antlr4_builder #

A Dart package that integrates ANTLR4 grammar processing into the build_runner ecosystem, allowing you to automatically generate Dart lexer and parser files from your ANTLR4 grammars.

Features #

• Automated Code Generation: Automatically generates Dart lexer, parser, listener, and base listener files from .g4 grammar files during the build process.
• build_runner Integration: Seamlessly integrates with Dart's build_runner for efficient and incremental builds.
• ANTLR JAR Management: Automatically downloads the necessary ANTLR4 JAR if not already present, simplifying setup.
• Temporary File Management: Utilizes ScratchSpace for robust and clean management of temporary files generated during the ANTLR processing.
• Configurable ANTLR Version: Allows specifying the ANTLR version to use for code generation.

Getting started #

Prerequisites #

• Java Development Kit (JDK) (required for the ANTLR tool)
• Dart SDK (version 3.0.0 or higher)
• build_runner in your project's dev_dependencies.

Installation #

Add antlr4 to your project's pubspec.yaml under dependencies:

dependencies:
  antlr4: ^4.13.0 # Required for generated ANTLR code

And add antlr4_builder and build_runner to your dev_dependencies:

dev_dependencies:
  antlr4_builder: ^0.1.0 # Replace with the actual latest version
  build_runner: ^2.0.0 # Replace with the actual latest version

Run dart pub get to fetch the new dependencies.

Configuration #

Create or update your build.yaml file in the root of your project to enable the antlr4_builder:

targets:
  $default:
    builders:
      antlr4_builder|antlrBuilder:
        enabled: true
        options:
          # Specify the ANTLR version to use
          version: "4.13.2" 
          # Other options
          # ...
          # generate_listener: true
          # generate_visitor: true
          # extra_args: ["-Werror"]

Configuration Options #

The following options can be configured in your build.yaml under the options key:

• version: (String, required) Specifies the version of the ANTLR tool to use.
• generate_listener: (boolean, optional) Controls whether to generate a parse tree listener. Defaults to true. Corresponds to the ANTLR -listener and -no-listener flags.
• generate_visitor: (boolean, optional) Controls whether to generate a parse tree visitor. Defaults to false. Corresponds to the ANTLR -visitor and -no-visitor flags.
• extra_args: (List

Usage #

For a complete example, refer to the example/ directory in this repository.

Running the Example #

To run the example project:

1. Navigate to the example directory:

   cd example
   

2. Fetch the example project's dependencies:

   dart pub get
   

3. Run build_runner to generate the ANTLR Dart files:

   dart run build_runner build
   

4. Run the example application:

   dart run bin/main.dart
   

   You should see "Parsing successful!" in the console output.