedia (search time 2s)
Nick Keighley
wrote:
> On 7 July, 17:38, Rivka Miller <rivkaumil...@gmail.com> wrote:
> > Anyone know what the first initial of L. Peter Deutsch stand for ?
>
> Laurence according to wikipedia (search time 2s)
oops! He was born Laurence but changed it legally to "L." including
the dot
Pascal J. Bourguignon
Too bad, "Laurence" is a nice name.
--
__Pascal Bourguignon__ http://www.informatimago.com/
Mark Tarver
Probably you want to look at this thread
where I specified a toy language Minim (much simpler than C) and the
goal was to construct an interpreter for it. Similar problem.
Many solutions were given in different languages. The thread is very
long.
One thing you might look at is whether some sort of lexer/parser is
supported in any of your targets. Qi supports a compiler-compiler Qi-
YACC that allows you to write in BNF which makes this kind of project
much easier.
See
http://www.lambdassociates.org/Book/page404.htm
for an overview
Mark
George Neuner
Bourguignon) wrote:
>Nick Keighley <nick_keigh...@hotmail.com> writes:
>> Nick Keighley <nick_keighley_nos...@hotmail.com> wrote:
>>> Rivka Miller <rivkaumil...@gmail.com> wrote:
>>
>>>> Anyone know what the first initial of L. Peter Deutsch stand for ?
>>>
>>> Laurence according to wikipedia (search time 2s)
>>
>> oops! He was born Laurence but changed it legally to "L." including
>> the dot
>
>Too bad, "Laurence" is a nice name.
He probably hates the nickname "Larry".
bolega
> Define Macro wrote:
> > On Jun 13, 7:07 pm, bolega <gnuist...@gmail.com> wrote:
> >> I am trying to compare LISP/Scheme/Python for their expressiveness.
>
> >> For this, I propose a vanilla C interpreter. I have seen a book which
> >> writes C interpreter in C.
>
> >> The criteria would be the small size and high readability of the code.
>
> >> Are there already answers anywhere ?
>
> another suggest how to write an interpreter and perhaps a compiler too
> for some language. Anyone taking a course on compilers is likely to
> have followed such exercises in order to pass the course. Some
> instructors are enlightened enough to allow students to pick the
> implementation language.
>
> Ask any such instructor.
Beware, he does not tell the readers the financial details. This is
what he wrote to me by email.
<quote>
I would be willing to meet with you here in Berkeley to educate you on
these matters at a consulting rate of $850 per hour, with a minimum
of 8 hours.
RJF
</quote>
> I think you will find that many people use a packaged parser-generator
> which eliminates much of the choice-of-language difference. Do you like
> Bison, Yacc, Antlr, or one of the many parser generators in Lisp,
> python, etc.
>
> My own experience is that in comparing Lisp to C, students end up with
> smaller and better interpreters and compilers, faster. I don't know
> about python vs C for sure, but I suspect python wins. As for
> python vs Lisp, I don't know.
>
> RJF
bolega
> On Tue, Jul 13, 2010 at 11:01 PM, bolega <gnuist...@gmail.com> wrote:
> > On Jun 20, 9:31 pm, Richard Fateman <fate...@cs.berkeley.edu> wrote:
> >> Define Macro wrote:
> >> > On Jun 13, 7:07 pm, bolega <gnuist...@gmail.com> wrote:
> >> >> I am trying to compare LISP/Scheme/Python for their expressiveness.
>
> >> >> For this, I propose a vanilla C interpreter. I have seen a book which
> >> >> writes C interpreter in C.
>
> >> >> The criteria would be the small size and high readability of the code.
>
> >> >> Are there already answers anywhere ?
>
> >> Sure. Lots of texts on compilers provide exercises which, in one way or
> >> another suggest how to write an interpreter and perhaps a compiler too
> >> for some language. Anyone taking a course on compilers is likely to
> >> have followed such exercises in order to pass the course. Some
> >> instructors are enlightened enough to allow students to pick the
> >> implementation language.
>
> >> Ask any such instructor.
>
> > Beware, he does not tell the readers the financial details. This is
> > what he wrote to me by email.
>
> > <quote>
> > I would be willing to meet with you here in Berkeley to educate you on
> > these matters at a consulting rate of $850 per hour, with a minimum
> > of 8 hours.
>
> > RJF
> > </quote>
>
> common lisp was a twinkle in anybody's eye. His time is valuable.
>
> Geremy Condra
This makes some sense. He replied on the newsgroup in a lengthy post
that there are sufficient resources out there giving hint that no one
need help me out. Then I was called "lazy" in one email and tersely
given JUST the last name of an author who has many books each many
100s pages, when I asked for a relevant book, as if i am a scholar in
the field, although he did spend lots of words on irrelevant and
unbeneficial things which diminished my enthusiasm. Now, I find out
from you that he has/had a business concern or interest in a company
that is writing/wrote lisp interpreter in C. Correct me if I am making
an error. I dont want to think deprecatingly of any good soul but this
is what i experienced.
bolega
> bolega <gnuist...@gmail.com> writes:
> > I am trying to compare LISP/Scheme/Python for their expressiveness...
> > Are there already answers anywhere ?
> > How would a gury approach such a project ?
>
>
> http://page.mi.fu-berlin.de/~prechelt/Biblio/jccpprt_computer2000.pdf
> http://www.haskell.org/papers/NSWC/jfp.ps
>
> about language comparisons (Python is in the first but not the second)
> might be of interest.
>
> If you want to know how to implement C, there is a pretty good book by
> Hanson and Fraser about LCC, called "A Retargetable C Compiler".
