This repository contains the code for a tutorial on the Truffle language implementation framework that I've written for my blog. It focuses on implementing a language I call EasyScript, which is a very simplified subset of JavaScript.

The repository is divided into multiple parts, each corresponding to a part of the blog article. Each part focuses on explaining a small set of Truffle capabilities, and builds on top of the previous parts by adding more features to the EasyScript language implementation.

Each part is a separate Gradle submodule, and so gets built when you build the top-level project.

To build and execute this project, you need a GraalVM installation on your local machine. The free Community Edition works fine if you don't have the paid Enterprise Edition. You can download it from here: https://github.com/graalvm/graalvm-ce-builds/releases. This repository uses Java 11 features, so make sure to download a version for Java 11.

Once you've downloaded the correct archive for your operating system and extracted it somewhere on your machine, you need to set the JAVA_HOME environment variable to point to the directory containing the uncompressed contents:

$ export JAVA_HOME=/path/to/extracted/archive

You can verify the installation works by executing the java command using JAVA_HOME:

$ $JAVA_HOME/bin/java -version

openjdk version "11.0.8" 2020-07-14
OpenJDK Runtime Environment GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03)
OpenJDK 64-Bit Server VM GraalVM CE 20.2.0 (build 11.0.8+10-jvmci-20.2-b03, mixed mode, sharing)

Once you have GraalVM installed, you can build the project - it uses Gradle as its build system:

$ ./gradlew build

• Part 1 - Node, RootNode, CallTarget
• Part 2 - introduction to specializations
• Part 3 - specializations using Truffle DSL, @TypeSystem
• Part 4 - parsing, and the TruffleLanguage class
• Part 5 - global variables