Wow, perhaps I should become an APL programmer. (My links below are probably familiar to everyone here, so forgive the shameless replugs. I'm mostly just working through commonalities for my own self.)
"[There is] a sharp contrast between Subordination of Detail and Abstraction as the term is commonly used in Computer Science. Iverson’s notion of subordination is the elimination of notational obligations through the use of generalization, systematic extension, and implicit guarantees. The usual notion of abstraction is the means by which 'API' barriers may be introduced to implement conceptual frameworks that suppress underlying implementation considerations in order to allow a black box reasoning at a different, non-native abstraction level."
I'm very partial to this point, but confusingly I've been calling Iverson's notion of subordination of detail "abstraction", and Iverson's notion of abstraction "service"  or "division of labor" . Though lately I try to avoid the term "abstraction" entirely. That seems on the right track.
Regardless of terminology, this is a critical distinction.
"Common practice encourages decomposing a problem into very small components, and most programming languages emphasize a clear picture of a small piece of code in isolation. APL emphasizes finding ways of expressing solutions around the macro-view of the problem."
Quoting Knuth: *"I also must confess to a strong bias against the fashion for reusable code. To me, re-editable code is much, much better than an untouchable black box or toolkit."
Compare me: "Watch out for the warm fuzzies triggered by the word 'reuse'. A world of reuse is a world of promiscuity, with pieces of code connecting up wantonly with each other. Division of labor is a relationship not to be gotten into lightly. It requires knowing what guarantees you need, and what guarantees the counterparty provides. And you can't know what guarantees you need from a subsystem you don't understand."
OMG, he's talking about "big picture" and "optimizing for the rewrite" I call the latter rewrite-friendliness at http://akkartik.name/about. And "big picture" is in the navbar on the right of my side.
Ok, that's enough replugging. The most tantalizing idea for me here is to try to get structure to do some of the heavy lifting that names do in more conventional languages.
As I remember, brevity was one of PG's goals in creating Arc. That thought came to mind as I was reading this article.
I haven't engaged in APL programming but I have done some in other array languages (Klong, J and Q'Nial) and the practice has been enjoyable, not only in getting the answer but also in learning a new way to think/twist one's mind.
Not at all. I meant that if your server doesn't serve much traffic it'll spend much of its time inside serve-socket blocked on a new connection. It's only after serving a connection that it'll loop around to check quitsrv.
I just ran an experiment, and indeed the server stops after one more request:
ready to serve port 8080
arc> (= quitsrv* t)
; now browse to localhost:8080; page served
quit server ; printed by *serve*
; hit reload on localhost:8080; no response
Thank you for your help!! Could you help me understand what you'd like me to do?
I'm not sure what you think I should try.
After looking up the definition of the 'until' macro, the line of code referenced seems to tell me: if quitsrv* is not nil, then continue to serve-socket, which looks to me, at a noobie's glance, as returning the function "accept-request-with-deadline", opening up threads to serve the request?
i.e., quitsrv* now returns t. According to this definition, doesn't that mean that serve-socket should stop?
And incidentally, when I run more defop macro calls, it returns the 'procedure' but (asv) doesn't work; none of the new page on localhost show up (instead it is "Unknown"). I'll look more into it but not really sure how to proceed after glancing at (def asv).
I've copied down the definitions for while and whilet from arc.arc but they don't seem helpful at first glance. Will look further into them if you think it would be useful.
Not a dumb question at all; there may well be something broken here.
It'll be a few hours before I can try running it, but one possibility: perhaps it will quit after serving one further request? Looking at the code (https://github.com/arclanguage/anarki/blob/3a07f946f9/lib/sr...) I think it's waiting on serve-socket before it gets around to checking quitsrv again. Can you try that if you haven't already?
I tinkered with Anarki a whole bunch and finally got this working smoothly. There was a missing step, because it turns out we need to load certain Racket-side bindings into a namespace in order to be able to evaluate Arc code there. It seems more obvious in hindsight. :)
I approached this with the secondary goal of letting a Racket program (or a determined Arc program) instantiate multiple independent intances of Anarki. The ac.rkt module was the only place we were performing side effects when a Racket module was visited, and Racket's caching of modules makes it hard to repeat those side effects on demand, so I moved most of them into a procedure called `anarki-init`.
By adding one line to the example I gave...
(let my-ns (nsobj)
; Load the Arc builtins into the namespace so we can evaluate
(w/current-ns my-ns ($.anarki-init))
...it becomes possible to evaluate Arc code in that namespace, and the example works.
Before I started on that, I did a bunch of cleanup to get the Anarki unit tests and entrypoints running smoothly on all our CI platforms. To get started on this cleanup, I had a few questions hjek and akkartik were able to discuss with me on issue #94: https://github.com/arclanguage/anarki/issues/94
A lot of the problems I'm fixing here are ones I created, so it's a little embarrassing. :) It's nice to finally put in some of this missing work, though. I want to say thanks to shader and hjek for talking about modules and packages, provoking me to work on this stuff!
