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2 points by hjek 6 days ago | link | parent | on: Show Arc: Debate (very alpha)

> My idea of graceful degradation is falling back to a message that says "sorry, not going to happen!" :)

Hilarious! A degradation for sure but the graceful part of is questionable.

3 points by i4cu 6 days ago | link | parent | on: Show Arc: Debate (very alpha)

Obviously you're more into graceful degradation than progressive enhancement.

My idea of graceful degradation is falling back to a message that says "sorry, not going to happen!" :)

So, obviously, I'm more into progressive enhancement than graceful degradation.

> ClojureScript looks promising though...

Well to be fair, ClojureScript is not a full fledged framework; It is a framework, but really it's more of a compiler with some library functions. Reagent [1], for example, is a library that bridges the gap between ClojureScript and React. So I'm not sure it's fair to compare ClojureScript to these full fledged frameworks... you're still correct though, in that ClojureScript alone can produce apps with a smaller footprint.

That said & just to compare, last time I checked, React and Elm are appx. 42-45kb, Angular is 90kb. So HN search, obviously need to add their own code to bring it in at 1.19M.

My app, written in pure Clojurescript, is currently at 90kb minified. I hope to bring that down, but chances are the first release will actually be a little larger.

1. https://reagent-project.github.io/

3 points by hjek 6 days ago | link | parent | on: Show Arc: Debate (very alpha)

> Well progressive enhancement is not, not using JS. Progressive Enhancement is pretty much the opposite of Graceful Degradation.

Yea, exactly. I'm OK with JavaScript being used for better UX as long as core functionality works w/o JS. From W3C:

> So, graceful degradation is the practice of building your web functionality so that it provides a certain level of user experience in more modern browsers, but it will also degrade gracefully to a lower level of user in experience in older browsers. This lower level is not as nice to use for your site visitors, but it does still provide them with the basic functionality that they came to your site to use; things do not break for them.[0]

If it is assumed that voting is part of the basic functionality of HN, then HN does PE wrong by breaking it when there's no JS. It's a relatively recent change to HN and Anarki doesn't suffer from that issue.

Yet it's neat that HN uses JS to prevent page reloading on voting. I'm just doing no JS at all on my own project here to make sure I don't accidentally rely on it, because I don't really trust myself to use it in moderation.

> Frameworks can help with all this, but it's at a cost. The file size is bigger,

Yea, they're beneficial, but heavy. HN front page: 62K. HN search: 1.19M. Did they really need Angular for that search input form? That's where ClojureScript looks promising though: Their `helloworld` example is just 20K.[1]

[0]: https://www.w3.org/wiki/Graceful_degradation_versus_progress...

[1]: https://clojurescript.org/guides/quick-start

3 points by i4cu 10 days ago | link | parent | on: Show Arc: Debate (very alpha)

> I read a blog post[0] about Wagtail,....because it's more like a CMS framework...

Yeah neither Drupal nor Wagtail sound remotely appealing to me. A CMS, in general terms, is just that: a Content Management System. Now that's pretty broad with lots of room for products which are both good and bad.

Personally I'm interested in the Business Intelligence space where people build Apps, only I'm targeting companies who wish to empower their Business Analysts (or specifically the blue to 'purple people') to build apps and streamline inefficient IT processes.

I'm not sure if BI apps are considered a CMS or not, but when I read that 'trap' article I couldn't help but relate.

> I think I'm just really pro progressive enhancement, and it's sometimes the first thing to go.

Well progressive enhancement is not, not using JS.

Progressive Enhancement is pretty much the opposite of Graceful Degradation. In GD you fallback to allow lesser technologies to handle the workload, where PE is starting with limited functionality and build up incrementally to gracefully handle the workload. JS is often what is used to achieve PE.

> I think there's a bit of a tendency to use way too large and slow JS frameworks, but I'm interested in ClojureScript now because it seems to be all about eliminating dead code and optimizing.

Yep.

All I can say here is that automation and the benefits that comes from that will have a cost. Your product/app/page will contain larger files which do some amount of work for you.

Developers have a tendency to see 'frameworks' from a maximal code efficiency perspective, but frameworks really are all about lessening the $ cost, the work burden, time to market and the operational maintenance. The argument is always "If you're building a blog you shouldn't need a framework." And that's true, but most frameworks are not built for making blogs, they're built for greater things - however if said framework makes it easier for person A to do thing X, even if it's just a blog then, really, it's hard not to see it happening (even though developers don't like to see it).

