8 ms·

Show HN: SectorLISP now fits in one sector

323 points by jart 5y ago

agumonkey 5y ago
These sorts of minimalist bare metal abstract PL articles are so thrilling to me. APL comes to mind. I wonder how high you can go with only 1MB say.
- tluyben2 5y ago
  k9 [0], an APL like, is under 160KB and includes a database in that. [0] https://shakti.com https://shakti.com
  - agumonkey 5y ago
    I shall gather all these projects on a wiki.
- p_l 5y ago
  L - an embedded subset of Common Lisp used in Roomba, ran in 1MB of ram total afaik including compiler and support OS.
  - agumonkey 5y ago
    oh wow, roombas still run this subset of CL ?? ps: ohh that paper was on the frontpage not long ago, I just didn't realize it was used in Roombas
  - terafo 5y ago
    1MB is really a lot if you know what you're doing, what language you actually can't fit into 1MB of ram due to inherent specifics of language itself, not because interpreter/compiler doesn't optimize for such cases?
- pjmlp 5y ago
  A lot, we only had 640KB to play with on most MS-DOS, Amiga and Atari computers, and 8bits had 64-128 KB.
  - agumonkey 5y ago
    hmm but were there high level languages being usable on these ? I remember a CLISP impl on some atari (but I think the dev had a ram addon). all in all, I'd really love to have or make a 1MB minimalistic shell with a tiny lisp/prolog/smalltalk
    - pjmlp 5y ago
      Plenty of them, here is a non-exaustive list. C, C++, Modula-2, Pascal, AMOS, Clipper, FoxPro, Turbo Basic, Quick Basic, Turbo Prolog, PC-Lisp, Native Oberon,...
    - varjag 5y ago
      Most then existing HLLs were very usable in 640Kb. If you go down to 8-bits, while translators for many of these did exist the utility was rapidly diminishing. You'd essentially have system's native version of BASIC + assembler for anything practical. The rest were more of parlor tricks.
      - abecedarius 5y ago
        In that context Forth was quite practical. That was its heyday.
    - guenthert 5y ago
      INTERLISP was available for the Atari 800 (which max'd out at 48KiB RAM).
- adrian_b 5y ago
  1 MB is huge. Keep in mind that IBM PC/XT had only 640 kB, but there were compilers and interpreters for any language, which were available for it. Moreover, before IBM PC, a CP/M computer with Zilog Z80 or Intel 8080 had usually only 32 kB or 48 kB, but you could use without problems Basic interpreters, Pascal, Fortran, Cobol and PL/M compilers and many others. However, in order to fit in 32 kB, the compilers themselves were typically written using a macro-assembler, and not in a high-level language. The C language became popular for such tasks somewhat later.
  - User23 5y ago
    The original Macintosh had 128k and managed to load a graphical OS and an app in that space. The ROM certainly helped, but it was quite a feat.
  - Narishma 5y ago
    > Keep in mind that IBM PC/XT had only 640 kB And that's the maximum (without bank switching schemes like EMS). The first version had only 64 KB. There were even plans for a 16 KB version with no disk drive but I don't think it was ever released.
  - int_19h 5y ago
    The base model of ZX Spectrum only had 16 Kb, but it was enough for it to run BASIC. And then there's FORTH, which is tiny even in a naive implementation, but can be taken to extremes as well: https://pygmy.utoh.org/3ins4th.html https://pygmy.utoh.org/3ins4th.html
- akkartik 5y ago
  Assuming you mean static code size, my Mu project currently supports an interpreted Lisp (macros, fewer parens, infix) implemented in a compiled memory-safe low-level language without _any_ C in 450KB. The "runtime library" (mostly in the safe low-level language) requires 120KB. Without unit tests, the binary sizes drop down to 200KB and 30KB respectively, which gives you some sense of the space devoted to tests in each case. As the tests hint, Mu doesn't do anything to try to reduce code size. It's small just by focusing on the essentials. What's left is written for ease of comprehension. (An example of "essentials": Mu still cannot free memory. I run my programs in Qemu with 2GB which seems to suffice.) More details: https://github.com/akkartik/mu https://github.com/akkartik/mu
  - agumonkey 5y ago
    the variable/register idea is neat, I always wanted some veneer on top of raw registries.. almost like a cpu monad
  - jart 5y ago
    Author here. I assume you're referring to https://github.com/akkartik/mu/blob/main/shell/evaluate.mu https://github.com/akkartik/mu/blob/main/shell/evaluate.mu? It's hard for me to tell, since there's 819k lines of code in Mu according to find . -type f | grep -v '\.git' | xargs wc -l. Does it have lambda and support metacircular evaluation? If not, then why do you think it's LISP-like? If you do nothing to reduce code size, then why do you call it Mu? (I assume by "Mu" you're referring to what UNICODE calls the MICRO SIGN.) 30kb is two orders of a magnitude larger. I don't see how it's relevant to SectorLISP.