I've recently discovered the Caddy server (https://caddyserver.com/), which makes SSL and application proxy deployments super easy. Like, 2 lines of config:
domain.com #uses the domain to automatically set up SSL with Let's Encrypt
proxy / localhost:8080 #redirect everything to Arc on 8080
I will say that Arc runs a bit resource intensive, and the slightly slow boot times mean you don't want it to have to re-launch because of infrequent requests. I don't know how well it would work on Heroku.
Also, some VPS services like vultr.com offer $5/mo nodes that have more resources than what you get from Heroku at $7/mo anyway.
It looks like I might've subtly broken ns.arc with my own changes to make Anarki installable as a Racket package. Here's an example that should be working, but currently isn't:
(= n 2)
(= my-definition (* n n))
(let my-ns (nsobj)
; Populate the namespace with the current namespace's bindings.
(each k (ns-keys current-ns)
; Racket has a variable called _ that raises an error when
; used as an expression, and it looks like an Arc variable, so
; we skip it. This is a hack. Maybe it's time to change how
; the Arc namespace works. On the other hand, copying
; namespaces in this naive way is prone to this kind of
; problem, so perhaps it's this technique that should be
(unless (is k '||)
(= my-ns.k current-ns.k)))
; Load the file.
(w/current-ns my-ns (load "my-file.arc"))
; Get the specific things you want out of the namespace.
cannot reference an identifier before its definition
in module: "/home/nia/mine/drive/repo/mine/prog/repo/not-mine/anarki/ac.rkt"
The idea is, you create an empty Arc namespace with (nsobj), you use `w/current-ns` to load a file into it, and you use `a!b` or `a.b` syntax to manipulate individual entries.
An "Arc namespace" is just a convenience wrapper over a Racket namespace that automatically converts between Arc variables `foo` and their corresponding Racket variables `_foo`.
For some overall background...
I wrote ns.arc when I didn't have much idea what Racket namespaces or modules could do, but I was at least sure that changing the compiled Arc code to more seamlessly interact with Racket's `current-namespace` would open up ways to load Arc libraries without them clobbering each other. It wouldn't be perfect because of things like unhygienic macros, but it seemed like a step in the right direction.
I went a little overboard with the idea that Racket namespaces and Racket modules could be manipulated like Arc tables. However, that was the only clear vision I had when I embarked on writing the ns.arc library, so I approximated it as well as I could anyway. In fact, I don't think the utilities for generating first-class modules (like `simple-mod` and `make-modecule`) are all that useful, because as I understand a little better now, Racket modules are as complicated as they are mainly to support separate compilation, so generating them at run time doesn't make much sense.
I'm still finding out new things about what these can do, though. Something I didn't piece together until just now was that Racket has a Racket has a `current-module-name-resolver` parameter which can let you run arbitrary code in response to a top-level (require ...) form. I presume this would let you keep track of all the modules required this way so you can `namespace-attach-module` them to another namespace later. Using this, the kind of hackish partial-namespace-copying technique I illustrate above can probably be made into something pretty robust after all, as long as Anarki sets `current-module-name-resolver` to something specific and no other code ever changes it. :-p
> Were you thinking a mobile friendly web app, or trying to run it natively on a phone?
The java/js ecosystem has the largest reach making it the easy choice. One could work on a js compiler and target pouchDB as a starting point. That said choosing js also makes Arc go further down the path Clojure has already gone putting the two closer together, and with Clojure being so far ahead in that arena then maybe it's doomed to fail. The other way to go is to do what Clojure is not great at. iOS development? maybe integration with swift? At any rate I'm not a language development guy. I can only tell you what would appeal to me. I mostly use Clojure and a really easy to use arc->iOS app development ecosystem would be really cool.
> Without the ability to share code easily, it's a lot harder to build on and benefit from community effort.
I've just been dumping my Arc experiments into the Anarki repository. Akkartik manages it by the policy that pretty much anyone can commit anything, so I haven't had any issues sharing my code. I've recently put a Puredata compiler in Arc in there, https://github.com/arclanguage/anarki/blob/master/lib/pd.arc
The interactive help in Anarki is great, although there are some undocumented functions. A great improvement, which would be very easy to implement, would be to add the documentation from the various Arc sites to the Anarki interactive help.
It's just insane that Arc Forum doesn't encrypt HTTP but, well, as you write, we can't change Arc Forum. Maybe they'll update it some day, or someone will set up an unofficial one that's more up to date?
It looks quite humble but it has both a repl and an interface for saving/running various web apps.
I've set it to be enabled by default in Anarki. And it's only available for admins, because it can run system commands. I wonder if it would be possible to allow any user to develop apps securely, e.g. by disabling unsafe commands or sandboxing it somehow? Perhaps there is a simple way of doing that? It could open Arc web app development up to any user of an Anarki driven page.
I think those features mentioned above still need better documentation, too.
