Nested Dictionary typechecking

Hi, i have the following json structure and want to get rid of the typechecking warning:

        var myDict = { 
            "version" => "1.1.1", 
            "generator" => "logger", 
            "data" => [ { 
                "uuid" => "49f54392-1f4a-11e9-ab14-d663bd873d93", 
                "last" => 1671960103000l, 
                "interval" => -1, 
                "protocol" => "omv", 
                "tuples" => [ [ 1671960103000l, 20095964 ] ]
            } ]
        };
        var vers = myDict.get("version");
        var draw = myDict.get(["data"][0]["tuples"[0][1]]);

WARNING: ... \WebRequestDelegate.mc:13,8: Cannot determine if container access is using container type.

This looks similar to CIQQA-1327 but i can't explore the correct typedef syntax.

flocsy🤠 over 2 years ago

instead of the unsearchable "CIQQA-1327" can you link the ticket (bugreport forum thread)?

sscale20 over 2 years ago in reply to flocsy🤠

Sorry,

Can't define 2 dimensional Array in strict mode

Marianne.ConnectIQ over 2 years ago

Hi Former Member,

The type checker does not actually infer container types.

var myDict = { ... }

This code results in creating a local variable assigned to a value of type Toybox.Lang.Dictionary<Any, Any>. There are a couple of ways to remove the warning. You can use a brute-force approach and type cast (which kind of defeats the purpose of the type checker). Or you can type the dictionary:

import Toybox.Lang;

function foo() as Void (
    var myDict =
        { ...} as Dictionary<String, String or Array<Dictionary<String, String or Number or Long or Array<Array<Number or Long>>>>>;
    ...
    return;
}

Then, you would want to use if-splitting since Toybox.Lang.Dictionary::get returns a poly type of null (if the key value does not exist) or the original container type:

        var d1 = myDict.get(\"data\");
        if ((d1 != null) && (d1 instanceof Array)) {
            var d2 = d1[0][\"tuples\"];
            if ((d2 != null) && (d2 instanceof Array)) {
                var draw = d2[0][1];
            }
        }

I hope this helps and let me know if that wasn't the solution you were looking for,

Marianne

sscale20 over 2 years ago in reply to Marianne.ConnectIQ

Thanks for the explanation, as a hobbyist i would prefer to ignore the warning in favour saving 6 * x lines of code.