pyret-lang

Never heard about it before, it looks well done. Very interesting language. First a great point about the homepage: it goes directly to business, no marketing buzzwords, no stupid mascot, one glance at that page and any developer gets a very good idea of what that language does and doesn't. Second yes, they are very interesting choices and functions. However: https://github.com/brownplt/pyret-lang It's implemented in Javascript? This is a kind of no started for the kind of app I do, personally. But as a stand alone language which interpreter would be written in C/C++ and could be dropped into an existing native app, it would be interesting.

Actually it does, you can run it from Node.js https://github.com/brownplt/pyret-lang and use it as a scripting language.

Yes, you can run it from Node.js https://github.com/brownplt/pyret-lang and use it as a scripting language.

It's worth mentioning that Pyret followed this path. It was originally a Racket #lang. Once we got the design off the ground and decided to primarily target the browser, we wrote a new implementation in JavaScript and Pyret. The tools in Racket (including ragg [http://docs.racket-lang.org/ragg/]) were invaluable in getting started quickly. This archives the state of the system when we made the switch: https://github.com/brownplt/pyret-lang/releases/tag/pyret-20... Some things, like the grammar (https://github.com/brownplt/pyret-lang/blob/5f22ec7c8affde15...) have survived largely intact from that prototype for years.

This paper (http://cs.brown.edu/~sk/Publications/Papers/Published/fffkf-...) linked from "Why Pyret" (http://www.pyret.org/pyret-code/) is a long answer to "why teaching languages." It may also be useful to know that Pyret exists as part of a larger project and community. We're using Pyret to develop curricula for Bootstrap (http://www.bootstrapworld.org/), which integrates computing curricula into existing middle and high school classes, like math and physics. Part of the idea is to integrate computing into these settings to reach students who may not self-select for computing. A lot of Pyret's design, like a dead simple animation framework (https://www.pyret.org/docs/latest/reactors.html#%28part._to-...) and interfacing with real spreadsheets (https://github.com/brownplt/pyret-lang/wiki/TM028-Pyret-and-...), supports these low-friction

Pyret's runtime is entirely built on JavaScript (seriously: you can load https://code.pyret.org/editor, then turn off the network, and your IDE still works), and Pyret programs compile to JavaScript. At the command-line, it builds standalone JavaScript files that run under node. It's entirely possible to write pure JavaScript libraries that interface with the language (the compiler expects AMD style and requires that you write some small wrapping code). That's how the image library (https://www.pyret.org/docs/latest/image.html) works, for instance, and how we connect to Google Sheets (https://github.com/brownplt/pyret-lang/wiki/TM028-Pyret-and-...). Industry devs should be suspicious of Pyret's performance right now, though that will improve as time goes on. We've been spending most of our effort supporting our student and teacher user

As the sibling comment mentions, Pyret was originally written in Racket. It's now self-hosted, and I'm working on rewriting the typechecker so if you want I can answer questions about that. The current development is all done on https://github.com/brownplt/pyret-lang

Thanks for the kind comments. Sorry to hear about the crash, etc. We haven't gotten many reports about this; if you could file a bug report the next time (https://github.com/brownplt/pyret-lang/issues/new) we'd appreciate it! [But Firefox is _really problematic_ for various reasons. That may be half the issue.] Pyret's compiler is actually written in Pyret itself, so that it can run entirely offline. Once you have the initial page (which could be offline), you can literally turn off all networking and continue to work forever. Of course, saving files is then a problem—but I actually do this when I'm on planes (I copy my code to another file to backup). The _first_ load is indeed a bit of a problem. We're looking into various ways to reduce that. However, you should not have had delays on any subsequent runs. We have students in other univ

And on that note, be sure to take a look at Pyret, another programming language designed by this group, to address some of these student-oriented programming issues. https://github.com/brownplt/pyret-lang/ It is written all in JS (using Node) and can be completely run in a web browser apparently. I am not the first one here to mention it but it is very cool.

See previous HN discussion at https://news.ycombinator.com/item?id=6701688 and GitHub repository at https://github.com/brownplt/pyret-lang .

Maybe some lisp hackers gradually find out that a lot of parenthesis is not that fun for everyone. Not meant to enrage Lisp hackers, I actually find parenthesis bearable. There is also Pyret(http://www.pyret.org/) created by some people on the PLT team (you can confirm this by looking at the owner of their Github repo https://github.com/brownplt/pyret-lang). But more surprisingly it's implemented in JavaScript...

You can actually use ";" as an alias for "end" in Pyret, so you could write: data BinTree: | leaf | node(value, left, right); We use "end" or ";" in order to have unambiguous delimiters for the ends of syntactic forms and avoid needing to depend on whitespace (we added some discussion on pyret.org about our philosophy on indentation and why we don't want to depend on whitespace). Making that leading pipe optional is a good idea. I made an issue for it, we'll think about if it'll break or confuse anything and add it if it doesn't: https://github.com/brownplt/pyret-lang/issues/106

Pyret looks like a there's a lot going on, based on the examples. It has implicit returns, special purpose syntax for data structures, iterators, assertions, refinements, etc. Having support for more stuff makes it less suitable as a teaching language, not more. Pyret looks like a has the good bits of Python plus a whole bunch of other cool stuff. But the language is pretty complex as a result. Cool? Yup! Good for teaching? Probably not. Take a look at the grammar and judge for yourself: https://github.com/brownplt/pyret-lang/blob/master/src/lang/...