The Dassie Programming Language

Dassie is a new programming language that runs on the .NET Common Language Runtime (CLR). It aims to provide a concise and simple syntax and to combine the best parts of object-oriented and functional programming, allowing for faster and more efficient development of all kinds of applications.

Getting started

To get started, install a Dassie compiler like the reference implementation at loschsoftware/dc. Unfortunately, since it depends on the .NET System.Reflection.Emit namespace that is only fully supported by .NET Framework, it currently only runs on Windows and only produces Windows executables. .NET 9, which will be released next year, is set to include the required functionality, which would allow the compiler to also target Linux and macOS.

Assuming you have downloaded the Dassie compiler and registered it under the %Path% environment variable, the command dc should be available from the terminal. It is used to compile Dassie source files and manage Dassie projects using the configuration file dsconfig.xml that is at the root of every project.

To start programming in Dassie, create a file ending in .ds. Here is the famous "Hello World" program written in Dassie:

println "Hello World!"

This prints to the console using a built-in function called println. Since Dassie uses .NET, you can also use its Console module like this, which should look familiar to .NET developers:

import System
Console.WriteLine "Hello World!"

Assuming the above code is located in a file called hello.ds, it can be compiled using the command dc hello.ds, yielding an executable called hello.exe. Alternatively, the command dc build can be used to compile all Dassie source files in the current directory and all subdirectories.

Design principles

• All code must be contained in a type. Like C#, Dassie allows for one file per project to have top-level code that is part of an auto-generated type and is declared as the entry point of the application implicitly.
• Everything from variable assignment to conditionals and loops is an expression. A loop returns an array of the return values of each iteration.
• Dassie uses operators for control flow. For example, the operator ? is used for conditionals instead of the commonly used keyword if. Loops use the operator @. Both conditionals and loops are available in a negated form, the so called unless and until expressions, represented by the operators !? and !@. Conditional and loop expressions are usable in prefix and postfix form.

Further information

A detailed documentation of the language syntax is available in the wiki of this repository. Code examples can be found in the examples directory.