Frameworks, really, are for when large tailor made products become nightmares to manage, that's when they become the go to "solution" and start to shine. Modern day web development has a lot of pitfalls and will require a skillset that not everyone has. Not everyone can make dynamic apps that don't get bogged down by limiting factors like the DOM tree (cluster fuck), rendering/paint (bottle-necks), and single threaded environments (the async data gotcha's). Frameworks can help with all this, but it's at a cost. The file size is bigger, it's not Free Software, it uses JS and you have the potential to be caught-up in a CMS trap.

3 points by hjek 10 days ago | link | parent | on: Show Arc: Debate (very alpha)

> I've only had to time to take quick look, but I'm impressed at how clean the code looks.

Good to know that it's somewhat readable for people who are not me!

> I could be wrong, but it actually looks smaller in size than Arc's version, but with more features.

It's still smaller and it does have file upload, but there's a lot of news.arc features missing before this one is usable.

> > not a general purpose cms (link to 'The CMS Trap')

> That's me. I'm that guy - lol (well not quite but close).

I read a blog post[0] about Wagtail, a Python CMS, and wanted to try it out. Once up and running, it has a user login/registration form, but you literally can't post anything, because it's more like a CMS framework or something (or maybe that is what CMS really means?). To me that embodied 'The CMS trap'.

> Between, no JS, Free Software and the above I'm getting that you and I have very different goals :)

Yea, good to hear different opinions here.

Ok, so I'm not totally against JS, and I'm using it myself for other stuff. I think I'm just really pro progressive enhancement, and it's sometimes the first thing to go. For example, I don't think HN has a reason to not allow voting w/o JS. I think there's a bit of a tendency to use way too large and slow JS frameworks, but I'm interested in ClojureScript now because it seems to be all about eliminating dead code and optimizing.

[0] https://torchbox.com/blog/torchbox-has-dropped-drupal/


> I'm trying to make something I think the world needs, and I'm trying to make the case for something the world hasn't considered to be a good idea yet. I'm sure I don't have all the details nailed down yet :)

"To boldy go where no man has gone before"

"Second star on the Left"

I can get behind that :)


Thanks for the probing questions! Yes, I don't mean to move the goalposts on my reasons. I feel like I'm reaching for something fundamental that could end up having lots of different benefits, mostly things I can't anticipate.

I don't actually care that much what the high level language is at the top. I'm biased toward Lisp :) so that's what I'm going to build towards. But if others want a different language I want to make it easy to switch the superficial syntax to suit their taste -- and convert all existing code on the stack so everything is consistent and easy to read. If some others want to add new runtime features, I want to make that easy too. Finally, I want it to be tractable to mix and match syntax and runtime features from different people and still end up with something consistent. Using tests at the bottom-most layers, and building more rigorous type systems and formalisms as necessary higher up.

The key that would make this (and much else) possible is making the global structure of the codebase easier to comprehend so that others can take it in new directions and add expertise I won't ever gain by myself, in a way that I and others can learn from.

Ignore the other prototypes in this repo; they're just details. The goal I'm working toward is a single coherent stack that is easy for others to comprehend and modify.

This isn't a product, in the sense that I can't/won't charge money for it. I'm not really making something others want right now. I'm trying to make something I think the world needs, and I'm trying to make the case for something the world hasn't considered to be a good idea yet. I'm sure I don't have all the details nailed down yet :)

3 points by i4cu 10 days ago | link | parent | on: Show Arc: Debate (very alpha)

Kudos, it looks good. I've only had to time to take quick look, but I'm impressed at how clean the code looks. I see a lot of arcish code so it's made it easy for me to interpret.

I could be wrong, but it actually looks smaller in size than Arc's version, but with more features. Maybe that's due to Racket lending functionality and adding DB code that makes it straight forward.

> not a general purpose cms (link to 'The CMS Trap')

That's me. I'm that guy - lol (well not quite but close).

Between, no JS, Free Software and the above I'm getting that you and I have very different goals :)


> Basically, I want to commoditize the equivalent of a Lisp Machine for any language. My goal is to help people collaborate across incompatible forks...

I'm struggling to understand so forgive me, but the reasons why and what you're doing seem to change or at least are many fold and thus hard to unpack. Or maybe the different prototypes are messing me up.

