Delegating global functions to Java with Jython

Turned out this is rather easy to do. You can put static functions into the Dsl class and those can be directly invoked inside the script.

Note: this is not exactly the same what Groovy does, because there you bind the local scope to an object rather than a class, but with some thinking this can be still very useful.

App.java

public final class App {
  public static void main(String[] args) throws Exception {
    try (PythonInterpreter py = new PythonInterpreter()) {
      py.exec("from hu.company.jythontest.Dsl import *");
      try (FileInputStream script = new FileInputStream("./etc/test.py")) {
        py.execfile(script);
      }
      var blocks = py.get("blocks", List.class);
      System.out.println(blocks.toString());
    }
  }
}

Dsl.java

public final class Dsl {
  public static class Block {
    private final String id;
    public Block(String id) {
      this.id = id;
    }
    public String getId() {
      return id;
    }
    @Override
    public String toString() {
      return id;
    }
  }
}

test.py

blocks = [Block('%d' % i) for i in range(10)]

Output:

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]