- Immutability is leveraged to make a lot of core operations concurrent
- Continuation-based threading model and Actor-based concurrency
- Fun little VM implemented behind the scenes
That being said, the documentation strongly contradicts the title!
> The goal has not at any point been to become an ultimate Lisp and take over the world
dleink 19 hours ago [-]
> The goal has not at any point been to become an ultimate Lisp and take over the world
obviously something a lisp that had designated itself ultimate and was keen to take over the world would say.
ValentinA23 20 hours ago [-]
I'm wondering if a language could optimize immutable data structures to use mutable, in place semantics instead of duplication or structural sharing when it is possible. When an immutable data structure only has one consumer (only has one descendant in the flow graph), then it can easily be turned into a mutable version. Generalizing, any linear subgraph in the program's flow graph could be made to use in place semantics on the same mutable variable.
The challenge I guess is figuring out how variables captures by lambdas should be dealt with.
It provides the opposite: a mutable CoW data structure that is extremely cheap to "fork" so that all subsequent updates occur only on the new "fork" and are invisible to the old "fork".
zelphirkalt 20 hours ago [-]
Isn't that the point of well designed persistent data structures?
>I'm wondering if a language could optimize immutable data structures to use mutable, in place semantics instead of duplication or structural sharing when it is possible.
Yes, many languages (and libs, e.g. for JS) do that.
zelphirkalt 20 hours ago [-]
Does it feature implementations of lots of purely functional data structures then? Or does it only apply to a few builtins?
And would other Schemes be free to copy those?
rurban 23 hours ago [-]
tests/theorem-rand.scm is beautiful!
e.g.
theorem vec-zip
∀ v ∊ (Vector-of Short)
(vector-zip + v v) = (vector-map (λ (x) (* x 2)) v)
For additional context (I think some was lost on a bug tracker migration), he's the author of https://gitlab.com/akihe/radamsa, a fuzzer implemented in owl, that was quite popular finding vulns in the chrome codebase some time ago...
I wonder why it's called 'Owl Lisp' instead of 'Owl Scheme'. Could make a funny parallel to Chicken Scheme.
KineticLensman 20 hours ago [-]
Perhaps it's some sort of Web Ontology Language (OWL) [0]. Or a reference to Winnie the Pooh, as in "Owl took Christopher Robin's notice from Rabbit and looked at it nervously. He could spell his own name WOL, and he could spell Tuesday so that you knew it wasn't Wednesday" [1]
I suppose because it is not a Scheme and is a Lisp. :)
Pet_Ant 21 hours ago [-]
It is a Scheme:
> Owl Lisp is a functional dialect of the Scheme programming language. It
is mainly based on the applicative subset of the R7RS standard.
binary132 18 hours ago [-]
If it implements a subset of a scheme standard then it is not an implementation of a scheme standard. Is that not obvious?
Pet_Ant 18 hours ago [-]
I can't tell if you are joking or not.
If a platypus lays eggs, but it meets other criteria of being a mammal, it's still called a mammal. Owl may not be a full conforming Scheme implementation, but it seems to be member of the Scheme sub-family.
I'd say if you are a Lisp-1 (ie one namespace for variables and functions) and generally use the function names used by the Scheme standard then you are a Scheme (or Scheme-like-Lisp if you are very taxonomically retentive). However, if you are a Lisp-2 and use the function names of Common Lisp you're a Lisp.
Maybe if one were doing a deep dive on the history of Lisp and are into S-expressions vs M-expressions then it might be too loose, but I believe what is above is what most people would agree with in this context.
xdavidliu 21 hours ago [-]
it's right in the title of this thread, which comes from the project information of the repo
[more features, works in browsers vis webassembly too]
ianbicking 2 days ago [-]
The repo doesn't say much... I thought maybe the docs would justify "world domination" in some fashion, but they are rather dry: https://haltp.org/posts/owl.html
Is there something that describes what is notable about this Lisp dialect?
vincent-manis 1 days ago [-]
I haven't looked at it, but it's purely functional (so no destructive operations such as set!). It can't be called Scheme, because it's a subset of RnRS Scheme; that's why Racket isn't called PLT-Scheme any more. I can imagine this as a teaching tool (though the FAQ says the error messages aren't good), or perhaps usable as an extension language.
I'm going to look at it as a scripting tool that compiles to C.
