Method expression

src/stone/Parser.java:380–383

(Parser subexp, Operators operators)

        return this;
    }
    public Parser expression(Parser subexp, Operators operators) {
        elements.add(new Expr(null, subexp, operators));
        return this;
    }
    public Parser expression(Class<? extends ASTree> clazz, Parser subexp,
                             Operators operators) {
        elements.add(new Expr(clazz, subexp, operators));