5 ms·

Wren: A classy little scripting language

200 points by Lyngbakr 1y ago

gnabgib 1y ago
Popular in 2022 (301 points, 130 comments) https://news.ycombinator.com/item?id=32631553 https://news.ycombinator.com/item?id=32631553 2020 (122 points, 54 comments) https://news.ycombinator.com/item?id=23660464 https://news.ycombinator.com/item?id=23660464
apitman 1y ago
I was working on a custom runtime for minimal wasm apps recently. I didn't want to have to write all apps in C or Rust, so I went looking for tiny scripting languages. Lua is pretty small, but I wasn't able to get it to compile to wasm IIRC due to POSIX dependencies. This turned out to be quite easy with Wren[0]. [0]: https://github.com/wren-lang/wren/issues/1199 https://github.com/wren-lang/wren/issues/1199
- MattJ100 1y ago
  That's unusual that you struggled to build Lua. Lua is primarily C89, and used on non-POSIX microcontrollers for example. There are some optional bits of the standard library you would have to leave out - module loading uses dlopen(). This is done simply by defining the right feature macros for your target environment: https://www.lua.org/source/5.4/luaconf.h.html https://www.lua.org/source/5.4/luaconf.h.html You may also be interested in this project: https://github.com/fengari-lua/fengari https://github.com/fengari-lua/fengari
  - nsagent 1y ago
    I've used fengari and it's a great option for lua in the browser, but it is quite slow.
  - JonChesterfield 1y ago
    setjmp/longjmp are irritating to implement and used by the pcall machinery
- Imustaskforhelp 1y ago
  Wow, I really went into a rabbithole after opening up your hackernews profile seeing indiebits and remembering my time scouring your github awesome tunneling page and then I went to discourse forum and somehow found new resources about self hosting and saw yunohost and others as well all in matter of minutes. Thank you for your service in self-hosting. I had so much fun trying to break nats with awesome tunneling projects and I even created my own but it actually requires a custom patch of ssh with pinggy to work without nat (let me know if you are interested, as I had discovered this a year ago but I just am a little lazy haha) I have created only one issue on the awesome tunneling but let me tell you some of them don't work in nat's/broke https://freedomhascost.bearblog.dev/ https://freedomhascost.bearblog.dev/ Just created the bearblog post, not sure why the name but just wanted to say thank you and wanted to share any knowledge I have in the process as well to strengthen the hacking/tinkering community. Thanks once again Also its just a bit of a coincidence that we are talking on a wren page as I was literally reading about wren once again and playing with it just yesterday and joined their discord server yesterday or day before that to tinker with it. Wren is really elegant and I feel like I want to write more software which integrates it instead of lua as a thought experiment as well and wasm seems a cool idea too in that regards.
  - apitman 1y ago
    Thank you for the kind words!
sandbags 1y ago
I would love to replace JS as the scripting language in one of my native macOS apps and I wonder if Wren would be suitable. The two biggest questions I’d have are: 1) how easy it would be to bridge Obj-C objects to Wren-space and vice versa (a big win of using JavascriptCore) 2) how easy would it be to implement script debugging? This is not exactly a strength of Javascript core but it is at least possible by connecting the Safari web inspector. There’s lots I don’t like about JS and JSCore but i’ve yet to find a better alternative.
reactordev 1y ago
This looks super cool up until I got to the point where it says inherited classes don’t share the same metatable. Meaning if you want to provide the same method on your inherited classes, you have to write the same thing and do a super.method() which means a lot of work if you’re into OO design so I’m not sure if classes is the right construct here. Am I wrong or did I miss something from the documentation? Other than that it looks like fun to use as an embedded scripting engine.
- nick__m 1y ago
  you probably meant metaclass and according to the doc classes inheritance don't have surprising behaviors. And about the metaclass not being inherited here are the implication: ...In more prosaic terms, this means that static methods are not inherited.
- pansa2 1y ago
  I think I read that Wren's creator deliberately avoided "the metaclass hierarchy matches the class hierarchy" (as used in Smalltalk and taken to an extreme in Ruby [0]) because the authors of Smalltalk have come to regret that design? I'd be interested to hear more details about the issues with that approach. I've not had any problems with it, and occasionally found it useful. For example, in one situation I needed a hierarchy of static constructors that matched the hierarchy of instance constructors. [0] Ruby also has "the meta-metaclass hierarchy matches the metaclass hierarchy" and "the meta-meta-metaclass hierarchy..." ad infinitum. It's a beautiful design really - it means that in Ruby (unlike Smalltalk), it's always true that "the superclass of the metaclass is the metaclass of the superclass". Edit: Here's the quote I was remembering: > My hunch is that we don't want metaclass inheritance. From talking to a few old Smalltalkers, they generally consider it a mistake there. Also, Java, C++, C#, etc. have semantics more similar to not allowing metaclass inheritance (in other words, static methods aren't inherited), and it seems to work well there. https://groups.google.com/g/wren-lang/c/LkKg51fEUg4/m/0GOK0PCxQr0J https://groups.google.com/g/wren-lang/c/LkKg51fEUg4/m/0GOK0P...
  - reactordev 1y ago
    Static method inheritance is one thing. Member method inheritance (or lack there of) makes it long in the tooth to work with if you want to represent covariant classes that share methods.
plainOldText 1y ago
Reminder the creator of Wren wrote the awesome Crafting Interpreters book [0]. [0] https://craftinginterpreters.com/ https://craftinginterpreters.com/
- l9o 1y ago
  This is awesome. Thank you for sharing. I have been working on a small interpreted language for shell scripts with lots of help from Claude Code. The main idea is to automatically generate the cli interface for the scripts based on function definitions. However, I'm far from a programming languages expert, so I've been a bit hesitant to share my work. Going to give this book a read this week to see how far I am. Thank you!