    - akkartik 5y ago
      Sorry to tramp over your thread! Mu isn't too related to SectorLISP, I was just responding to the side-discussion about what we can build in under 1MB. To answer your question, evaluate.mu does support lambda (I call it `fn`). My estimates of size were based on `ls -l a.bin` after `./translate shell/*.mu`. I actually didn't really think of the micro interpretation of 'mu' until years after I started the project. The interpretation I had in mind was https://en.wikipedia.org/wiki/Mu_(negative)#%22Unasking%22_the_question https://en.wikipedia.org/wiki/Mu_(negative)#%22Unasking%22_t...
- jacquesm 5y ago
  I wrote a full CAD/CAM suite for lathe/mill work in a few hundred K, working RAM was another 500K or so...
  - agumonkey 5y ago
    Honestly you and people writing similarly small applications should gather and write a book. I don't know if I'm an alien but whenever I see frugal yet non trivial application my brain rejoyces.
    - jacquesm 5y ago
      This was back when 1 MB was considered and amazing amount of memory. It took two years to write this, about 50K lines of high level code and another 10K or so of assembly. Today you would approach such a project in a completely different way, you'd use much more time to make it look pretty and just that part would probably be much larger than the whole package that I wrote. The funny thing is that even so many years later the original software is still in use in some places and there is a whole company centered around that core that has been re-written a couple of times to keep it up to date and to expand its functionality. I highly doubt the present day version would fit in something that small. What's interesting to me is that that old stuff tended to be super productive to work with, zero distractions, just some clearly defined task in a clearly defined environment, if it worked it was bullet proof. No hackers, SaaS, a million connectivity options and no eye candy. Just that one job to be done and done as good as the hardware would allow you to.
      - agumonkey 5y ago
        But that's exactly my point. I think we forgot to aim at super productive, zero distraction, lightweight. And it would be of high educative value to see this sort of work again. Both on the small scale details and the pragmatic value. The sad part to me is that most web apps reenact the same functions but in a css-transition-capable DOM. But functionally I'm not sure you get more.
        5y ago
- bob29 5y ago
  https://www.red-lang.org/p/about.html https://www.red-lang.org/p/about.html Almost as batteries-included as python.
  - agumonkey 5y ago
    Ha, I didn't know the whole distribution fit in 1MB. Thanks
  - diskzero 5y ago
    I love Red and want to use it more. Sadly my professional life keeps giving me hardware that I can't run it on, so Red is getting marginalized. I wish I had more skill and time to help them out with the 32 to 64-bit transition. [1] [1] https://gitter.im/red/red?at=5e09152cd5a7f357e6a1af83 https://gitter.im/red/red?at=5e09152cd5a7f357e6a1af83
tomcam 5y ago
jart makes me realize that my high school counselor Stella Sawicki was absolutely right when she said I wasn’t living up to my potential
- metagame 5y ago
  In your defense, Justine's been at this for a long time! Give it time and effort, and you too can do amazing technical things. Potential isn't a concrete thing, it's a set point you can move around. Throw yourself at the computer, and the computer will do interesting things with you, too. If it's not working, go at it from a different angle. Sometimes it's helpful to go back in time to come across things. I'd argue that 90% of cool tech phenomenon arises from studying the past to make something cooler in the future rather than any force of sheer will. A lot of Justine's projects seem to fit this mold (if I remember right she came across the idea for Cosmopolitan after finding that a legacy UNIX feature let you avoid specifying your shell; SectorLISP, McCarthy's metacircular, etcetera). She even cites someone whose entire deal is doing precisely that: Nils M. Holm.
  - eggy 5y ago
    Yes, Justine's amazing. I have also been following and reading Nils M. Holm's books. I program in J/APL, and I picked up Nils' book on Klong, but I have not fully worked through it yet. It gives me a perspective on J/APL. His Lisp stuff is great.
    - tluyben2 5y ago
