Lux is a new programming language in the making. It's meant to be a functional, statically-typed Lisp that will run on several platforms, such as the Java Virtual Machine and JavaScript interpreters.
v0.3
The Java-bytecode compiler is almost complete.
Type-inference is halfway done and the compiler is not as fast as I would like.
However, programs can be written that can interop with the JVM and you can even publish Lux libraries to Clojars or Maven.
Download the 0.3 compiler from here: https://github.com/LuxLang/lux/releases/download/0.3.0/luxc.jar
Once you download the compiler, you'll want to create a directory named "source" in the same directory where the compiler is located.
You can run the compiler like this:
java -jar -Xss4m luxc.jar compile <program-module-name>
This will generate a directory named "target" and put all the .class files there. Then, you can run the program like this:
cd target/jvm/ && java -jar program.jar
To take a look at a sample Lux project, please take a look at this repository: https://github.com/LuxLang/luxdoc
The program in there was actually used to generate most of the documentation for the standard library in the wiki (located over here: https://github.com/LuxLang/lux/wiki/Standard-Library)
To make programming with Lux easier, you might want to checkout the new Leiningen plugin for Lux: https://github.com/LuxLang/lux-lein
Mozilla Public License v2.0
The language is mostly inspired by the following 3 languages:
- Haskell (functional programming)
- Clojure (syntax, overall look & feel)
- ML (module system)
The compiler is even implemented in Clojure.
They are implemented as plain-old data-structures whose expressions get eval'ed by the compiler and integrated into the type-checker. That means it's actually possible to generate types via functions. However, most of the types in the prelude are generated via several macros that provide a more pleasant syntax to types.
If you wonder what types look like without makeup, feel free to read the first few hundred lines of lux.lux.
The module system is heavily inspired by ML, and both signatures & structures are supported.
The main difference between Lux and ML is that ML separates signatures & structures from the rest of the language, whereas Lux implements them on-top of the base language.
How? By implementing signatures as record-types and structures as actual records.
Haskell's type-class system forces the user to only specify 1 instance for any given type-class and it's argument. This means that if there are more than 1 possible valid instances (as is the case for Monoid of Int), you have to resort to newtype hacks to be able to provide alternative implementations.
By using a system like ML's, that problem is averted. Also, by hosting the module system on top of records, which are regular values, you get the further benefit that structures can be parameterized at runtime just like any other data-structures. You can also write functions that take and return structures (as Functors do in ML) and you can generate structures on the fly.
While the means to do Java-interop will be provided (and there are already a few ways to do it that you can look-up inside lux.lux), Lux is commited to functional programming.
Functions are curried and partial application is as simple as just applying a function to less arguments than it needs (as in Haskell).
e.g.
(let [inc (i+ 1)]
(map inc (list 1 2 3 4 5)))
Many languages nowadays support compilation to multiple platforms (e.g. Haskell, Scala, Clojure). However, sharing code between platforms can be a pain in the neck due to the following reasons:
- differences in features between platforms
- the languages weren't originally designed with the goal of running both native/JVM and in JavaScript
Lux is being designed from the ground-up to target multiple platforms and achieve maximum reusability of code with minimum hassle.
The mechanism hasn't been added yet to the language (mainly because there's only 1 compiler at the moment), but it will come pretty soon in one of the upcoming releases.
Unlike in most other lisps, Lux macros are monadic. The (Lux a) type is the one responsibly for the magic by threading Compiler instances through macros. Macros must have the Macro type and then be declared as macros.
However, just using the defmacro macro will take care of it for you. Alternatively, you can use the defsyntax macro, which also offers monadic parsing of AST tokens for convenience.
Custom pattern-matching basically means that you can use macros to provide custom syntax & features on top of the pattern-matching macro (case).
For instance, the list and list& macros are used to build lists. But you can also use them to destructure them inside pattern-matching:
(case (: (List Int) (@list 1 2 3))
(#Cons x (#Cons y (#Cons z #Nil)))
(#Some ($ int:* x y z))
_
#None)
(case (: (List Int) (@list 1 2 3))
(\ (@list x y z))
(#Some ($ int:* x y z))
_
#None)
There is also the special \or macro, which introduces or patterns:
(deftype Weekday
(| #Monday
#Tuesday
#Wednesday
#Thursday
#Friday
#Saturday
#Sunday))
(def (weekend? day)
(-> Weekday Bool)
(case day
(\or #Saturday #Sunday)
true
_
false))
I'll be adding more useful pattern-matching macros in upcoming releases of the language.
If you want to see how they work, just check out their implementation inside lux.lux
Lux was born recently.
Come join the budding community by joining the discussion group at: https://groups.google.com/forum/#!forum/lux-programming-language
If you want to communicate with me directly, just email me at [email protected]
Check out the Emacs plugin for it: https://github.com/LuxLang/lux-mode
Just head to the wiki and check out the documentation for the currently available modules, and the tutorials.
Tags that are unprefixed will just assume the prefix of the current module you're in.
If you want to write variants/records with tags from lux.lux, you must do 1 of the following 2 alternatives:
- Fully prefix them: #lux;Cons
- Use the ; short-cut: #;Cons