Unable to evaluate string with "-"

Usecase - I’m trying to do nested lookup in Map. Issue - If the “.” separated key I’m searching in the map has “-”, then evaluation fails

public void test() {
    Map attribute = new HashMap<String, Object>() {{
        put("merchant_attributes", new HashMap<String, Object>() {{
            put("c652a326-5243-12ab-a4cd-111111", new HashMap<String, Integer>() {{
                put("num_orders", 2);
            }});
        }});
    }};

    MVEL.eval("merchant_attributes.c652a326-5243-12ab-a4cd-111111.num_orders", attribute); 
}

Evaluating the above test throws an error saying [Error: could not access: c652a126; in class:

[MalcolmOdd]

@MalcolmOdd How to escape strings that are starting with a number?

@Test
    public void test() {
        Map attribute = new HashMap<String, Object>() {{
            put("merchant_attributes", new HashMap<String, Object>() {{
                put("c652a326-5243-12ab-a4cd-111111", new HashMap<String, Object>() {{
                    put("1652a326-5243-12ab-a4cd-111112", new HashMap<String, Integer>() {{
                        put("num_orders", 2);
                    }});
                }});
            }});
        }};
        MVEL.eval("merchant_attributes[\"c652a326-5243-12ab-a4cd-111111\"][\"1652a326-5243-12ab-a4cd-111112\"]", attribute);
    }

This evaluates to null, the expectation was to return a object having num_orders attribute within it.

I tried it and it evaluates to a singleton map with num_order=2 your test was ignoring the result but I changed the last line to:

      assertEquals(Collections.singletonMap("num_orders",  2), MVEL.eval("merchant_attributes[\"c652a326-5243-12ab-a4cd-111111\"][\"1652a326-5243-12ab-a4cd-111112\"]", attribute));

When using strings as keys using the square brackets operator, the leading numbers do not matter.

[MalcolmOdd]

The dot operator expects an identifier on the right, and identifiers cannot have dashes (as it is parsed as the minus operator) or start with a number. You can use the square brackets to access it as follows:

      MVEL.eval("merchant_attributes[\"c652a326-5243-12ab-a4cd-111111\"].num_orders", attribute); 

The underscore “_” is valid to use in an identifier