      Nils his works are excellent; I always buy all that come out.
      - eggy 5y ago
        He's very prolific and the content is rich. I always feel I need to step up my game. People like Justine and Nils inspire me to keep at it!
mikewarot 5y ago
I didn't remember an FS register... it was added on the 386, I wonder what would happen if this was run on an old IBM XT? I realize that something had to go in order to fit it in the size limit, compatibility with 8088 CPUs isn't the worst choice. [Edit] Sorry if this sounded too negative... I'm astounded that it's even possible to do this in a sector at all.
- adrian_b 5y ago
  Intel 8086 and 8088 did not have invalid instruction exceptions. The opcodes that were not documented were either redundant, doing exactly the same thing as other documented opcodes, or they crashed the system. Later, in 1982, 80186 and 80286 introduced invalid opcode exceptions, so starting with the IBM PC/AT any program intended for later CPUs should abort with an error message. Most IBM PC/XT were made with Intel 8088, so the behavior of an 80386 program is unpredictable. Some PC/XT clones were made with 80186 or 80188, or, more frequently, with NEC V20 processors. All these had invalid opcode exceptions, so they should behave like a PC/AT.
- jart 5y ago
  It's not too negative because to be honest it's something I felt guilty about. It looks we actually have enough room left to fix that, since we're not currently using %bp. We even have room to add the necessary push/pop for %bp to work around a bug in the original IBM PC BIOS implementation. If we make that change, then I've just confirmed with xed -r -isa-set -i sectorlisp.o that's it's pure i8086 and should work. One of us should pull out an old IBM PC and record a video of sectorlisp running on the original hardware. Anyone want to volunteer? I have one but it's difficult for me to use since I only know how to type dvorak.
gavinray 5y ago
Every time I read something by Justine Tunney, I am continually reminded of my mediocrity. I once reached out to them personally to tell them I hope I can be like them when I grow up ;^) On a serious note, this is one of the coolest things I've ever seen. The person mentioned that helped them go from 700 -> 500 bytes, the said "Assembly Heisenberg" appears to be entirely obscure on GH too. Seems like the right set of eyes just happened to find their way to the project at the right time: https://github.com/agreppin https://github.com/agreppin I wish I was born like this.
- pmarreck 5y ago
  I was already impressed by this person's work when I read about APE (Actually Portable Executable)... Something that should really be a thing IMHO
- john-tells-all 5y ago
  Agreed, Jart's work is jaw-droppingly incredible, on the order of Fabrice Bellard's achievements. However, I don't see "I wish I was born like this" -- their works encourages me to think and do lots of crazy shit. My previous limitations were just a lack of imagination and creativity. SectorLISP also encourages the "do anything" viewpoint. The original version was published even though way larger than a sector. Other people contributed, sometimes only by publishing a related project (SectorFORTH). By having an idea and publishing something Justine created something unique. Lastly the above page shows the "run program and watch its memory in realtime" technique, which is incredible in itself. The tool is called Blinkenlights https://justine.lol/blinkenlights/ https://justine.lol/blinkenlights/
  - jart 5y ago
    It's a nice story about how sometimes the best way to ultimately succeed is to not be afraid to admit when something was tried and failed. By publishing SectorLISP in an unfinished state, I attracted a lot of smart people to the problem. Now that it's complete we can look back and say we did it.
veltas 5y ago
Not really on topic but I found myself looking around this website and this is easily the most interesting personal site I've seen on HN, and then from reading all the angry posts by the right people Justine also seems like the most interesting personality I've seen on here.
- gavinray 5y ago
  Agreed - As far site content that gets posted. I also like rachelbythebay. But for commenters, there are lots of interesting people.
- mark_l_watson 5y ago
  I also agree with you. My specialties are machine learning and knowledge graphs, very different than what Justine works on, yet I find digging into her posts fascinating.
  - jart 5y ago
    Justine here. I used to work on TensorBoard and I contributed a few hundred thousand lines of changes to TensorFlow. These are my hobby projects so we might not be as dissimilar as you think :-)
pmarreck 5y ago
