Can you tell me your OS? I've only been using OSX so it's possible it's chrome on Windows? Versions would be great too, if you can :)

And is that a js error or a server error? I'm hazarding a guess it's a js error given I'm not seeing any errors on the server.

note this is in the very experimental stages. I wouldn't try it on mobile or IE yet.

Posted it on HN too,

https://news.ycombinator.com/item?id=19902880

From what I gather using those along with Clojure 'Spec' allow you to create ad hoc, generalized interfaces as an abstraction layer accessing an infinitely large lazy tree of 'things' (provided these 'things' are data or can hold meta data).

Unfortunately I have yet to see anyone really use it in the way I imagine it can be. I'd like to see a web 'req' var with the ability to drill down through the server-code<->js-code barrier (via the session and connection protocol) all the way down into the dom and the js application state. That would be really, really cool.

Also, I've been building a general purpose app builder (for web apps). This app building process is currently working, but in the future I'll need build a more advanced inspector and a designer. Since my stack is Clojure from server to js I'm wondering if it makes sense to build the inspector on top of that trio of technologies then attach the designer to it.

Someday I'll get to do that! ... I just know it. :)

Edit: for those who wonder what this has to do with REBL... these are the core technologies that REBL is built upon.

I don't 'discord' so maybe someone else has insight?

I've used it in production at multi-national organizations.

In fact that's how I learned to code. 10 years ago I was a business analyst who couldn't get the dev group to work on my projects in a timely fashion. The ability to use arc was in reach for me, even though I had no programming experience at all.

I actually wrote and released 2 internal apps and 1 external app that had good use (a few hundred users using it daily/weekly to get their jobs done). This was in production for a few years until I left in 2012. I'm pretty sure they're not using these apps anymore.

> What sorts of systems would it excel in and what sorts would it be unsuitable for?

I think its primary strength is the short learning curve. I also I think it's unsuitable for anything which needs to use existing db connections. Even though I did hacks to make that work it's the primary reason my apps could not be adopted by the dev group.

> What could be done to alleviate for Arc’s lack of features?

  * better db integration

edit:

> In fact that's how I learned to code. 10 years ago...

lol, my first post on arc from 10 years ago:

http://arclanguage.org/item?id=8658

It's kind of ironic my first post was about a most recent topic[1]:

  "After playing for a bit I noticed my "set x" functions were 
  clobbering each other...so I started converting all my function to use 
  "let" statements."

 "why wouldn't the ARChitects of LISP or ARC make a set like 
  function that is global within a function ?

And how often is it intended behavior? How often does one want to have a macro parameter or apparently "local" variable overwrite an existing symbol globally and arbitrarily?

I can see it being useful in the case of "hot patching" code to just redefine a function, but that's still kind of crazy, since now the source code and running code are no longer the same. Might as well just edit the file and reload it, and have one source of truth.

We're referring to the original posts problem where using = inside a function can redefine global variables:

  arc> (= data* '(green red)) 

  arc> (def my-fn () (= data* nil))
  #<procedure: my-fn>
  arc> (my-fn)
  nil
  arc> data*
  nil

assume you place this in html.arc

  (= data* '(blue red))

  ; (add-color 'purple)
  (def add-color (color)
    (push color data*))
    

  (= data* '(green red))

  ; (add-apple 'golden)
  (def add-apple (color)
    (push color data*))

  (load "lib/apples.arc")
  (load "lib/html.arc")

  > (string (car data*) " has gone brown")

  "blue has gone brown"

This is where js would be handy - right? Personally I would just update the dom element and send a http post in the background.

I get that it's just a toy, but still it shows that languages* should have a good client side story too. Maybe some Lumen integration?

* that are for the web.

We started out by making an EventSource endpoint and using JS EventSource object to get updates. Seemed to work great.

Pushed it live.

To everyone on the site. Not just to the people on /l/place. Oops. Mistake #1.

Mistake #2: I was aware that Arc kills threads that take longer than 30 seconds, but I was unaware that EventSource automatically tries to reconnect. Welcome to the DoS party.

With no way to tell the clients to stop. Mistake #3.

It was only live for about 10 minutes, but it took around two hours before the last few clients finally refreshed their browser and stopped DoSing the endpoint. The server absorbed the extra traffic like a champ, but the server logs were ridiculous for about an hour. Lots of "client took too long" error messages spit out by Arc every second.

Sooo yeah, submitting changes via JS is easy. Getting updates is the hard part.

Could poll. But then that's still hammering the server. Moreso than it already is.

It's probably a feature that it's painful to use. Only the determined will use it for art.

> I was aware that Arc kills threads that take longer than 30 seconds...

> Sooo yeah, submitting changes via JS is easy. Getting updates is the hard part.

That's why I suggested a post request...

Just deliver the page and create an api end point, on the server, that gives you the last x changes from the change log.

With that ajax request, you could return these net updates for the client and use client side js to apply them to the dom. You could even create a trivial js debounce[1] algo to throttle requests if you wanted to go even further.

As it is, the more "pixels" you have, the slower the page loads. You could probably have just a single canvas and a single event handler.

The repo's open, and I could help get you set up with it if you wanted to work on some of this. https://github.com/laarc/laarc

It should be a matter of:

  git clone https://github.com/laarc/laarc
  cd laarc
  make
  rlwrap bin/arc
  ((load "news.arc"))

If it's to be done in JS, might as well implement a drawing tool in an actual canvas element.

I will say; I did a page reload and noticed the color pick was still in place and had to go hunt for the x. I expected it to reset, but I'm not sure if you see that as a bug or a feature :)

The trick to clear the x is to scroll up and click on the color palette.

> If you want to switch back to arc, you can use (%do ...)

Personally I would prefer '.arc' or '%arc':

  arc> (begin (require racket) (.arc (+ "foo" 42)))

  "foo42"

.arc / .racket (or .rkt) seems more intuitive than .arc / $