Halunke is Open Source and on Github. Try out Halunke online!

Halunke is a dynamic, object-oriented language that has a simple grammar inspired by Smalltalk and Lisp. It is created to show that interesting characteristics traditionally described as “functional” make sense in an object-oriented language:

Separation of identity and data (but not data and behavior)

Immutability and persistent data structures

Isolation of Side-Effects

Pattern matching

It also has the following characteristics:

There is no null/nil value in the language

Playing close attention to error message design

Install & Usage

Halunke is written in Ruby, and can be installed with:

gem install halunke

You can start a REPL with halunke or run a file with halunke file.hal .

Alternatively (if you don’t have Ruby installed for example), you can run it with Docker:

docker run --rm -ti moonglum/halunke

How it works

In Halunke, everything is an object. And you can send messages to Objects.

(1 + 2)

1 and 2 are both objects. You can send a message to an object by using parentheses: You first provide the name of the receiver followed by a message. In this case you send the message + to 1 with the value [ 2 ]. It will return the object 3 .

You can also send a message without any value. An example for that would be to reverse a string:

("Halunke!" reverse)

This will return "!eknulaH" . If you want to provide more than one value, it works like this:

("Halunke!" replace "Ha" with "Spe")

This will return "Spelunke!" . The message we send here is replace with and the value is ["Ha" "Spe"] .

If you want to find out more about the types of objects in Halunke and the messages you can send to them, explore the navigation bar at the top. If you want to learn more about conditionals, check out the section about True & False. If you want to write your own functions, check out Function and if you want to define your own classes, check out Class.

If you want to store an object in a variable, you can do it like this:

('a = 12)

Now you can send messages to a like (a + 2) . Why is there a ' though? The ' signals an unassigned bareword. That means you can send it a = message with a value, and it will assign it. Be aware that you can’t reassign. So if you assign something to a once, it will stay like this forever (within that scope). Reassigning will result in an error. There will be reassignable references in the future, see the issue for details

The values are also immutable. If you send a message to an object, it will not change the object, but it will return an answer to you.