Does this pass any tests to prove it is a general purpose lisp? (I suppose, writing a lisp evaluator in it might be such a test, but not 100% sure)
akkartik 5y ago
Why is this quoting the top-level lambda expression arguments? Unless I'm mistaken that's not how JMC did it. For example, to define a binding the cited resource http://www.paulgraham.com/rootsoflisp.html http://www.paulgraham.com/rootsoflisp.html uses (defun null (x) (eq x '())) Replacing the defun with an env binding, I believe the value translates to: (lambda (x) (eq x '())) I don't think this should be quoted? Even though lambda isn't typically assumed in the "seven primitives," it _is_ required by the runtime. Are your function calls implicitly dropping quotes when evaluating arguments?
- jart 5y ago
  Author here. The quotes are indeed needed. Emacs does the same thing. For example: ((lambda (x) (message "%S" x)) (1)) ;; fails: no such function `1' ((lambda (x) (message "%S" x)) (quote (1))) ;; prints (1) The original evaluator is defined so that if the first item of a list, is a list whose first item is LAMBDA, then what it does is it calls Evlis() and Pairlis() which is sort of like a glorified version of Python's zip() function, to attach all the subsequent list items to the parameter name list. ((LAMBDA (ARG1 ARG2 ARG3) <YOUR PROGRAM GOES HERE>) (QUOTE VAL1) (QUOTE VAL2) (QUOTE VAL3)) This is the "venus fly trap" that the blog post mentions. The process of evaluation causes the expression the clamp in on itself where the args get digested into an association list which can be referenced and then the payload is evaluated. This was all non-obvious to me, even after using LISP casually for years, since we normally don't write code that way. Now it's possible to add extra code to the evaluator so that if a naked lambda is encountered, i.e. it sees (LAMBDA ...) rather than ((LAMBDA ...) ...), it just lets it pass through, so you don't need the quotes. We did that originally, but deemed it non-essential and was removed, since that would have made it much harder to hit the 512-byte goal.
  - akkartik 5y ago
    By Emacs do you mean Elisp? Your session there is not surprising to me. I don't have emacs handy but what does this do? ((lambda (f) (f)) (lambda() 42)) You might need to throw a 'funcall in there or something, but my hypothesis is that this will work (return 42) without needing the top-level argument to be quoted. 'lambda is a deep special case, basically. I understand that functions always zip through their arguments, evaluating each one. But when you quote the args in the call, I tend to expect the arguments to not be evaluated within 'evlis. I'm surprised that quoting args makes the interpreter smaller! That's pretty interesting. But I think this interpreter will have some behavior that is surprising to anyone used to all extant lisps for examples like this: ((lambda (sym) (cons sym 3)) (quote a)) Here there's no binding for 'a. I expect this to return (a . 3) in JMC's original Lisp.
mastax 5y ago
Was still spooky downloading and executing the same blinkenlights binary on Windows and Linux (WSL). Unfortunately it doesn't actually work in either environment: Error: your CPUID command does not support command 0x80000006 (AMD-style L2 cache information). AMD Ryzen 7 1800X
- jart 5y ago
  Author here. What are you executing? It works fine on AMD Ryzen for me. That error message doesn't appear in the blinkenlights.com binary. It also doesn't perform that CPUID check. The only place I can find that error message online is for a fizzbuzz codegolf. Perhaps you're confusing sectorlisp with a another project? Also, Blinkenlights should work fine in the Windows 10 Command Prompt. So WSL isn't required but it does run on that too. https://justine.lol/sectorlisp/spooky.png https://justine.lol/sectorlisp/spooky.png
  - mastax 5y ago
    Oh, silly me. I hadn't noticed you need the `-t` flag to open the TUI and assumed that since the TUI didn't open that the error was from blinkenlights.
    - jart 5y ago
      Glad I could help. Hope you enjoy Das Blinkenlights. Press '?' for help. Useful shortcuts for controlling execution are 'c', 'C', Ctrl-C, Ctrl-T, and Alt-T. Memory panels can be scrolled with the mouse wheel. You can also zoom in or zoom out the memory display with ctrl mouse wheel, although that might not be available in CMD.EXE and you might need to use something like KiTTY, XTerm, or PuTTY.
Orangeair 5y ago
> According to The History of LISP, the same was true for LISP 1.0. Native integer support was added later as a performance optimization. I feel like this just distills the ethos of LISP so perfectly, I'm gonna use this to explain it to people now.

