antlr4ng

I'm actually working with the new package in a large project and fixed a number of issues found while migrating from antlr4ts.

Out of the need to have a well working ANTLR4 runtime, which includes at least TypeScript type definitions, this package was created.

Note: to work out of the box this runtime needs parser files generated with an updated ANTLR4 tool jar, which is not yet available here. Will be in one of the next releases. Meanwhile you can use ANTLR4 4.13.1 and manually update the generated files, if you are in real need.