8 ms·
Racket 7.3
- nerdponx 7y agoAnd yet I'm still too stupid to understand the macro system. Oh well. I also didn't know there was a Chez version. Racket already has a native AOT compiler, right? What would the advantage be to run on Chez, faster or smaller compiled code?
- swdunlop 7y agoSee http://blog.racket-lang.org/2019/01/racket-on-chez-status.html http://blog.racket-lang.org/2019/01/racket-on-chez-status.ht... and scroll down to “Performance of Compiled Code.” That was back in January, so things may be even better now.
- jim-jim-jim 7y agoIs it the general Scheme syntax-rules macros that you're struggling with? Or something unique to Racket? (which I haven't used) If it's the former, I found this little article helpful when I was new to Scheme: http://www.willdonnelly.net/blog/scheme-syntax-rules/ http://www.willdonnelly.net/blog/scheme-syntax-rules/
- tgbugs 7y agoFor Racket specific macro tooling syntax-parse [0] in combination with syntax classes is usually the suggested starting point. Hygenic with pattern matching and a bunch of other features for parsing s-expression grammars. As mentioned down-thread Greg Hendershott's Fear of Macros [1] is a good starting point for a number of folks. The curriculum for Racket School 2018 [2] also has exercises that help introduce the syntax-parse tooling. 0. https://docs.racket-lang.org/syntax/Parsing_Syntax.html https://docs.racket-lang.org/syntax/Parsing_Syntax.html 1. https://www.greghendershott.com/fear-of-macros/ https://www.greghendershott.com/fear-of-macros/ 2. https://summer-school.racket-lang.org/2018/plan/ https://summer-school.racket-lang.org/2018/plan/
- xabush 7y agoThis is great tutorial. I used to be confused by the macros in scheme
- pjmlp 7y agoGetting rid of C dependency and bootstrap Racket in Scheme.
- darkpuma 7y agoTry out this guide perhaps: http://www.greghendershott.com/fear-of-macros/ http://www.greghendershott.com/fear-of-macros/
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- pyb 7y agoA few people exist who are genuinely able to use Racket macros, but they all have a PhD in CS. As opposed to the larger group who think they understand them. I was once in that group, but now I've just given up.
- NikkiA 7y agoRacket's macro transformers are about as easy as hygenic macros[0] get unfortunately, I can occasionally manage to make a er-macro-transformer based macro in chicken work how I want. defmacro was a lot easier, but I understand the aversion to it, even if it was rare that it was/is a problem. [0] syntax-rules based macros are cake, naturally, but they're also incredibly limited, although I have seen people implement massive complex OO systems using a sort of ad-hoc state machine built in pages upon pages of syntax-rules rules.
- Bogdanp 7y ago> And yet I'm still too stupid to understand the macro system. Oh well. This talk[0] by Robby Findler helped me a ton when I was first learning about macros in Racket. I've found that the best way to learn, though, is by doing: when you find a use case for a macro, figure out how to do that particular thing and, slowly but surely, things will start to click. [0]: https://www.youtube.com/watch?v=hFlIl0Zo234 https://www.youtube.com/watch?v=hFlIl0Zo234
- gus_massa 7y agoFor the macros, I prefer to recommend to start with very straightforward macros that use `define-syntax-rule`. For example #lang racket (define-syntax-rule (run3times code ...) (begin (begin code ...) (begin code ...) (begin code ...))) (define x 0) (run3times (set! x (add1 x)) (display x)) ; shows ==> 123 As other comment said, you have to find some good opportunity to use a simple macro. (In this case, it is better to use the build-in `for`. Actually, `for` is defined in a macro, it is not part of the internal "secret" low level language.) Once you are confident and you grok the difference between a macro and a function, you can try the other ways to define macros. These other ways are more flexible and can make weirder macros, and have better support when the macro is used wrongly. There are good links in the sibling comments.
- GeoffKnauth 7y agoAnother way to learn about all this stuff from the experts themselves is Racket School: https://school.racket-lang.org/ https://school.racket-lang.org/
- Labo333 7y agoI am really excited by Racket. Unlike most minimalist LISP languages with a community of individual hackers who each have their own macros and packages, this one is battery included while still being the most flexible with the #lang header. Seriously, it comes with awesome data structures (actuelly more than Python). The only thing that prevents me from using it as much as Python or C++ is the lack of tools for major editors. DrRacket is NOT ok, I would like a langserver and vscode extension so badly! When I have a bit of free time and have finished other projects with a higher priority, I'll definitely give it a try. (yes I'm aware there are some langservers but none of them is really production ready)
- Veen 7y agoEmacs has a decent Racket mode with most of the functionality of DrRacket.
- soegaard 7y agoThese days racket-mode for Emacs is more than decent! Could wish for similar modes for SublimeText and VisualCode though.
