Class MyMathFold<Info>

Example: First you want to create your own fold:

let marker = false;
class MyNumberFold<Info> extends DefaultNormalizedAstFold<void, Info> {
    override foldRNumber(node: RNumber<Info>) {
        super.foldRNumber(node);
        marker = true;
    }
}
Copy

This one does explicitly not use the return functionality (and hence acts more as a conventional visitor). Now let us suppose we have a normalized AST as an RNode in the variable ast and want to check if the AST contains a number:

const result = new MyNumberFold().fold(ast);
Copy

Please take a look at the corresponding tests or the wiki pages for more information on how to use this fold.