> Basically a code walkthrough of a small C compiler written in C.
I have decided to limit my goal to tyni LISP interpreter in C because
its a smaller and simpler language.
Seebs
> This makes some sense. He replied on the newsgroup in a lengthy post
> that there are sufficient resources out there giving hint that no one
> need help me out. Then I was called "lazy" in one email and tersely
> given JUST the last name of an author who has many books each many
> 100s pages, when I asked for a relevant book, as if i am a scholar in
> the field, although he did spend lots of words on irrelevant and
> unbeneficial things which diminished my enthusiasm.
If you found those "irrelevant and unbeneficial", then while I agree that he
may have been wasting his time, he would have been wasting it even worse
trying to walk you through the technical material when you're clearly
not currently at a stage where you are ready to learn anyway.
> Now, I find out
> from you that he has/had a business concern or interest in a company
> that is writing/wrote lisp interpreter in C. Correct me if I am making
> an error. I dont want to think deprecatingly of any good soul but this
> is what i experienced.
If you are trying to imply that he was acting in some unethical way, you have
further cemented the notion that trying to talk to you is a waste of anyone's
time. *plonk*
-s
--
Copyright 2010, all wrongs reversed. Peter Seebach / usenet...@seebs.net
http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures
http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated!
francogrex
googlegroups.com>, gnui...@gmail.com says...
>This makes some sense. He replied on the newsgroup in a lengthy
post
>that there are sufficient resources out there giving hint that
no one
>need help me out. Then I was called "lazy" in one email and
tersely
>given JUST the last name of an author who has many books each
many
>100s pages, when I asked for a relevant book, as if i am a
scholar in
>the field, although he did spend lots of words on irrelevant and
>unbeneficial things which diminished my enthusiasm. Now, I find
out
>from you that he has/had a business concern or interest in a
company
>that is writing/wrote lisp interpreter in C. Correct me if I am
making
>an error. I dont want to think deprecatingly of any good soul
but this
>is what i experienced.
No, you're not making a bad judgement. He's not the only one who
treats newcomers with disrespect and scorn. Unfortunately many
so-called experts in the field look down on newbies and mistreat
them (in any programming language forum), forgetting in the
process that they were also at a certain time newbies until
someone gentle and nice enough teachers took the trouble to
educate them. On the other hand there are less neurotic experts
out there who are glad to help out someone learning. It's like in
some universities, you have the bad "professors" who are freaks
(probably they have a lot of problems at home, their wives
screwing all the males on the block, daughters drug addicts etc)
and want to take their hatred out on you, and you have the
good and mentally stable professors who actually deserve their
title.
George Neuner
wrote:
>Unfortunately many so-called experts in the field look down
>on newbies and mistreat them (in any programming language forum),
>forgetting in the process that they were also at a certain time
>newbies until some gentle and nice enough teachers took the
>trouble to educate them.
I don't think it's accurate to say that [some] experts really "scorn"
newbies, but I do agree that newbies are occasionally mistreated.
One thing newbies have to realize is that on Usenet you are quite
likely to be talking to people who were there at the beginning and, of
necessity, are largely self educated in whatever the subject matter
might be. Many - I'd even say most - are happy to clarify
understanding and help with complicated problems, but there is a
general expectation that newbies have some basic research skills and
that they have tried to solve their problem before asking for help.
Unfortunately, there is a small percentage of people who think Usenet
and other online forums are for answering homework questions or for
digging out of a jam at work. Getting help depends a lot on how the
question is asked: strident pleas for quick help or demands for an
answer are immediate red flags, but so are questions that begin with
"X is crap, why can't I do ..." and even seemingly polite questions
that are vague or unfocused (possibly indicating little or no thought
behind them) or posts which are directed to a large number of groups
(such as this thread we're in now).
And, of course, in the language forums, drawing comparisons to
non-subject languages is generally considered rude except when done to
illustrate a relevant discussion point. Introducing irrelevant
comparisons, deliberately proselytizing X in a Y group or doing a lot
of complaining about the subject language is bound to attract disdain.
As the Internet has grown, the absolute number of people in that
"small percentage" has grown as well. A newbie can simply be unlucky
enough to ask a question at the wrong time. If there has been a
recent rash of problem posts then experts may accidentally respond
negatively to a legitimate question.
Of course, there are cross-cultural issues too. Many of the technical
groups are English-language. English, even when polite, can seem
harsh and/or abrupt to non-native speakers.
On the whole, moderated groups are more conducive to helping newbies
because the moderator(s) filter obvious red flag posts.
And, finally, newbies themselves should realize that experts are
donating time to answer questions and do get frustrated answering the
same questions over and over. They should not be offended by "cold"
responses that direct them to FAQs or that just give links to study
material. Newbies who need hand-holding or warm welcoming responses
filled with detail should go find a tutor.
> ... you have the bad "professors" who are freaks
>(probably they have a lot of problems at home, their wives
>screwing all the males on the block, daughters drug addicts etc)
>and want to take their hatred out on you,
Unquestionably, there are experts who need their dosages adjusted. But
the same can be said for some percentage of other users too.
OTOH, newbies often aren't in the position to know who is an expert
... obviously, anyone able to correctly answer their question knows
more about that specific issue. That doesn't necessarily qualify the
responder as an "expert". Some people get defensive at the edges of
their comfort zones.
Just some thoughts. YMMV.
George
francogrex
says...
Yes I agree, you expressed the thought better than I did. Then let's not go on
with this thread any further and let the newsgroups carry on programming
language support and discussions. Thanks