I used to work for a company whose internal communication often claimed “world domination” as its ultimate goal. I just looked at revenue estimates for its market sector, this company isn't in the top 5, and is far behind the leader. Let's just leave Owl's world domination goal as aspirational.
tonyg 22 hours ago [-]
It's the other way around for Racket, where R5RS and R6RS are subsets :-)
IIUC Racket's new name came about from, basically, brand confusion: to avoid being (mis)understood as "yet another implementation of Scheme" rather than as the thing-in-itself it had become.
djaouen 15 hours ago [-]
> $ echo '(λ (args) (print "Hello, world!"))' | ol -x c | gcc -x c -o hello - && ./hello
This is frightening, yet awesome.
medo-bear 15 hours ago [-]
Im curious, how many people comenting here program in lisp/scheme?
LanternLight83 12 hours ago [-]
I thought hackernews sounded like an akward poll platform, so (just for fun) anyone who would like to vote can contribute here:
"Scheme for world domination", yet it has no Windows builds ;-)
Also, from the examples it looks like it requires (or at least recommends) an APL keyboard, or around a dozen macros for characters like λ, ∀, ∊, etc.
Still, this has to be one of the most practically useful Scheme (or Lisp) implementations that I've seen in a while.... Although it probably needs some getting used to for a Schemer who is used to having set! and friends....
Rendered at 12:50:53 GMT+0000 (UTC) with Wasmer Edge.
Key points include:
- 100% immutable datastructures
- Immutability is leveraged to make a lot of core operations concurrent
- Continuation-based threading model and Actor-based concurrency
- Fun little VM implemented behind the scenes
That being said, the documentation strongly contradicts the title!
> The goal has not at any point been to become an ultimate Lisp and take over the world
obviously something a lisp that had designated itself ultimate and was keen to take over the world would say.
The challenge I guess is figuring out how variables captures by lambdas should be dealt with.
It's great, one of the many awesome features Clojure has.
It provides the opposite: a mutable CoW data structure that is extremely cheap to "fork" so that all subsequent updates occur only on the new "fork" and are invisible to the old "fork".
I didn't see links on that page, but IIRC, there's a particular paper they reference as the main idea.
Yes, many languages (and libs, e.g. for JS) do that.
And would other Schemes be free to copy those?
e.g.
I just found out there's a rust port: https://github.com/microsoft/rusty-radamsa
[0] https://en.wikipedia.org/wiki/Web_Ontology_Language#Acronym
[1] https://en.wikiquote.org/wiki/A._A._Milne
> Owl Lisp is a functional dialect of the Scheme programming language. It is mainly based on the applicative subset of the R7RS standard.
If a platypus lays eggs, but it meets other criteria of being a mammal, it's still called a mammal. Owl may not be a full conforming Scheme implementation, but it seems to be member of the Scheme sub-family.
I'd say if you are a Lisp-1 (ie one namespace for variables and functions) and generally use the function names used by the Scheme standard then you are a Scheme (or Scheme-like-Lisp if you are very taxonomically retentive). However, if you are a Lisp-2 and use the function names of Common Lisp you're a Lisp.
Maybe if one were doing a deep dive on the history of Lisp and are into S-expressions vs M-expressions then it might be too loose, but I believe what is above is what most people would agree with in this context.
https://github.com/yuriy-chumak/ol
[more features, works in browsers vis webassembly too]
Is there something that describes what is notable about this Lisp dialect?
I'm going to look at it as a scripting tool that compiles to C.
I used to work for a company whose internal communication often claimed “world domination” as its ultimate goal. I just looked at revenue estimates for its market sector, this company isn't in the top 5, and is far behind the leader. Let's just leave Owl's world domination goal as aspirational.
IIUC Racket's new name came about from, basically, brand confusion: to avoid being (mis)understood as "yet another implementation of Scheme" rather than as the thing-in-itself it had become.
This is frightening, yet awesome.
https://www.rkursem.com/poll/view.php?id=e954c5a89f228a3e1
Also, from the examples it looks like it requires (or at least recommends) an APL keyboard, or around a dozen macros for characters like λ, ∀, ∊, etc.
Still, this has to be one of the most practically useful Scheme (or Lisp) implementations that I've seen in a while.... Although it probably needs some getting used to for a Schemer who is used to having set! and friends....