  - manveru 1y ago
    Take a look at how Nushell does this, it's quite neat: https://www.nushell.sh/book/custom_commands.html#documenting-your-command https://www.nushell.sh/book/custom_commands.html#documenting...
    - l9o 1y ago
      That's excellent. Somewhat similar to the syntax I went with, but most likely much better implemented. I'm going to give it a go. Thank you!
- mhaberl 1y ago
  and he wrote Game Programming Patterns [0] [0] https://gameprogrammingpatterns.com/ https://gameprogrammingpatterns.com/
- ronbenton 1y ago
  Knowing this is the author makes me 1000% more interested in Wren. What a great book!
- thw_9a83c 1y ago
  It is an excellent book and one of the canonical texts on the subject. My only suggestion for the "Lox" language would be to include an implementation of arrays, and preferably also hash/dict arrays. Other than that, the book contains everything you need to know about implementing a programming language.
bragr 1y ago
This seems like a nice alternative to Lua. I've always liked embedding Lua in other software, but I confess I have never really liked Lua as a language.
- versteegen 1y ago
  I really like the sound of Wren, but you may also want to look into Squirrel, it's basically Lua re-imagined/reimplemented but without all the Lua quirks and with C-style syntax (but it still has optional lua-style prototypes, which means it ends up very similar to Javascript). Its embedding API is largely a copy of Lua's. There is also an active fork called Quirrel that makes the language more like Python. There are loads of scripting languages but very few of them have an embedding API as powerful as Lua or Squirrel's. (My benchmarks: what's the overhead of a userdata pointer? Is there a proper debug API? Can you suspend a co-routine from inside a called C function? Very few languages even have coroutines.) Last I looked at it years ago, Wren was one of the best. Of course, the most featureful embedding API of all belongs to LuaJIT.
  - teo_zero 1y ago
    > you may also want to look into Squirrel Is it still active? Last release was in 2022...
    - versteegen 1y ago
      It's not being actively developed but gets some occasional patches on Github. It's mature (e.g. was used for a number of Valve's games). If you want an actively improving language, look at Quirrel.
    - archargelod 1y ago
      Most recent commit on the github[0] was only 11 months ago. Also, it's not a javascript framework, a stable software doesn't have to update often. Look at Lua, most people still use Lua 5.1 and that was released in 2006. [0] https://github.com/albertodemichelis/squirrel https://github.com/albertodemichelis/squirrel
tromp 1y ago
Wren ties with Phix for most tasks done on Rosetta Code [1]. [1] https://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_popularity/Full_list https://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_...
- elcritch 1y ago
  Wow that’s an interesting list. Sorta of surprising with Raku beating out Perl. Nim is also in the top 10, nice!
davidw 1y ago
Looks very nice! Erlang's concurrency isn't 'cooperative' though - it has a scheduler, so even a runaway process won't bog down the whole system.
gabrielsroka 1y ago
2016
ksymph 1y ago
Wren is the primary scripting language for the Luxe game engine, currently in development: https://luxeengine.com/ https://luxeengine.com/
atan2 1y ago
The first time I saw Wren was as an option for programming inside TIC-80. It caught my attention. I recently saw it again being mentioned by Gustavo (from pikuma.com) in his compilers course. Neat language and the VM code in C is quite easy to understand.
mathieudombrock 1y ago
Wren is super neat. I've written a few small games for TIC-80 using it. It's a really fun language to write.
pcfwik 1y ago
I once considered Wren for a situation where I (to a first approximation) wanted to allow users to write 'plugins' that link against my internal C application symbols but using a language focusing more on ease of use (rather than C). Unfortunately, neither Wren nor any of the other major 'embeddable scripting languages' (e.g., Lua) were really a good fit for this, because they commit fully to the 'all-numbers-are-floats' thing and generally don't seem to even try to provide a general equivalent to the C++ `extern "C" { ... }` thing. Of course, I know this isn't really the target use case of Wren/Lua/etc., but if anyone knows of a good embeddable scripting language for this I'd love to hear about it. Eventually I went with CPython (which provides ctypes to solve my problem) but it's a huge pain to embed properly.
- pansa2 1y ago
  > a general equivalent to the C++ `extern "C" { ... }` thing That sounds a lot like what LuaJIT’s FFI provides: https://luajit.org/ext_ffi.html https://luajit.org/ext_ffi.html
  - pcfwik 1y ago
    Oh awesome, thanks for the pointer!
- user____name 1y ago
  Lua's latest versions have integer support. Luau is a typed variant of Lua used by Roblox.
- 0x0203 1y ago
  I find myself referencing this list of embeddable scripting languages pretty frequently: https://github.com/dbohdan/embedded-scripting-languages https://github.com/dbohdan/embedded-scripting-languages Ones that might be of interest to you are Umka, tcl, and berry. There's also a lot of others listed that range from someone's experimental side project to professional grade and well supported languages. Kinda fun to see different people's approaches to things, and no matter what your preferred programming style, there's probably a few in there that will mesh pretty well.
- 1y ago
jossephus01 1y ago
wren has that minimalism from lua and syntax familarity from js that i always want to have in a scripting language. I was playing with it to build a raylib binding for it using zig a while ago and the language experience was too nice. You can checkout some examples of what you can achieve with raylib + wren here. https://github.com/jossephus/talon https://github.com/jossephus/talon
NetMageSCW 1y ago
Is Wren still under development? The last release appears to be 4.5 years old.
aj_hackman 1y ago
Interesting that this is back on the front page, as I've recently released a small-yet-growing standard library for Wren (which comes with its own modular plugin interface amongst other things): https://github.com/adamschackart/wrench https://github.com/adamschackart/wrench