323 points by jart 5y ago

These sorts of minimalist bare metal abstract PL articles are so thrilling to me. APL comes to mind. I wonder how high you can go with only 1MB say.

tluyben2 5y ago
k9 [0], an APL like, is under 160KB and includes a database in that. [0] https://shakti.com https://shakti.com
- agumonkey 5y ago
  I shall gather all these projects on a wiki.
p_l 5y ago
L - an embedded subset of Common Lisp used in Roomba, ran in 1MB of ram total afaik including compiler and support OS.
- agumonkey 5y ago
  oh wow, roombas still run this subset of CL ?? ps: ohh that paper was on the frontpage not long ago, I just didn't realize it was used in Roombas
- terafo 5y ago
  1MB is really a lot if you know what you're doing, what language you actually can't fit into 1MB of ram due to inherent specifics of language itself, not because interpreter/compiler doesn't optimize for such cases?
pjmlp 5y ago
A lot, we only had 640KB to play with on most MS-DOS, Amiga and Atari computers, and 8bits had 64-128 KB.
- agumonkey 5y ago
  hmm but were there high level languages being usable on these ? I remember a CLISP impl on some atari (but I think the dev had a ram addon). all in all, I'd really love to have or make a 1MB minimalistic shell with a tiny lisp/prolog/smalltalk
  - pjmlp 5y ago
    Plenty of them, here is a non-exaustive list. C, C++, Modula-2, Pascal, AMOS, Clipper, FoxPro, Turbo Basic, Quick Basic, Turbo Prolog, PC-Lisp, Native Oberon,...
  - varjag 5y ago
    Most then existing HLLs were very usable in 640Kb. If you go down to 8-bits, while translators for many of these did exist the utility was rapidly diminishing. You'd essentially have system's native version of BASIC + assembler for anything practical. The rest were more of parlor tricks.
    - abecedarius 5y ago
      In that context Forth was quite practical. That was its heyday.
  - guenthert 5y ago
    INTERLISP was available for the Atari 800 (which max'd out at 48KiB RAM).
adrian_b 5y ago
1 MB is huge. Keep in mind that IBM PC/XT had only 640 kB, but there were compilers and interpreters for any language, which were available for it. Moreover, before IBM PC, a CP/M computer with Zilog Z80 or Intel 8080 had usually only 32 kB or 48 kB, but you could use without problems Basic interpreters, Pascal, Fortran, Cobol and PL/M compilers and many others. However, in order to fit in 32 kB, the compilers themselves were typically written using a macro-assembler, and not in a high-level language. The C language became popular for such tasks somewhat later.
- User23 5y ago
  The original Macintosh had 128k and managed to load a graphical OS and an app in that space. The ROM certainly helped, but it was quite a feat.
- Narishma 5y ago
  > Keep in mind that IBM PC/XT had only 640 kB And that's the maximum (without bank switching schemes like EMS). The first version had only 64 KB. There were even plans for a 16 KB version with no disk drive but I don't think it was ever released.
- int_19h 5y ago
  The base model of ZX Spectrum only had 16 Kb, but it was enough for it to run BASIC. And then there's FORTH, which is tiny even in a naive implementation, but can be taken to extremes as well: https://pygmy.utoh.org/3ins4th.html https://pygmy.utoh.org/3ins4th.html
akkartik 5y ago
Assuming you mean static code size, my Mu project currently supports an interpreted Lisp (macros, fewer parens, infix) implemented in a compiled memory-safe low-level language without _any_ C in 450KB. The "runtime library" (mostly in the safe low-level language) requires 120KB. Without unit tests, the binary sizes drop down to 200KB and 30KB respectively, which gives you some sense of the space devoted to tests in each case. As the tests hint, Mu doesn't do anything to try to reduce code size. It's small just by focusing on the essentials. What's left is written for ease of comprehension. (An example of "essentials": Mu still cannot free memory. I run my programs in Qemu with 2GB which seems to suffice.) More details: https://github.com/akkartik/mu https://github.com/akkartik/mu
- agumonkey 5y ago
  the variable/register idea is neat, I always wanted some veneer on top of raw registries.. almost like a cpu monad
- jart 5y ago
  Author here. I assume you're referring to https://github.com/akkartik/mu/blob/main/shell/evaluate.mu https://github.com/akkartik/mu/blob/main/shell/evaluate.mu? It's hard for me to tell, since there's 819k lines of code in Mu according to find . -type f | grep -v '\.git' | xargs wc -l. Does it have lambda and support metacircular evaluation? If not, then why do you think it's LISP-like? If you do nothing to reduce code size, then why do you call it Mu? (I assume by "Mu" you're referring to what UNICODE calls the MICRO SIGN.) 30kb is two orders of a magnitude larger. I don't see how it's relevant to SectorLISP.
  - akkartik 5y ago
    Sorry to tramp over your thread! Mu isn't too related to SectorLISP, I was just responding to the side-discussion about what we can build in under 1MB. To answer your question, evaluate.mu does support lambda (I call it `fn`). My estimates of size were based on `ls -l a.bin` after `./translate shell/*.mu`. I actually didn't really think of the micro interpretation of 'mu' until years after I started the project. The interpretation I had in mind was https://en.wikipedia.org/wiki/Mu_(negative)#%22Unasking%22_the_question https://en.wikipedia.org/wiki/Mu_(negative)#%22Unasking%22_t...
jacquesm 5y ago
I wrote a full CAD/CAM suite for lathe/mill work in a few hundred K, working RAM was another 500K or so...
- agumonkey 5y ago
  Honestly you and people writing similarly small applications should gather and write a book. I don't know if I'm an alien but whenever I see frugal yet non trivial application my brain rejoyces.
  - jacquesm 5y ago
    This was back when 1 MB was considered and amazing amount of memory. It took two years to write this, about 50K lines of high level code and another 10K or so of assembly. Today you would approach such a project in a completely different way, you'd use much more time to make it look pretty and just that part would probably be much larger than the whole package that I wrote. The funny thing is that even so many years later the original software is still in use in some places and there is a whole company centered around that core that has been re-written a couple of times to keep it up to date and to expand its functionality. I highly doubt the present day version would fit in something that small. What's interesting to me is that that old stuff tended to be super productive to work with, zero distractions, just some clearly defined task in a clearly defined environment, if it worked it was bullet proof. No hackers, SaaS, a million connectivity options and no eye candy. Just that one job to be done and done as good as the hardware would allow you to.
    - agumonkey 5y ago
      But that's exactly my point. I think we forgot to aim at super productive, zero distraction, lightweight. And it would be of high educative value to see this sort of work again. Both on the small scale details and the pragmatic value. The sad part to me is that most web apps reenact the same functions but in a css-transition-capable DOM. But functionally I'm not sure you get more.
      - 5y ago
bob29 5y ago
https://www.red-lang.org/p/about.html https://www.red-lang.org/p/about.html Almost as batteries-included as python.
- agumonkey 5y ago
  Ha, I didn't know the whole distribution fit in 1MB. Thanks
- diskzero 5y ago
  I love Red and want to use it more. Sadly my professional life keeps giving me hardware that I can't run it on, so Red is getting marginalized. I wish I had more skill and time to help them out with the 32 to 64-bit transition. [1] [1] https://gitter.im/red/red?at=5e09152cd5a7f357e6a1af83 https://gitter.im/red/red?at=5e09152cd5a7f357e6a1af83