So let me see if I can unpack it (at least for myself :)

Your goals are:

1. To build prototype 'x' compiler/language that's more robust and easier to maintain because it has been built with testing capabilities in mind (I'm imagining a model with convenience features or set requirements to accomplish this).

2. Build prototype 'x' to permit developers to build their own compiler/language(s) that inherit the benefits from prototype 'x', thus making that process more enjoyable and more likely to succeed.

3. Permit/Encourage greater collaboration amongst developers, on separate prototype 'x' projects, because prototype 'x' is robust and developers are working under a shared model that has core concepts/features that act as a bridge for that collaboration to happen.

Does this seem right?

So is this a project that you're doing because you're passionate about it and you think it can change things (i.e. improve the lives of other people)? Or is this a product idea where you have assessed there's a need and you're going to fill it?


> I'd make a top-level dir called 'prototypes'... and then branch down.

Yeah, I've been planning a reorganization like that. Unfortunately the reorg is going to break all the links I shared before I thought of this :/ So I'm going to wait a bit before I make the switch.

> if you can build a language that allows someone to build arc and even a clojure version of arc using the same base code, that would be cool.

I'm not aiming quite there. That would be really hard to do, and then it would be impossible to keep in sync with existing language upstreams over time, given the underlying platform will be very different. The way I imagine providing something similar is this: there would be multiple forks of the Mu stack for providing a Clojure-like or Arc-like high-level language. But these languages wouldn't be drop-in replacements for real Arc or real Clojure. Also, each fork would try to minimize the number of languages it relies on to do its work, so you wouldn't immediately be able to run both Clojure and Arc on a single stack. Because every new language used in a codebase multiplies the comprehension load for readers. (I ranted about this before at https://lobste.rs/s/mdmcdi/little_languages_by_jon_bentley_1...)

Basically, I want to commoditize the equivalent of a Lisp Machine for any language. My goal is to help people collaborate across incompatible forks, _but_ the forks have to all have certain characteristics that no existing software has (because it all assumes rigid compatibility requirements).


Thanks for trying them out!

Those examples expect arguments at the commandline, and I chose not to perform error checking for an example :) The focus lay elsewhere for them. See the comment at the top for each.

ex11.subx is running a test for each of those dots :)


Ah... OK.

See I always move up to the top level directory and work my way down. So as I did this my reference point for understanding got completely mixed up.

I'd make a top-level dir called 'prototypes' with details like [1] you provided in this comment and then branch down.

* Also, I'd probably limit referencing Mu, specifically, in SubX. I don't think its helpful. Just remove this line:

  "We'll gradually port ideas for other syscalls from the old Mu VM in the parent 
  directory."
  
It doesn't add much value and takes people's attention away as they start trying and understand the relationship. If you need to just add notes at the bottom.

[1] "The hope is to one day build a robust, hackable stack culminating in a high-level Lisp atop this infrastructure, a stack that leans into the Lisp tendency to fragment dialects by encouraging people to create incompatible forks -- while also making it easy (but not automatic!) to share code between the incompatible forks."

Re: [1]

Yeah, if you can build a language that allows someone to build arc and even a clojure version of arc using the same base code, that would be cool. I'd immediately try spinning up a new version of arc with clojure's tables and table functions :)


Yea, I think that's more inviting.

I got to try out the point of compiling and trying out your programs now. `ex8`, `ex9` and `ex10` all segfault here.

Some time ago I was at a wedding, and I was terribly bored, until I found out that the guy to my left was writing washing machine software in assembly. In a way it seems awfully primitive, e.g. your `ex11.subx` is 350 lines long and prints out `.......` but I guess in certain systems it's the only option, and what's underneath it all in any system.


I might just be outside the target audience, for now. I don't even know any C. Realistically, I think it would have to be spoon-fed to me in some Bret Victor-esque crocodiles and eggs[0] manner for me to not lose focus.

I went through this absolutely fantastic SQL tutorial this week. Perhaps you might find their list of pedagogical principles[1] useful?

I think one thing that potentially could tempt me into low-level code would be making cool tunes[2][3].

[0]: http://worrydream.com/AlligatorEggs/

[1]: https://selectstarsql.com/frontmatter.html

[2]: https://www.youtube.com/watch?v=GtQdIYUtAHg

[3]: https://www.youtube.com/watch?v=qlrs2Vorw2Y


I just made some tweaks to the Readme. What do you think?

https://github.com/akkartik/mu/commit/4650c8188f

https://github.com/akkartik/mu/blob/master/subx/Readme.md

2 points by hjek 11 days ago | link | parent | on: Show Arc: Debate (very alpha)

> 2. Are you building a file transfer service? Or are you imagining that people will want to share files on a HN-like website? I'm not sure why that would be a common use case.