200 points by Lyngbakr 1y ago

Popular in 2022 (301 points, 130 comments) https://news.ycombinator.com/item?id=32631553 https://news.ycombinator.com/item?id=32631553 2020 (122 points, 54 comments) https://news.ycombinator.com/item?id=23660464 https://news.ycombinator.com/item?id=23660464

apitman 1y ago

I was working on a custom runtime for minimal wasm apps recently. I didn't want to have to write all apps in C or Rust, so I went looking for tiny scripting languages. Lua is pretty small, but I wasn't able to get it to compile to wasm IIRC due to POSIX dependencies. This turned out to be quite easy with Wren[0]. [0]: https://github.com/wren-lang/wren/issues/1199 https://github.com/wren-lang/wren/issues/1199

MattJ100 1y ago
That's unusual that you struggled to build Lua. Lua is primarily C89, and used on non-POSIX microcontrollers for example. There are some optional bits of the standard library you would have to leave out - module loading uses dlopen(). This is done simply by defining the right feature macros for your target environment: https://www.lua.org/source/5.4/luaconf.h.html https://www.lua.org/source/5.4/luaconf.h.html You may also be interested in this project: https://github.com/fengari-lua/fengari https://github.com/fengari-lua/fengari
- nsagent 1y ago
  I've used fengari and it's a great option for lua in the browser, but it is quite slow.
- JonChesterfield 1y ago
  setjmp/longjmp are irritating to implement and used by the pcall machinery
Imustaskforhelp 1y ago
Wow, I really went into a rabbithole after opening up your hackernews profile seeing indiebits and remembering my time scouring your github awesome tunneling page and then I went to discourse forum and somehow found new resources about self hosting and saw yunohost and others as well all in matter of minutes. Thank you for your service in self-hosting. I had so much fun trying to break nats with awesome tunneling projects and I even created my own but it actually requires a custom patch of ssh with pinggy to work without nat (let me know if you are interested, as I had discovered this a year ago but I just am a little lazy haha) I have created only one issue on the awesome tunneling but let me tell you some of them don't work in nat's/broke https://freedomhascost.bearblog.dev/ https://freedomhascost.bearblog.dev/ Just created the bearblog post, not sure why the name but just wanted to say thank you and wanted to share any knowledge I have in the process as well to strengthen the hacking/tinkering community. Thanks once again Also its just a bit of a coincidence that we are talking on a wren page as I was literally reading about wren once again and playing with it just yesterday and joined their discord server yesterday or day before that to tinker with it. Wren is really elegant and I feel like I want to write more software which integrates it instead of lua as a thought experiment as well and wasm seems a cool idea too in that regards.
- apitman 1y ago
  Thank you for the kind words!

