An package to use as a starting point for trying out Dart macros.

SDK setup

First, you need to ensure your SDK is sufficiently recent such that it supports macros. If it isn't new enough, you will get a version solve error when running dart pub get.

You can use either a very recently released dev SDK or a local build of the SDK.

Hacking on package:_macros

As long as you don't change any version numbers, you can hack on the _macros package in the SDK, do normal builds, and use that custom build SDK just as you normally would.

Hacking on package:macros

If you need to alter the published macros package, you will want to add a dependency override on it, to point at pkg/macros in your local SDK checkout.

The easiest way to do this is uncommenting the lines in the pubspec_overrides.yaml file, and updating the path to point to your SDK checkout

Running the example

You can run the example under bin normally on the Dart VM, by passing --enable-experiment=macros. So the full command would be:

dart --enable-experiment=macros bin/auto_to_string.dart

You can also run/debug from your IDE using the instructions below.

Setting up your IDE

VS Code

If you are using a version of the Dart extension for VS Code prior to v3.88.1 (or v3.39.20240513 if using pre-releases), you will need to set the "dart.experimentalMacroSupport": true, option in your VS Code settings (it's already set in .vscode/settings.json for this project).

To run/debug from VS Code, you will need to add "--enable-experiment=macros" to toolArgs in your .vscode/launch.json (it's already done for this project).

To run this example, open bin/auto_to_string.dart and press F5 (or click the Run/Debug CodeLens links).

Note that support here is still very early days, so please file issues as you find them.

Intellij

Use IntelliJ 2024.1 or newer with Dart plugin version 241.16006 or newer.

To run/debug from IntelliJ, you will need to add --enable-experiment=macros --release as "Additional run args" to the "Run/Debug Configuration" for your app.