From the abstract: "A word of warning: The resulting approach is radically different from most teaching approaches used in universities and schools. In particular, it avoids teaching purely through examples and expecting students to develop the skills to arrive at the solutions on their own. Instead, it eaches explicit methodology that enables students to solve problems of surprising complexity on their own, whether they are 11 or 55, whether in a classroom, a training facility, or your home. Extensive documentation, material, and software to support this methodology is available for free."
One minor bit of criticism - would be it be so hard/expensive to hire a designer to do some minor touching up of the DrRacket GUI? It looks like a toy, and the icons didn't even look good in 1998.
I'll balance this criticism with the remark that any language/platform that manages to a) add, ex-post, a type system, b) fix the Gordian knot of modules and macros, and c) has the audacity (combined, curiously, with humility) to just swap out the entire backend to eek out more performance, deserves my respect. In addition both Flatt and Tobin-Hochstadt give excellent presentations where it's impossible not to notice their passion for Racket. They're definitely among my nerd heroes right now.
1) Install pict3d through DrRacket's built-in package manager - sudden, silent crash. Luckily I ran it from a terminal, which indicates an out of memory error.
2) Raise DrRacket's memory limit to "unlimited" and retry. Same result.
3) Google how to install packages from the command line. Wait for package to build. Build hangs during documentation. Eventually give up and ctrl-c. Hopefully it still works without docs? Racket packages aren't transactional, so every failed build leaves Racket thinking a package is installed, but it's actually broken.
4) Run DrRacket. Load pict3d and type oneliner. Incautiously press an F-key I assume will run the program. DrRacket crashes.
5) Run DrRacket. Load pict3d and type oneliner. Carefully run the program. Scene is incredibly slow but works! Then DrRacket hard crashes and locks my entire desktop so I have to go to a TTY to recover. My graphics are corrupted in a minor way. I haven't rebooted since then, and they're still corrupted.
I really, really like the look of Racket and want to use it in anger for a project, and I have a specific one in mind that would benefit from 3D, but this user experience is singularly bad. It's probably pict3d's fault, but there's no indication of this module being of "pre-alpha" stability. Or maybe it's an interaction with Racket-on-chez and C library interfacing. Let's hope it gets better.
Racket-on-Chez is what's pre-alpha. I don't think there's been requests for anyone to test it unless they were going to dig into the guts and try to fix things.
> since 3d is an application that needs speed
if the slowest part of your 3D is how quickly you can make calls into OpenGL, you're in a pretty good place.
Racket on Chez runs my code so I switched over but for most people it might be better to wait.
AFAIU typed Racket currently adversely affects performance on Racket CS (in certain cases) and pict3d looks like it's a non-base package written in typed Racket so it's likely not the best candidate for running on Racket CS right now.
(Personally I use xrepl instead, mostly because I don't like DrRacket's text editing. https://docs.racket-lang.org/xrepl/index.html)
Why would you need to maintain the old UI? Backwards compatibility isn't an issue, since no one is screenscraping and doing image recognition to interact with the UI.
Besides, what we're discussing are relatively minor changes to update appearance, such as different font, color scheme, graphics assets, etc. No significant changes wrt UX--with how the user interacts with the program.
I agree that shouldn't be an issue though. Those who don't want any change (e.g. lecturers) can stick with an old version.
Unfortunately they are not doing it for performance reasons. They are doing it solely to make the code base cleaner and easier to maintain.
Based on their most recent blog on the subject (https://blog.racket-lang.org/2019/01/racket-on-chez-status.h...), the new backend is almost uniformly slower to load, takes up twice as much memory, takes more than twice as long to build, takes twice as long to compile Racket code, and the compiled code generally runs slower than it used to. (They expect that this last one will improve, but they have never indicated that they expect it to actually match or exceed the speed of code compiled with the old backend.)
Also, the new back-end, by design, permanently removes support for the Racket C API.
This trade-off is hard for me to understand. I don’t maintain Racket, so I don’t have any idea how much effort this will ultimately save those who do. But I do know that I the main thing holding me back from investing more development time in Racket is its poor performance compared to languages like PHP, Python or Go; and I have never seen explained, and can’t even imagine, what new features the maintainers will now be able to implement that would actually make Racket development more productive or enjoyable.
According to them, fixing things takes much less time and is much easier to understand. For a system where lots of development is free, ease of understanding and fixing is extremely important.
> But I do know that I the main thing holding me back from investing more development time in Racket is its poor performance compared to languages like PHP, Python or Go
Racket is slower than Go because racket is dynamically typed, is a much higher-level language, and has to implement continuations. Racket is much faster than python or PHP.
My big issue with racket is dev tools. DrRacket isn't very good IMO. They need to make a server that implements the Language Server Protocol with some additional hooks for more dynamic lisp stuff. At that point, devs can choose to use all kinds of actually good editors (sublime, VS Code, Vim, Emacs, IntelliJ, etc) for coding. They can even add the LSP to DrRacket and continue to use it.
The new backed is overall faster according to that post.
I grant that there is some benefit in that the longer compile times result in an improvement in some benchmarks, but that doesn’t negate that the new back-end is still slower than the old one by every measure.
