Arc Forum | Yeah. B can probably work just fine with dynamically evaluated examples, but std...

Arc Forum

2 points by shader 3887 days ago | link | parent

Yeah. B can probably work just fine with dynamically evaluated examples, but stderr/stdout would require user interaction, which may not be acceptable. Maybe some way to indicate if an example should be evaluated or not?

What do you mean by 'run examples along with other tests'? Does that mean that you would include other tests in the help output? That the examples would be included when running the tests? Or something else?

1 point by akkartik 3887 days ago | link

The examples would be included when running the tests.

I'm less concerned with handling stdin, but the obvious example for do is:

  (do prn.1 prn.2 prn.3)

Surely we should be able to show that.

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1 point by shader 3887 days ago | link

That would work correctly with examples evaluated in the console, no?

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1 point by akkartik 3887 days ago | link

Yeah, I took your advice:

  (examples do
    (do (prn "line 1")
	(prn "line 2")
	(prn "line 3"))
    _)

Here's how it looks:

  arc> (help do)
  [mac] (do . args)
  Evaluates each expression in sequence and returns the result of the
  last expression.

  Examples:
    arc> (do (prn "line 1")
	     (prn "line 2")
	     (prn "line 3"))

Thanks! https://github.com/arclanguage/anarki/commit/14fff69c4

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2 points by fallintothis 3887 days ago | link

Actually, stdout should be easy to test with tostring, no?

In fact, if you're just testing REPL interactions...

  (mac repl-output (expr)
    `(tostring
       (write (eval ',expr))
       (prn)))

  arc> (repl-output (prn 'hi))
  "hi\nhi\n"
  arc> (repl-output (prn "hi"))
  "hi\n\"hi\"\n"
  arc> (repl-output 'hi)
  "hi\n"
  arc> (repl-output (do prn.1 prn.2 prn.3))
  "1\n2\n3\n3\n"

(Any gotchas with the above?)

It makes sense to specify the example expr / expected pairs as sexps & strings: run repl-output on exprs, compare those strings to the expected strings.

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2 points by akkartik 3887 days ago | link

Thanks for thinking through that! Yes, I'd had a similar though not as fully-formed idea, but was stuck on distinguishing stdout from return value in the examples. But yeah, that's overthinking it -- we have to mentally parse the two at the repl anyway.

Only other quibble: a string isn't very nice to read next to code, even if it looks nice at the repl. Hmm..

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2 points by shader 3887 days ago | link

Do you get notifications for arc forum posts/comments? Or do you just check really often?

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1 point by akkartik 3887 days ago | link

I'm just obsessive for short periods :)

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2 points by shader 3887 days ago | link

Ah. About the same as me then.

Maybe we should make an auto scraper/notifier? Though iirc, the arc server doesn't really appreciate frequent queries. On closer look, it should be fine; the default throttle window should be 10s. It could query once a minute, and update an rss feed for arc forum posts and comments. Or provide webhook + email support.

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1 point by akkartik 3887 days ago | link

I actually built one back in the day: http://akkartik.name/post/2011-05-13-05-47-29-soc. Trouble was, it kept getting banned/blocked even when I scaled back to crawl HN every five minutes. Eventually I was crawling so infrequently that I was missing stories that dropped off /newest in the meantime, so I stopped crawling.

I actually had an arc version for a brief period[1], but it didn't seem like there was as much need for it here. But perhaps the email notifications would be useful. I'll see if I can bring it back.

[1] I was certain I'd showed it here, but no I only showed it over email to a couple of folks. I really should bring it back just so y'all can look at it. Or at least locate the (rails) sources.

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