rascal-textmate

Background

The aim of this project is to design and implement a scalable converter from Rascal grammars to TextMate grammars. TextMate grammars generated in this way are intended to be included in VS Code extensions to provide syntax highlighting (complementary to Rascal's existing support for semantic highlighting).

In general, there are two possible approaches:

• total conversion: produce equivalent TextMate rules for all Rascal non-terminals;
• partial conversion: produce equivalent TextMate rules for some Rascal non-terminals "of interest" (e.g., those with a @category tag).

Due to the significant differences in expressiveness of Rascal grammars and TextMate grammars, this project applies partial conversion. Alternatively, a previous project by @TarVK applies total conversion.

Usage

Installing rascal-textmate

Enter the following commands in a terminal:

git clone https://github.com/SWAT-engineering/rascal-textmate.git
cd rascal-textmate/rascal-textmate-core
mvn install -Drascal.compile.skip -Drascal.tutor.skip -DskipTests
cd ../..
rm -rf rascal-textmate

Running rascal-textmate in an existing Rascal project

1. Add the following dependency in pom.xml of the project:

   <dependency>
     <groupId>org.rascalmpl</groupId>
     <artifactId>rascal-textmate-core</artifactId>
     <version>0.1.0-SNAPSHOT</version>
   </dependency>

2. Add |lib://rascal-textmate-core| to Require-Libraries in META-INF/RASCAL.MF of the project.

3. Open a REPL in a grammar module of the project, import module lang::textmate::main::Main in the REPL, and run function main on the start symbol of the grammar. For instance:

   main(#Foo, "source.foo", |home:///Desktop/foo.json|)

   The generated TextMate grammar (as a JSON file) can now be integrated in a VS Code extension as explained here.

Contributing

Documentation

The walkthrough explains the main ideas behind the conversion algorithm.

Tests

To test tokenization (as part of the conversion tests), the vscode-tmgrammar-test tool is used. Install it locally in directory rascal-textmate-core as follows:

npm install vscode-tmgrammar-test