> Racket is much faster than python or PHP.
This is funny because although you will find benchmarks out there to support this point, in my experience of writing and using Racket programs it has never hold up. Most recent example: I participated in Advent of Code this year, and there was almost never a Racket solution posted that wasn't ten times slower (and in my opinion harder to read) than the simple & idiomatic Python solution.
I love the Racket language, and there are some DSLs like Pollen that do things I simply can’t imagine attempting anywhere else. But it’s for sure my last choice for speed, based on personal experience.
Can you point me to some examples of this? I haven't done AoC and so don't know where to find solutions posted to compare. It should be very rare for idiomatic python or php to be faster than idiomatic racket.
Since the rewrite (that was about 1.5 to 2x slower) less than a year ago 6 people had made commits.
What one could hope for would be some chez scheme interoperability for the really speed demanding parts.
A major mistake in any porting is to do big refactoring changes during the process.
As for why they are doing it, to remove the dependency in C, have a safer runtime that everyone in the Lisp/Scheme community would enjoy contributing to and have a bootstraped environment, removing the 2 language syndrome that plagues a few runtimes.
Call me a snob, but I think it's a bit eclipse-ish to have a splash screen. I'll stick with tmux + vim + parinfer + rainbow parens.
Favourite Scheme implementation. Offline searchable docs, libraries for everything. And developers are making it faster now with Chez?
There's a lot of useful discussion in here about parallelism which also applies to Ruby, Python, Lua etc.
Then I tried the stock Android Browser and it passed the browser check, but redirected to a login page.
Going back to Firefox and disabling uBlock Origin, I was able to access a description of the talk and the video itself. So I conclude that the video is available without login, but you have to use Firefox and allow yourself to be tracked.
Pretty grating "online experience" for something hosted on a mozilla.org subdomain.
Edit: the video file is here: https://airmo-7feeef12f503ef5d.s3.amazonaws.com/2014/02/06/4...
I think there must be a cultural disconnect between how people at Mozilla use firefox, and how users like us use Firefox.
Racket is an absolutely gorgeous language. It's the kind of language that might look complicated but the important thing is to start with the basics. Yes, there are complex features in the language and big words that might be scary : continuations, impersonators, collapsible contracts, macros. However most of the time you don't really need these features.
Even the basic features of the language are enough to make your software shine. After you have a basic grasp, start to tackle other features of the language refactoring your code as you go.
Another great feature is the community. racket-users mailing list (hosted in googlegroups) is a great place to start asking questions.
You'll have a lot of fun. Enjoy your time in Racket lang. #not-a-typo
You might, as a novice coming to Racket, find "Realm of Racket" to be more approachable as an intro: http://www.realmofracket.com/
Please don't. SICP is beautiful and all, but it's neither an intro nor practical/immediately useful. There's a lot of enlightenments to be had by reading it, but they have very little to do with Racket specifically. IMO, it's a bad book if your purpose is learning Racket.
> You might, as a novice coming to Racket, find "Realm of Racket" to be more approachable
Or, as an experienced programmer, be bored to tears by the slow pacing and didactical style. It's a great intro to programming and to Racket, but more focused on the former, which makes it ill suited for experienced devs who want to learn Racket.
I read SICP as an experienced programmer and I didn't find it impractical at all; in fact, it kickstarted my interest in other lisps.
I read Realm of Racket as an experienced programmer (after knowing Common Lisp and Clojure well) and it was entertaining and, yes, a gradual introduction to Racket.
I'm sorry if you disagree, but was answering the question that was given with a couple thoughts that might be beneficial. I'm glad you feel confident enough in your interpretation of what was being asked and the OP's personal background and motivation to flame someone else without, I don't know, answering the question.
EDIT: I see you did answer him below, but my general response is still valid.
EDIT 2: Your response makes more sense given context. Sorry I got internet angry a little too quickly.
What is obvious is that YMMV - I'm just saying what I'd do if I wanted to efficiently learn Racket today. That's it.
But, Racket reference docs are not a language definition like HS, RNRS or the Dylan book. The tutorials especially are quite friendly, but the reference is also full of examples, overviews, summaries and introductions, along with the links to the Guide - which can further help in comprehending the content (but only if needed, otherwise they stay out of the way). They're basically amazingly well done and I think more people should read them, if only to learn something about how to write docs and technical prose in general... :)
Also, I said it's a bad book for learning Racket In My Opinion. Of course it's all based on opinions and I just presented my own. No flame intended, at all.
EDIT: sure, no problem :)
Thank you for this. Time and again I have come across this book, but always assumed that it was something like The art of Programming series, so never even opened it.
Going through the online version now.
I think you can get an overview from the Wikipedia on S-expressions, then there's Dylan cheatsheet which translates Scheme syntax into equivalent forms in a language with more "normal" (infix) syntax, which also happens to be object oriented, so it should feel quite familiar(EDIT: thinking about it some more, maybe Dylan is still a bit too far from Algol-like syntax, but I can't find such right now). Then, there's Racket cheatsheet, and the Racket Tutorial. After writing some Hello Worlds and getting familiar with the syntax, start branching into interesting libraries (like plot, pict; see the list on  or search on ). See `raco pkg` docs for installing additional libs.