File upload wouldn't make sense on HN, Arc Forum or Lobsters, and I get that it's entirely on purpose that it's not present on those sites.

But I've been hosting a News site, and those of my friends who use it often submit links to something they've put on Dropbox or Google Drive, so I'm simply observing that this use case is present and that file upload is missing on my site. Perhaps it's because it's a different type of exchanges: a guitarist uploading a recording of a Charlie Parker solo, an artist uploading a drawing, etc.

Well, perhaps I should be using $CRAPPY_PHP_CMS_WITH_FILE_UPLOAD instead of News, but why can't I have well-structured content and file uploads at the same time?

It's also about future extensibility, ways of presenting these file uploads that I haven't thought about yet. I do occasionally write PHP for money. I don't have a very high opinion of that language, and I'd rather make something from scratch in Racket than write it as a Drupal plugin. Given the relative quantities of Drupal plugins and Racket web apps, that might be an unpopular opinion, but it shouldn't seem too strange on this forum. I'd prefer to make custom interactive web sites by extending a code base in Racket rather than PHP.

It's actually also for the use-case of being off-the-grid, yet needing to send/receive files to people in the same room, but not being able to find a USB stick. That situation happens surprisingly often for me. A zero-config web app is useful here because everyone have a browser on their computer (whereas not everyone have FTP / SSH / SMB).

> 1. Are you trying to build an RSS reader? Or do you want to support RSS versions of pages on your site?

I plan to do both. Building a social RSS reader integrated in a News-like app. And this News-like app would provide RSS feeds in the same way Anarki does. I image it wouldn't be too difficult.

2 points by akkartik 11 days ago | link | parent | on: Show Arc: Debate (very alpha)

I'm wondering:

1. Are you trying to build an RSS reader? Or do you want to support RSS versions of pages on your site?

2. Are you building a file transfer service? Or are you imagining that people will want to share files on a HN-like website? I'm not sure why that would be a common use case.

3 points by hjek 11 days ago | link | parent | on: Show Arc: Debate (very alpha)

> What parts/features do you want to take from each, and why do you think they should coexist in a single product?

DropBox/WeTransfer/Google Drive/OneDrive is just what people use to send larger files. I'm not a fan of those sites, but I have observed that people I know find Filezilla and FTP very intimidating. There's some other free apps for this, but either they're in PHP or they're too complicated to install or use or hack on. Droopy[0] works good for this, so as a start I just cloned what Droopy does; just to check whether Racket/SQLite is fast enough for this use case. (It is)

I like RSS as an idea and the fact that most sites have RSS feeds, but I think it's underappreciated by non-techies, who think that Facebook or Twitter are the only place you can "follow" stuff. For friends of mine to even consider using RSS for anything, I think it needs to be more accessible. I use Newsbeuter for reading RSS but I would never recommend it to non-techie friends, and it has some annoying bugs: Sometimes text is missing, podcast download is flaky at best so I have to copy the url out at get it with curl, and the interface becomes unresponsive when there's many feed items. So I'm thinking of giving it a try to make a web-based RSS reader that encourages sharing and that at very least I'd enjoy using myself. I think this would fit naturally with a News-style app, basically just having RSS feed items being shown alongside other people's posts, but perhaps tweaking the ranking in a way that external feeds don't overshadow local content (assuming that external feed items are votable). Some non-techies have shown me the Feedly app, which (I think) uses RSS, and (I presume) has some kind of social recommendation system, so I just think it would be nice with a free/libre web app doing something similar.

Then, the HN/Lobsters part is basically about having a minimalist web forum with tree structure replies and well thought out ranking algorithms and spam handling, instead of this thoughtless phpBB-style newest-first unstructured mess. One thing Lobsters does right here is that it notifies you when someone replies to a comment of yours. On HN it's possible for someone to reply and you just won't notice because it's so deeply buried in old threads. But I like all the different ways you can sort/view the content on HN.

Also, I've had some painful episodes trying to back up Wordpress sites. It's not pleasant, because there's little distinction between code and content which is stored in a mish-mash of database entries and folders. WP barfs all over the disk. That's something HN does right, because all the content is in the `www` folder. But, then file upload to HN is not really a realistic thing.

