Explanation of seemingly very odd symbol syntax crash.

Unfortunately, afaik you can't use bracket notation (`[]`) to access arbitrary members of modules in the way you're trying to do with the second example. Toyboy.Sensor is a module, which explains the crash.

If "symbol" referred to a method, you would have a way of calling it, but since it refers to an enum, I don't think you can "dereference" it in the way you're trying to.

I totally get why you'd expect to be able to, tho.

It works in the first case because Rez.Strings is a dictionary.

flowstate said:

If "symbol" referred to a method, you would have a way of calling it, but since it refers to an enum, I don't think you can "dereference" it in the way you're trying to.

Hmm.

I mean... the practical evidence is in your favour that I can't refer to a module's constant in that way, but... you can with basically everything else... I've expanded my test to include enum, property and...

    var raw, symbol, obj;

    System.println("");
    System.println("START TEST STRINGS");
    raw = Rez.Strings.AppName;
    obj = Rez.Strings;
    symbol = :AppName;
    if(obj has symbol) {
        System.println("has symbol "+symbol);
        System.println("get "+Rez.Strings[symbol]+" should equal "+raw);
    }


    System.println("");
    System.println("START TEST THIS METHOD");
    raw = self.onLayout;
    obj = self;
    symbol = :onLayout;
    if(obj has symbol) {
        System.println("has symbol "+symbol);
        System.println("get "+self[symbol]+" should equal "+raw);
    }

    System.println("");
    System.println("START TEST THIS PROPERTY");
    raw = self.aValue;
    obj = self;
    symbol = :aValue;
    if(obj has symbol) {
        System.println("has symbol "+symbol);
        System.println("get "+self[symbol]+" should equal "+raw);
    }

    System.println("");
    System.println("START TEST THIS ENUM");
    raw = self.AN_ENUM;
    obj = self;
    symbol = :AN_ENUM;
    if(obj has symbol) {
        System.println("has symbol "+symbol);
        System.println("get "+self[symbol]+" should equal "+raw);
    }


    System.println("");
    System.println("START TEST STATIC VAR");
    raw = TestHr_F3View.staticBob;
    obj = TestHr_F3View;
    symbol = :staticBob;
    if(obj has symbol) {
        System.println("has symbol "+symbol);
        System.println("get "+self[symbol]+" should equal "+raw);
    }

    System.println("");
    System.println("START TEST SENSOR");
    raw = Toybox.Sensor.SENSOR_HEARTRATE;
    obj = Toybox.Sensor;
    symbol = :SENSOR_HEARTRATE;
    if(obj has symbol) {
        System.println("has symbol "+symbol);
        System.println("get "+Toybox.Sensor[symbol]+" should equal "+raw);
    }

Gets...

START TEST STRINGS
has symbol symbol (25)
get 1550 should equal 1550

START TEST THIS METHOD
has symbol symbol (8389122)
get method should equal method

START TEST THIS PROPERTY
has symbol symbol (42)
get something should equal something

START TEST THIS ENUM
has symbol symbol (41)
get 0 should equal 0

START TEST STATIC VAR
has symbol symbol (56)
get bob should equal bob

START TEST SENSOR
has symbol symbol (8388954)

Error: Unhandled Exception
Exception: UnexpectedTypeException: Expected Object/Array/Dictionary/ByteArray, given Primitive Module
Stack: 

Ah!

I've noticed something - I had self[symbol] rather than obj[symbol] in the above for the static one.

When I used the obj (class definition) I got an error.

So it could be that there is simply no object to read in a module.

Not intuitive, but probably defensible.

Primitive modules are 'special'. This is just one of the things that you cannot do with them.