Kolasu

Kolasu supplies the infrastructure to build a custom, possibly mutable, Abstract Syntax Tree (AST) using Kotlin. In particular, it can be integrated easily with ANTLR, but it can also be used on its own. Kolasu strives to be usable and idiomatic also in Java projects.

It stands for Kotlin Language Support.

Kolasu is part of the StarLasu set of libraries. The other libraries provide similar support in other languages such as Typescript and Python.

What can Kolasu be used for?

Kolasu has been used to implement:

• Parsers
• Editors
• Transpilers
• Code analysis tools

Features

Extend your AST classes from Node to get these features:

• Navigation: utility methods to traverse, search, and modify the AST
• Printing: print the AST as XML, as JSON, as a parse tree
• EMF interoperability: ASTs and their metamodel can be exported to EMF

Classes can have a name, and classes can reference a name. Utilities for resolving these references are supplied.

Kolasu tries to be non-invasive and implements this functionality by introspecting the AST. All properties, and therefore the whole tree structure, will be detected automatically.

Origin

Kolasu was born as a small framework to support building languages using ANTLR and Kotlin. It evolved over the time as it was used at Strumenta as part of open-source and commercial projects for building transpilers, interpreters, compilers, and more.

Using Kolasu in your project

Releases are published on Maven Central:

dependencies {
    compile "com.strumenta.kolasu:kolasu-core:1.5.0-RC1"
}

How to format code

Run:

./gradlew ktlintFormat

Projects using Kolasu

Kolasu is used in several internal and commercial projects developed at Strumenta.

Publishing

To publish releases you need to set the environment variables GPR_USER and GPR_API_KEY.