So I'm just trying to mix-and-match things I like from different software. A lot of ideas. Haven't gotten far yet! But I guess it's ok to share work-in-progress here.

If I didn't have dockerphobia and mild JS-intolerance, I'd probably just be running Mastodon or something.

[0]: https://github.com/stackp/Droopy/issues?q=is%3Aissue+is%3Acl...


That's a good point. I have similar instructions here, but they're in the second section, 3 screens down..

The audience is assembly-curious programmers, but you aren't expected to know any assembly. I just want to try to hook anyone interested in the goal. If you're interested in a stack you can understand from the ground up, I'm willing to try to explain things to you.


I read the first section of the readme without really understanding much but also not expecting to as I don't know x86 assembly. Then I decided to at least give the examples a superficial look as I'd noticed the word newcomers in the readme. But I couldn't see the number `42` in a program meant to print `42`, so that's where I gave up.

Is this meant to be a tutorial for assembly noobs?

For comparison I think your readme for Wart[0] is more welcoming: Briefly explaining what it is and how to run it, and then straight onto a simple example that people can actually try out.

[0]: https://github.com/akkartik/wart

2 points by akkartik 11 days ago | link | parent | on: Show Arc: Debate (very alpha)

Very cool. Can you elaborate on this tantalizing sentence?

> My goal is to make a simple hybrid of HN/Lobsters and Feedly/Google Reader and DropBox/WeTransfer/Google Drive/OneDrive.

What parts/features do you want to take from each, and why do you think they should coexist in a single product?


Absolutely valid criticism. I'd love to hear more about what you did between seeing the link here and navigating to that example program. I've been trying to build a path to gradually take programmers to an understanding of (this particular unconventional style of) assembly programming. For example, I'm curious how much of the Readme you read, and if you happened to notice that the Readme has an orientation on the x86 processor.

I also made a couple of tweaks to this particular example. I hadn't looked at it in a while. Thank you! https://github.com/akkartik/mu/commit/d6535f3382


Thanks for the questions! Part of the problem is that the repository isn't for a single 'language'. It's for my experiments for a new way to program that makes codebases easier to understand. As the biggest stress test for the new way, I've trying to create a whole stack that is easy to understand. But it's just a prototype, or rather a series of prototypes. I've tried to make each prototype self-contained, with a Readme and instructions for running it that will continue to work to this day.

Prototype 1 was a statement-oriented Assembly-like language built in Arc. You can still see it at https://github.com/akkartik/mu/tree/master/arc. I worked on it until about 2015. It's 3kLoC of code and 7kLoC of tests. The most substantial program I built in it was a hacky Lisp repl with syntax highlighting: https://github.com/akkartik/mu/blob/master/arc/color-repl.mu

Prototype 2 was a similar (but not compatible) language built in C++. It had the most work on it, and I also used it for teaching for a couple of years. I stopped working on it sometime this year. It's still available on the top level at https://github.com/akkartik/mu. It's 23kLoC of C code, and 5kLoC of Mu libraries. The most substantial program built in it was a 2-pane programming environment I used for teaching programming: https://github.com/akkartik/mu/tree/master/edit#readme. It's 12k lines of Mu code, about half of which is tests. You can see its sources colorized to be easier to read at the bottom of http://akkartik.github.io/mu.

Now I'm at prototype 3, SubX. It's in a very preliminary state. As above it is not intended to be compatible with existing prototypes. The previous prototypes were kinda-sorta designed to be easy to translate to native code, but they were still simple-minded tree-walking interpreters. I had hazy plans of gradually compiling them to native code from the top down, but that turns out to be beyond my ability. SubX starts from the bottom up, building an almost trivial syntax on top of raw native x86 machine code, and I'm gradually learning how to implement a compiler in it. Most people would say it's too hard to build a compiler in assembly these days when we have so many high level languages available. I'd like to see if it's manageable with the right framework for writing automated tests. So SubX starts out not with improvements to syntax, but to error checking and automated testing.

The most substantial program I've built in SubX so far is a port of the very initial version of Crenshaw's "Let's build a compiler" series[0]. All it does is read a number and emit native code to return that number in the exit status: http://akkartik.github.io/mu/html/subx/apps/crenshaw2-1.subx.... So SubX is still in a very early state.

SubX tests aren't inside the functions they test, they're just interleaved in the same file. Any label that doesn't start with '$' is the start of a new function. Functions that start with 'test-' are tests, and they all run when you run with a 'test' argument on the commandline.