Advice about editor: find an S-exp support plugin for your editor and just go with that until you want some graphics support, in which case try DrRacket. Advice about weird things: try not to focus on weird things which are historical incidents - you can learn why CAR and CDR are called that way later, just remember that they are first/rest operations on lists.
After this I think Beautiful Racket along with the rest of the Racket docs should be enough to learn most of it. You can also skim How to Design Programs (linked at the end of tutorial) for intro to contracts.
Although I prefer to embrace the s-expressions :)
I agree about the extra dependency and indirection; although the syntaxes (syntaxen?) are equivalent, so examples can be translated automatically if copy/pasted.
> They're there if you want them, though.
Yep, although as I wrote on my blog:
"Whilst the parenthesis-heavy format of s-expressions is not necessary, it usually crops up in anything discussing Lisp and its derivatives, simply because it's much more popular than these alternatives. To me, that mostly indicates that concerns about "too many parentheses" are really a non-issue, despite being made by many who are new to the format."
It's discussed once every while on HN: https://hn.algolia.com/?q=htdp
The performances are meh (correct for a script language, but not much), the standard library is very large, it is portable, the integrated GUI and plotting facilities are absolutely priceless, and the ability to generate a fat ELF/.exe/.app for all of the three platforms is priceless.
Sure, distributing a 100MB executable is not something I would envision for a largely distributed software, but when hacking up (on Linux) a quick GUI tool for my lab colleague (on Windows), the advantages more than compensate for the drawbacks.
And I like LISP/Scheme languages, but that's subjective.
Yes, but the APIs design is very far from what you'd expect from a typical dynamic language. When you tell a typical Python/Ruby/Perl/PHP/Lua programmer that you can't just call `length` on anything collection-like, but need instead to call `string-length`, `vector-length`, `hash-size`, etc. - they remain unconconvinced, to say the least. The higher-order abstractions, like collections, sequences, streams are there, but rarely used (if at all) in the stdlib itself and you won't encounter them in tutorials. Then, some APIs are incomplete, like the date and time support, even with relevant SRFI.
The language is expressive enough, fortunately, for people to build their own stdlib replacements, like Alexis King's collections-lib (and related), gregor library for dates, or rackjure lib for thread-first/-last macros. But you need to know about them, otherwise you're going to invent lots and lots (because it's so easy) of your own conveniences and will do it poorly for the most part, while also losing time.
Well, it's still orders of magnitude better situation than with Pharo, which was also released in 7.0 version recently. In Racket, all of the stdlib is covered with extensive documentation comparable (sometimes favorably) with Python docs. Most additional packages are also documented the same way, it's great. As long as you can get past the base distribution lack of conveniences (or sometimes features), though, Racket is one of the most beautiful languages and language ecosystems I've encountered.
I did two little projects in Racket, recently: one was using Slideshow for making slides for a presentation, the other was using plot for making some graphs. In Slideshow, I ended up writing some 200 loc for it to display syntax-highlighted, colored code of non-Racket languages, which would be free in any JS-based presentation framework. After that it was a relatively smooth sailing, although the outline-generating API is definitely overcomplicated. In the other case, I had to parse a bit of text and then do a lot of computation on dates and times. Very frustrating experience initially, until I found gregor lib and megaparsack. The 5+ other solutions (for parsing) were too heavy-weight and inconvenient to use and I was just going to fall back on regexes (which are also not very convenient to use), but fortunately I found Alexi's megaparsack lib, which is almost as good as PyParsing.
Anyway - lots of rough edges in the stdlib, a lot of cruft - but at least well-documented - and some interesting libs you can use to bring it up to modern standards. And the module system makes using these packages painless - even if they rewire lots of stdlib - which is something Smalltalk/Pharo guys are yet to achieve.
Edit: according to wikipedia Arc, which HN is written in, is developed in Racket
I don't know if that situation with Arc has since changed though.
Moreso than being mainly created for teaching, Racket was created mainly as an environment for creating languages. Its forte is language development and implementation. This is useful in education, because it allowed them to easily create a number of 'teaching languages,' which are all essentially Racket with training wheels.
But that doesn't mean the base language + environment is only useful in education. I might even call it the most usable and productive LISP currently in wide use. (I greatly prefer it over Clojure, for instance.)
However, overall I like the language. So, overtime I think it’ll have its day in the sun.
You are misreading the release notes.
What was fixed is a Redex model (a tool used in semantics to model computer languages). A change to the modeling of `set!` (assignment) was made. It has no impact on Racket itself.
Unless you're the one who did the work, I'd rather trust the release notes than your unsourced assertion.
That said, just because a bug was fixed in an important function shouldn't be an indictment against the language. Racket is stable and productive, and formal modeling can reveal all kinds of corner cases which may not have been exposed in typical use, and may not have security implications. Maybe it was edge-case performance, maybe garbage collection, the release notes simply don't say.
I'd rather use a language whose authors improve their tools to discover and fix issues than one where this doesn't happen.