tomcam 5y ago

jart makes me realize that my high school counselor Stella Sawicki was absolutely right when she said I wasn’t living up to my potential

metagame 5y ago
In your defense, Justine's been at this for a long time! Give it time and effort, and you too can do amazing technical things. Potential isn't a concrete thing, it's a set point you can move around. Throw yourself at the computer, and the computer will do interesting things with you, too. If it's not working, go at it from a different angle. Sometimes it's helpful to go back in time to come across things. I'd argue that 90% of cool tech phenomenon arises from studying the past to make something cooler in the future rather than any force of sheer will. A lot of Justine's projects seem to fit this mold (if I remember right she came across the idea for Cosmopolitan after finding that a legacy UNIX feature let you avoid specifying your shell; SectorLISP, McCarthy's metacircular, etcetera). She even cites someone whose entire deal is doing precisely that: Nils M. Holm.
- eggy 5y ago
  Yes, Justine's amazing. I have also been following and reading Nils M. Holm's books. I program in J/APL, and I picked up Nils' book on Klong, but I have not fully worked through it yet. It gives me a perspective on J/APL. His Lisp stuff is great.
  - tluyben2 5y ago
    Nils his works are excellent; I always buy all that come out.
    - eggy 5y ago
      He's very prolific and the content is rich. I always feel I need to step up my game. People like Justine and Nils inspire me to keep at it!