sandbags 1y ago

I would love to replace JS as the scripting language in one of my native macOS apps and I wonder if Wren would be suitable. The two biggest questions I’d have are: 1) how easy it would be to bridge Obj-C objects to Wren-space and vice versa (a big win of using JavascriptCore) 2) how easy would it be to implement script debugging? This is not exactly a strength of Javascript core but it is at least possible by connecting the Safari web inspector. There’s lots I don’t like about JS and JSCore but i’ve yet to find a better alternative.

reactordev 1y ago

This looks super cool up until I got to the point where it says inherited classes don’t share the same metatable. Meaning if you want to provide the same method on your inherited classes, you have to write the same thing and do a super.method() which means a lot of work if you’re into OO design so I’m not sure if classes is the right construct here. Am I wrong or did I miss something from the documentation? Other than that it looks like fun to use as an embedded scripting engine.

nick__m 1y ago
you probably meant metaclass and according to the doc classes inheritance don't have surprising behaviors. And about the metaclass not being inherited here are the implication: ...In more prosaic terms, this means that static methods are not inherited.
pansa2 1y ago
I think I read that Wren's creator deliberately avoided "the metaclass hierarchy matches the class hierarchy" (as used in Smalltalk and taken to an extreme in Ruby [0]) because the authors of Smalltalk have come to regret that design? I'd be interested to hear more details about the issues with that approach. I've not had any problems with it, and occasionally found it useful. For example, in one situation I needed a hierarchy of static constructors that matched the hierarchy of instance constructors. [0] Ruby also has "the meta-metaclass hierarchy matches the metaclass hierarchy" and "the meta-meta-metaclass hierarchy..." ad infinitum. It's a beautiful design really - it means that in Ruby (unlike Smalltalk), it's always true that "the superclass of the metaclass is the metaclass of the superclass". Edit: Here's the quote I was remembering: > My hunch is that we don't want metaclass inheritance. From talking to a few old Smalltalkers, they generally consider it a mistake there. Also, Java, C++, C#, etc. have semantics more similar to not allowing metaclass inheritance (in other words, static methods aren't inherited), and it seems to work well there. https://groups.google.com/g/wren-lang/c/LkKg51fEUg4/m/0GOK0PCxQr0J https://groups.google.com/g/wren-lang/c/LkKg51fEUg4/m/0GOK0P...
- reactordev 1y ago
  Static method inheritance is one thing. Member method inheritance (or lack there of) makes it long in the tooth to work with if you want to represent covariant classes that share methods.

plainOldText 1y ago

Reminder the creator of Wren wrote the awesome Crafting Interpreters book [0]. [0] https://craftinginterpreters.com/ https://craftinginterpreters.com/

l9o 1y ago
This is awesome. Thank you for sharing. I have been working on a small interpreted language for shell scripts with lots of help from Claude Code. The main idea is to automatically generate the cli interface for the scripts based on function definitions. However, I'm far from a programming languages expert, so I've been a bit hesitant to share my work. Going to give this book a read this week to see how far I am. Thank you!
- manveru 1y ago
  Take a look at how Nushell does this, it's quite neat: https://www.nushell.sh/book/custom_commands.html#documenting-your-command https://www.nushell.sh/book/custom_commands.html#documenting...
  - l9o 1y ago
    That's excellent. Somewhat similar to the syntax I went with, but most likely much better implemented. I'm going to give it a go. Thank you!
mhaberl 1y ago
and he wrote Game Programming Patterns [0] [0] https://gameprogrammingpatterns.com/ https://gameprogrammingpatterns.com/
ronbenton 1y ago
Knowing this is the author makes me 1000% more interested in Wren. What a great book!
thw_9a83c 1y ago
It is an excellent book and one of the canonical texts on the subject. My only suggestion for the "Lox" language would be to include an implementation of arrays, and preferably also hash/dict arrays. Other than that, the book contains everything you need to know about implementing a programming language.

bragr 1y ago

This seems like a nice alternative to Lua. I've always liked embedding Lua in other software, but I confess I have never really liked Lua as a language.

