Method eval

src/chap10/ArrayEvaluator.java:28–36

(Environment env, Object value)

    @Reviser public static class ArrayRefEx extends ArrayRef {
        public ArrayRefEx(List<ASTree> c) { super(c); }
        public Object eval(Environment env, Object value) {
            if (value instanceof Object[]) {
                Object index = ((ASTreeEx)index()).eval(env);
                if (index instanceof Integer)
                    return ((Object[])value)[(Integer)index];
            }

            throw new StoneException("bad array access", this);
        }
    }
    @Reviser public static class AssignEx extends BasicEvaluator.BinaryEx {
        public AssignEx(List<ASTree> c) { super(c); }