mikewarot 5y ago

I didn't remember an FS register... it was added on the 386, I wonder what would happen if this was run on an old IBM XT? I realize that something had to go in order to fit it in the size limit, compatibility with 8088 CPUs isn't the worst choice. [Edit] Sorry if this sounded too negative... I'm astounded that it's even possible to do this in a sector at all.

adrian_b 5y ago
Intel 8086 and 8088 did not have invalid instruction exceptions. The opcodes that were not documented were either redundant, doing exactly the same thing as other documented opcodes, or they crashed the system. Later, in 1982, 80186 and 80286 introduced invalid opcode exceptions, so starting with the IBM PC/AT any program intended for later CPUs should abort with an error message. Most IBM PC/XT were made with Intel 8088, so the behavior of an 80386 program is unpredictable. Some PC/XT clones were made with 80186 or 80188, or, more frequently, with NEC V20 processors. All these had invalid opcode exceptions, so they should behave like a PC/AT.
jart 5y ago
It's not too negative because to be honest it's something I felt guilty about. It looks we actually have enough room left to fix that, since we're not currently using %bp. We even have room to add the necessary push/pop for %bp to work around a bug in the original IBM PC BIOS implementation. If we make that change, then I've just confirmed with xed -r -isa-set -i sectorlisp.o that's it's pure i8086 and should work. One of us should pull out an old IBM PC and record a video of sectorlisp running on the original hardware. Anyone want to volunteer? I have one but it's difficult for me to use since I only know how to type dvorak.

gavinray 5y ago

Every time I read something by Justine Tunney, I am continually reminded of my mediocrity. I once reached out to them personally to tell them I hope I can be like them when I grow up ;^) On a serious note, this is one of the coolest things I've ever seen. The person mentioned that helped them go from 700 -> 500 bytes, the said "Assembly Heisenberg" appears to be entirely obscure on GH too. Seems like the right set of eyes just happened to find their way to the project at the right time: https://github.com/agreppin https://github.com/agreppin I wish I was born like this.

pmarreck 5y ago
I was already impressed by this person's work when I read about APE (Actually Portable Executable)... Something that should really be a thing IMHO
john-tells-all 5y ago
Agreed, Jart's work is jaw-droppingly incredible, on the order of Fabrice Bellard's achievements. However, I don't see "I wish I was born like this" -- their works encourages me to think and do lots of crazy shit. My previous limitations were just a lack of imagination and creativity. SectorLISP also encourages the "do anything" viewpoint. The original version was published even though way larger than a sector. Other people contributed, sometimes only by publishing a related project (SectorFORTH). By having an idea and publishing something Justine created something unique. Lastly the above page shows the "run program and watch its memory in realtime" technique, which is incredible in itself. The tool is called Blinkenlights https://justine.lol/blinkenlights/ https://justine.lol/blinkenlights/
- jart 5y ago
  It's a nice story about how sometimes the best way to ultimately succeed is to not be afraid to admit when something was tried and failed. By publishing SectorLISP in an unfinished state, I attracted a lot of smart people to the problem. Now that it's complete we can look back and say we did it.

veltas 5y ago

Not really on topic but I found myself looking around this website and this is easily the most interesting personal site I've seen on HN, and then from reading all the angry posts by the right people Justine also seems like the most interesting personality I've seen on here.

gavinray 5y ago
Agreed - As far site content that gets posted. I also like rachelbythebay. But for commenters, there are lots of interesting people.
mark_l_watson 5y ago
I also agree with you. My specialties are machine learning and knowledge graphs, very different than what Justine works on, yet I find digging into her posts fascinating.
- jart 5y ago
  Justine here. I used to work on TensorBoard and I contributed a few hundred thousand lines of changes to TensorFlow. These are my hobby projects so we might not be as dissimilar as you think :-)

pmarreck 5y ago

Does this pass any tests to prove it is a general purpose lisp? (I suppose, writing a lisp evaluator in it might be such a test, but not 100% sure)

akkartik 5y ago

Why is this quoting the top-level lambda expression arguments? Unless I'm mistaken that's not how JMC did it. For example, to define a binding the cited resource http://www.paulgraham.com/rootsoflisp.html http://www.paulgraham.com/rootsoflisp.html uses (defun null (x) (eq x '())) Replacing the defun with an env binding, I believe the value translates to: (lambda (x) (eq x '())) I don't think this should be quoted? Even though lambda isn't typically assumed in the "seven primitives," it _is_ required by the runtime. Are your function calls implicitly dropping quotes when evaluating arguments?

