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1 point by waterhouse 3348 days ago | link | parent

In fact arc3.1 even works on Racket, the new PLT Scheme. Only thing is that the command-line "racket" prints a newline after the "arc>" prompts, for some reason. But you can open as.scm with the editor DrRacket (as you could with DrScheme), set the language to be "Pretty Big", and hit Run; it will work.

1 point by bogomipz 3348 days ago | link

Wow, it seems to work fine with Racket 5.0, and I don't notice any issues with the prompt.

This should be mentioned on

Thanks for the hint, evanrmurphy!


1 point by waterhouse 3347 days ago | link

For some reason, now I don't notice any issues with the "arc>" prompt in "racket" either. And I don't think I'm doing anything differently than I was before. ...I am forced to conclude that, when entering things into the REPL, I held down the return key long enough that it accepted an extra (blank) line of input. This explains the behavior exactly. Strange that I should have done this several times in a row... and how embarrassing. Oh well. At least now I can give racket a clean bill of health.


1 point by prestonbriggs 3348 days ago | link

Not for me. Nor does it work with mzscheme. I get the complaint

ac.scm:1023:0: ffi-obj: couldn't get "setuid" from #f (The specified procedure could not be found.; errno=127)



1 point by waterhouse 3347 days ago | link

That is a known issue with Windows. (I'm guessing it's the reason arc3 is still the "official" version on the install page.) Simple workaround[1]: Find the line that says:

  (define setuid (get-ffi-obj 'setuid #f (_fun _int -> _int)))
and replace it with

  (define (setuid x) x)
I have done this on at least two Windows computers and Arc ran fine afterwards.



1 point by prestonbriggs 3347 days ago | link

Got it, thanks.


2 points by ylando 3346 days ago | link

Why arc do not have a normal web page; See:


2 points by akkartik 3346 days ago | link

Because it's unfinished (and may remain so). See and more recently No point sucking people in with a normal-looking webpage if the language isn't really ready for production use.


1 point by evanrmurphy 3344 days ago | link

Could you talk about your decision to use it for Readwarp then? If Arc's not really ready for production use, might it still be a good choice for a certain minority of developers?


2 points by akkartik 3344 days ago | link

Yeah, I'm not trying to say you shouldn't use it for production use :)

They're opposing perspectives. As a user of arc I'd throw it into production[1]. At the same time, from PG's perspective I'd want to be conservative about calling it production ready.

I suspect arc will never go out of 'alpha' no matter how mature it gets, just because PG and RTM will not enjoy having to provide support, or having to maintain compatibility.

[1] With some caveats: treat it as a white box, be prepared to hack on its innards, be prepared to dive into scheme and the FFI. And if you're saving state in flat files, be prepared for pain when going from 1 servers to 2.

Not all kinds of production are made the same.