- cercatrova 7y agohttps://marketplace.visualstudio.com/items?itemName=evzen-wybitul.magic-racket https://marketplace.visualstudio.com/items?itemName=evzen-wy... For VSCode
- Labo333 7y agoThanks for the pointer, I'll try and see whether I can port racket-mode as a vscode extension.
- yomly 7y agoDo Naughty Dog still use Racket? Anyone from there able to give some insight into what tools/dev environment they use there?
- stesch 7y agoFont looks like shit in Firefox on macOS X.
- laszlokorte 7y agoMaybe link to the blog post [1] instead. [1]: https://blog.racket-lang.org/2019/05/racket-v7-3.html https://blog.racket-lang.org/2019/05/racket-v7-3.html
- Veen 7y agoFor reasons I find difficult to understand, the text is between <pre> tags and uses a monospace font (Inconsolata). It is curious that a project that cites Matthew Butterick as a contributor should make such poor decisions about typography, especially when the rest of the documentation is above average in that area.
- velcrovan 7y agoMatthew is a contributor, doesn't mean he is the Jony Ive of every single web page they publish.
- Veen 7y agoNo, but he is the “Jony Ive” of the website on which that announcement is published.
- dragonwriter 7y agoIt's wrapped in <pre> tags because it is preformatted text of the type that would be used in email, etc., announcements (probably becauae it's the exact text from those media, without transformation), so not using <pre> would lose significant formatting. Of course, the formatting is broken anyway, because two of the continuation lines of bullet-pointed lines are underindented by one space.
- stesch 7y agoMaking the font bold is what makes it look so bad in Firefox. In combination with the font.
- lenkite 7y agoI really wish there was a standard Scheme that compiled to native for all desktop and mobile OS'es and also supported multi-threading. Does anyone know about one ?
- rgrau 7y agoLambdaNative is a cross-platform development environment written in Scheme, supporting Android, iOS, BlackBerry 10, OS X, Linux, Windows, OpenBSD, NetBSD, FreeBSD and OpenWrt. http://www.lambdanative.org/ http://www.lambdanative.org/
- lenkite 7y agoLambdaNative is a wrapper and abstraction over Gambit Scheme. It does not support multi-core threading.
- rgrau 7y agoWell, that was my best shot :(. I'm sorry I don't have an answer then. You were asking for threads, and gambit has lightweight threads, so I assumed there was a way to use them via ln. Multi-core threading is a different story though.
- lenkite 7y agoYes, it's a bit of a pity that great functional languages like Scheme and even the veteran common LISP are loosing out to modern languages like Kotlin because of lack of support in these critical, functional areas. Especially when REPL based development is so amazingly productive.
- rgrau 7y agoIndeed I miss CL's "live coding" every day since.
- bananaoomarang 7y ago
- bjourne 7y agoIs typed racket still very slow? I'm interested in hearing how Racket's gradual typing works.
- Bogdanp 7y agoIt depends upon what you mean by slow. Typed Racket code compiles more slowly than normal Racket code, but should run about as fast or faster (for a small set of specifically-typed code[0]). [0]: https://docs.racket-lang.org/ts-guide/optimization.html https://docs.racket-lang.org/ts-guide/optimization.html
- chriswarbo 7y agoTyped racket isn't slow (as far as scripting languages go). Maybe you're thinking of Racket's "contract" system? AFAIK typed racket does type-checking during compilation (via raco); the resulting code is no slower than normal Racket, although I'm not sure if it's faster either. The contract system is different; it works on normal, untyped Racket code and performs checks at runtime; similar to using Python decorators to check the input and output of a function. This slows things down, so it's recommended to only check things at module boundaries. For example: #lang racket (require racket/contract) (require racket/match) (provide factorial) (define/contract (factorial n) (-> exact-nonnegative-integer? exact-nonnegative-integer?) (fact n)) (define (fact n) (match n [0 1] [_ (* n (fact (- n 1)))])) This module exposes the `factorial` function, which checks (at runtime) whether its argument and return value are non-negative integers (i.e. 0, 1, 2, ...). The actual calculation is done by the `fact` function, which is private and doesn't do any checks. If we don't separate the checks from the calculation, we would end up running the checks on every recursive call, which would slow things down a lot. As far as I'm aware, Racket's gradual typing is done by contracts at the interface between typed and untyped code. Hence it's not that typed racket is slow, it's that passing untyped values into typed functions can be slow, if we want accurate blame information for errors.
- bjourne 7y agoI'm referring to Takikawa et al (2016), who reported performance 50-100 times worse performance numbers by mixing typed and untyped Racket code together. Actually 100 times slower execution. They used type annotations on the module level. Would be interesting to know if Racket developers have proven them wrong and if so, how. http://www.ccis.northeastern.edu/home/types/publications/gradual-dead/pre-treatment.pdf http://www.ccis.northeastern.edu/home/types/publications/gra...
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