ANTLR4 parse tree simplification

Question

Is there any means to get ANTLR4 to automatically remove redundant nodes in generated parse trees?

More specifically, I\'ve been experimenting with a grammar for GLS

Answer 1

Use the Visitor implementation to access each node in sequence. Build your own tree by adding nodes to parents as they are visited. Decide at the time the node is visited whether to add it to your new tree or not. For example:

public T visitExpression(@NotNull AcParser.ExpressionContext ctx) {
        // Expressionable parent = getParent(Expressionable.class, ctx);
        // Class expClass = AcExpression.class;
        AcExpression obj = null;
        String text = ctx.getText();

        //do something with text or children
        for (int i=0; i