Other HN features that Anarki News is lacking:
* hide item
* past front pages
* show all stories from same site by clicking on domain name
Maybe we should emphasize the flexibility of our language designs by making the language itself more modular. It would be challenging from a compatibility/dependency standpoint, but those are problems we might have to solve anyway. It would help to have better isolation of components.
> I don't have a short-term answer for how to solve Arc's users-vs-libraries chicken-and-egg problem ^_^
Be the change you want to see in the world... I'm not really sure how to motivate the community, but I am rather attached to it, even if I have been a very infrequent lurker over the past years. We have had a relatively high amount of discussion over the past few days though...
I don't think we can just expect to flip a switch and suddenly get a community; we have to /be/ a community, and then people might be willing to join us.
> exploratory programming with a tool that can't provide basic functionality will limit how much you can explore
Absolutely true, which is why I do think the Racket integration is important, so we can just wrap its many and powerful libraries in lighter-weight arc libs, and also why I think a decent package system is important. It needs to be easy to share code, and to find solutions to problems. Otherwise everyone spends too much time rebuilding the same wheels.
> features like db integration bring users
Absolutely. I think better db support in arc would be awesome to have. Especially if we can build an ecosystem where "intelligent defaults" are the norm, so that 90% of the time the exploratory developer can get a db up and running with 1-2 lines.
> todo list mobile app with local db in 30 lines of code
An admirable goal. That's actually a great idea of something we could work toward as a community project, each building pieces that eventually come together to make a decent modern app.
Hmm, I don't think pg has abandoned Arc. And I don't think maintaining compatibility is a concern even so. So far Arc has made no compatibility guarantees. We're all forking pre-alpha software. So it's conceivable the hundred-year language will have features from Anarki. Forks that restrict where they get good ideas from will be outcompeted by forks that don't.
Though lately I consider it more likely that a hundred-year language will have a leveled-up conception of "compatiblity", one that assumes orders of magnitude more forking activity. (See "the Zen of Mu" at the bottom of http://akkartik.github.io/mu; Mu is my attempt at building out the foundations for a hundred-year stack. With, perchance, something like Arc on top.) Perhaps Arc shouldn't be a single language but a family of forks (https://lobste.rs/s/n0d3qo#c_rue8pf). Not a single tree but a clonal colony (https://en.wikipedia.org/wiki/List_of_longest-living_organis...). That'll only work if we can make it easy for superficially-incompatible forks to exchange features and functionality back and forth. Which is an unsolved problem so far. So we may well be very far from a hundred-year language.
Anyways, this tangent is my contribution. I don't have a short-term answer for how to solve Arc's users-vs-libraries chicken-and-egg problem ^_^
Well there's that, but honestly... exploratory programming with a tool that can't provide basic functionality will limit how much you can explore. I think you mean 'language design exploration'? - if so I'll stop right there, since, well, frankly... it's not my wheelhouse. :)
> package integration first is putting the cart before the horse
I'm simply saying that features like db integration bring users, users bring manpower, manpower will provide package management in a way that ensures it accounts for more use cases, but again this is moot if what you're interested in is only the language development arena. Though I'm not sure how you could prove out a language unless you can actually use it for real world work.
P.S. If you want users, then killer feature would = todo list mobile app with local db in 30 lines of code!
> How would this be different than git submodules?
Most of the difference would be in the user interface. Git submodules might actually be a great idea for how to implement it, to encourage hacking on and submitting changes to the libraries themselves.
Git submodules don't provide a very friendly user experience though. You have to know the repository url and manage them separately. It's not terrible, but it's extra work, and doesn't handle loading the library in your own, or dependency management. Ideally, pulling in a package would also result in pulling in all of its dependencies, without pulling in multiple copies of the same library the way npm used to.
There are a lot more features that could be offered by an actual package system.
I agree it's important, and we should probably develop it and make it easier because it's an important foundation. However, there aren't that many Racket developers, and its not really the best argument in favor of using a language that it just happens to be a better version of another language. That might be a competitive advantage against Racket, but what about compared to other interpreted languages? Why would someone want to use arc over Python or Ruby?
> When I found out about Arc's Racket interop a couple of years ago, I was really surprised that this was not documented anywhere, so I added a section in the Readme.
Yeah, the documentation could use some work. Definitely not our competitive advantage at the moment, though that could be changed if we build on our interactive help system.
Also, that feature is really only part of anarki. I don't think arc3.1 had that feature. I think at this point it seems like pg has pretty well abandoned arc though, so maintaining compatibility shouldn't be a primary concern.
That would be nice I suppose, but we can't actually modify the arclanguage forum, so it would be of limited benefit. I guess a lot of people come to arc because they want to run an HN clone though, so it might be worth pursuing.
> File upload
Yeah, I think enhancing some of the fundamental web-service functionality in arc would be good. Beyond file upload, better support for OAuth, ssl, etc. would be good too.
Good idea. Not sure how to make that better myself, but demystifying and enabling easy ecommerce would be cool.
I think that also has the same motivation for the previous category; we need better support for web application development, because that's what most people want to do.