The hope is to one day build a robust, hackable stack culminating in a high-level Lisp atop this infrastructure, a stack that leans into the Lisp tendency to fragment dialects by encouraging people to create incompatible forks -- while also making it easy (but not automatic!) to share code between the incompatible forks. It would still be some amount of work to copy the tests over and then make them pass, copying over bits of code at a time and modifying it as necessary. That's the sort of workflow I want to encourage rather than blindly upgrading software by running a package manager command. But before I can recommend it to others I have to see if I can get it to work. This repo is a test bed for eventually building tools to help people collaborate across incompatible forks.

Thanks for asking these questions! They're very helpful in understanding how others see the mess my repo has turned into. I'm going to try cleaning it up.

[0] https://compilers.iecc.com/crenshaw


I'm somewhat disoriented by the very first example[0]. How is a newcomer meant to grok how this program prints out 42?

    bb/copy-to-EBX  2a/imm32
    # exit(EBX)
    b8/copy-to-EAX  1/imm32
    cd/syscall 0x80/imm8
This is not meant to criticize, but just as feedback from a real assembly newcomer, since this is in your project description:

> It would make it easier to write programs that can be easily understood by newcomers.

[0]: https://github.com/akkartik/mu/blob/master/subx/examples/ex1...

3 points by hjek 11 days ago | link | parent | on: Show Arc: Debate (very alpha)

This is what's happening with my "I'm gonna rewrite News in Racket so I can get fast file uploads"-project. I settled on SQLite instead of Datalog, because SQLite is fast.

The score of an item is derived from the votes, not just a stored number. This should make `unvote` easy to implement.

Also, user text input is not forgotten, so there's no need for `unmarkdown`. (However I'm not claiming that my markdown implementation is appropriate)

Comment tree is displayed as list of lists, so folding should be easy to implement.


I'm going to ask some seriously basic questions here:

1. So, Mu is a general programming language - right? (in reading the docs I almost wondered if it was a testing language only).

2. It is built on top of Arc - right? (It looks as though it's built with c code, but I see arc in there too so I have to wonder where it fits in).

3. Is the idea that you build your tests for each function inside the actual function? (which the examples seem to illustrate). If that's the case wouldn't the code become really large and hard to navigate? Have you written any substantial programs in it to see how that might look?

4. How does SubX relate to Mu?

I'm probably missing the depth being presented here, but I'm a high-level language guy so I have to start with basic questions :)

4 points by i4cu 13 days ago | link | parent | on: Ask: When to use lists vs tables?

It's probably worth reading the arc tutorial [1].

I mention it because pg makes a fairly good point about using alists.

  "There is a tradition in Lisp going back to McCarthy's 1960 paper [2] 
  of using lists to represent key/value pairs:

  arc> (= codes '(("Boston" bos) ("Paris" cdg) ("San Francisco" sfo)))
  (("Boston" bos) ("Paris" cdg) ("San Francisco" sfo))

  This is called an association list, or alist for short.  I once
  thought alists were just a hack, but there are many things you can
  do with them that you can't do with hash tables, including sort
  them, build them up incrementally in recursive functions, have
  several that share the same tail, and preserve old values"
Of course none of this negates anything in akkartik's response. I just think there are some helpful tips in the tutorial.

1. http://www.arclanguage.org/tut.txt

2 points by akkartik 13 days ago | link | parent | on: Ask: When to use lists vs tables?

You got me, I was careful to use the word 'natural' in the first paragraph but I forgot to do so in the second ^_^
3 points by krapp 13 days ago | link | parent | on: Ask: When to use lists vs tables?

>But the one thing they can't do is represent code and trees in general. That's where cons cells come in.

They can if you can nest them, or include references to other keys (like foreign keys in SQL or something) It's inefficient but it's possible. You can even represent trees in a flat array if you work hard enough.

Although maybe I should be pedantic and clarify that you can represent trees with tables but not in tables natively, of course.

4 points by akkartik 14 days ago | link | parent | on: Ask: When to use lists vs tables?

Lists are easy to split and merge, insert and delete nodes from, but searching them is slow. Tables are fast for searching and insertion and deletion, but they don't naturally encode ordering relationships.

Check out this chapter: http://www.gigamonkeys.com/book/they-called-it-lisp-for-a-re... Tables are often great for things Lisp historically used lists for. But the one thing they can't do is represent code and trees in general. That's where cons cells come in.

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