jart 5y ago
Author here. The quotes are indeed needed. Emacs does the same thing. For example: ((lambda (x) (message "%S" x)) (1)) ;; fails: no such function `1' ((lambda (x) (message "%S" x)) (quote (1))) ;; prints (1) The original evaluator is defined so that if the first item of a list, is a list whose first item is LAMBDA, then what it does is it calls Evlis() and Pairlis() which is sort of like a glorified version of Python's zip() function, to attach all the subsequent list items to the parameter name list. ((LAMBDA (ARG1 ARG2 ARG3) <YOUR PROGRAM GOES HERE>) (QUOTE VAL1) (QUOTE VAL2) (QUOTE VAL3)) This is the "venus fly trap" that the blog post mentions. The process of evaluation causes the expression the clamp in on itself where the args get digested into an association list which can be referenced and then the payload is evaluated. This was all non-obvious to me, even after using LISP casually for years, since we normally don't write code that way. Now it's possible to add extra code to the evaluator so that if a naked lambda is encountered, i.e. it sees (LAMBDA ...) rather than ((LAMBDA ...) ...), it just lets it pass through, so you don't need the quotes. We did that originally, but deemed it non-essential and was removed, since that would have made it much harder to hit the 512-byte goal.
- akkartik 5y ago
  By Emacs do you mean Elisp? Your session there is not surprising to me. I don't have emacs handy but what does this do? ((lambda (f) (f)) (lambda() 42)) You might need to throw a 'funcall in there or something, but my hypothesis is that this will work (return 42) without needing the top-level argument to be quoted. 'lambda is a deep special case, basically. I understand that functions always zip through their arguments, evaluating each one. But when you quote the args in the call, I tend to expect the arguments to not be evaluated within 'evlis. I'm surprised that quoting args makes the interpreter smaller! That's pretty interesting. But I think this interpreter will have some behavior that is surprising to anyone used to all extant lisps for examples like this: ((lambda (sym) (cons sym 3)) (quote a)) Here there's no binding for 'a. I expect this to return (a . 3) in JMC's original Lisp.

mastax 5y ago

Was still spooky downloading and executing the same blinkenlights binary on Windows and Linux (WSL). Unfortunately it doesn't actually work in either environment: Error: your CPUID command does not support command 0x80000006 (AMD-style L2 cache information). AMD Ryzen 7 1800X

jart 5y ago
Author here. What are you executing? It works fine on AMD Ryzen for me. That error message doesn't appear in the blinkenlights.com binary. It also doesn't perform that CPUID check. The only place I can find that error message online is for a fizzbuzz codegolf. Perhaps you're confusing sectorlisp with a another project? Also, Blinkenlights should work fine in the Windows 10 Command Prompt. So WSL isn't required but it does run on that too. https://justine.lol/sectorlisp/spooky.png https://justine.lol/sectorlisp/spooky.png
- mastax 5y ago
  Oh, silly me. I hadn't noticed you need the `-t` flag to open the TUI and assumed that since the TUI didn't open that the error was from blinkenlights.
  - jart 5y ago
    Glad I could help. Hope you enjoy Das Blinkenlights. Press '?' for help. Useful shortcuts for controlling execution are 'c', 'C', Ctrl-C, Ctrl-T, and Alt-T. Memory panels can be scrolled with the mouse wheel. You can also zoom in or zoom out the memory display with ctrl mouse wheel, although that might not be available in CMD.EXE and you might need to use something like KiTTY, XTerm, or PuTTY.

Orangeair 5y ago

> According to The History of LISP, the same was true for LISP 1.0. Native integer support was added later as a performance optimization. I feel like this just distills the ethos of LISP so perfectly, I'm gonna use this to explain it to people now.