versteegen 1y ago
I really like the sound of Wren, but you may also want to look into Squirrel, it's basically Lua re-imagined/reimplemented but without all the Lua quirks and with C-style syntax (but it still has optional lua-style prototypes, which means it ends up very similar to Javascript). Its embedding API is largely a copy of Lua's. There is also an active fork called Quirrel that makes the language more like Python. There are loads of scripting languages but very few of them have an embedding API as powerful as Lua or Squirrel's. (My benchmarks: what's the overhead of a userdata pointer? Is there a proper debug API? Can you suspend a co-routine from inside a called C function? Very few languages even have coroutines.) Last I looked at it years ago, Wren was one of the best. Of course, the most featureful embedding API of all belongs to LuaJIT.
- teo_zero 1y ago
  > you may also want to look into Squirrel Is it still active? Last release was in 2022...
  - versteegen 1y ago
    It's not being actively developed but gets some occasional patches on Github. It's mature (e.g. was used for a number of Valve's games). If you want an actively improving language, look at Quirrel.
  - archargelod 1y ago
    Most recent commit on the github[0] was only 11 months ago. Also, it's not a javascript framework, a stable software doesn't have to update often. Look at Lua, most people still use Lua 5.1 and that was released in 2006. [0] https://github.com/albertodemichelis/squirrel https://github.com/albertodemichelis/squirrel

tromp 1y ago

Wren ties with Phix for most tasks done on Rosetta Code [1]. [1] https://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_popularity/Full_list https://rosettacode.org/wiki/Rosetta_Code/Rank_languages_by_...

elcritch 1y ago
Wow that’s an interesting list. Sorta of surprising with Raku beating out Perl. Nim is also in the top 10, nice!

davidw 1y ago

Looks very nice! Erlang's concurrency isn't 'cooperative' though - it has a scheduler, so even a runaway process won't bog down the whole system.

gabrielsroka 1y ago

2016

ksymph 1y ago

Wren is the primary scripting language for the Luxe game engine, currently in development: https://luxeengine.com/ https://luxeengine.com/

atan2 1y ago

The first time I saw Wren was as an option for programming inside TIC-80. It caught my attention. I recently saw it again being mentioned by Gustavo (from pikuma.com) in his compilers course. Neat language and the VM code in C is quite easy to understand.

mathieudombrock 1y ago

Wren is super neat. I've written a few small games for TIC-80 using it. It's a really fun language to write.

pcfwik 1y ago

I once considered Wren for a situation where I (to a first approximation) wanted to allow users to write 'plugins' that link against my internal C application symbols but using a language focusing more on ease of use (rather than C). Unfortunately, neither Wren nor any of the other major 'embeddable scripting languages' (e.g., Lua) were really a good fit for this, because they commit fully to the 'all-numbers-are-floats' thing and generally don't seem to even try to provide a general equivalent to the C++ `extern "C" { ... }` thing. Of course, I know this isn't really the target use case of Wren/Lua/etc., but if anyone knows of a good embeddable scripting language for this I'd love to hear about it. Eventually I went with CPython (which provides ctypes to solve my problem) but it's a huge pain to embed properly.

pansa2 1y ago
> a general equivalent to the C++ `extern "C" { ... }` thing That sounds a lot like what LuaJIT’s FFI provides: https://luajit.org/ext_ffi.html https://luajit.org/ext_ffi.html
- pcfwik 1y ago
  Oh awesome, thanks for the pointer!
user____name 1y ago
Lua's latest versions have integer support. Luau is a typed variant of Lua used by Roblox.
0x0203 1y ago
I find myself referencing this list of embeddable scripting languages pretty frequently: https://github.com/dbohdan/embedded-scripting-languages https://github.com/dbohdan/embedded-scripting-languages Ones that might be of interest to you are Umka, tcl, and berry. There's also a lot of others listed that range from someone's experimental side project to professional grade and well supported languages. Kinda fun to see different people's approaches to things, and no matter what your preferred programming style, there's probably a few in there that will mesh pretty well.
1y ago

jossephus01 1y ago

wren has that minimalism from lua and syntax familarity from js that i always want to have in a scripting language. I was playing with it to build a raylib binding for it using zig a while ago and the language experience was too nice. You can checkout some examples of what you can achieve with raylib + wren here. https://github.com/jossephus/talon https://github.com/jossephus/talon

NetMageSCW 1y ago

Is Wren still under development? The last release appears to be 4.5 years old.

aj_hackman 1y ago

Interesting that this is back on the front page, as I've recently released a small-yet-growing standard library for Wren (which comes with its own modular plugin interface amongst other things): https://github.com/adamschackart/wrench https://github.com/adamschackart/wrench