Fix empty enum again

[kevinresol]

Closes #14

[kevinresol]

This is to guard infinite loop if something happens to be Unknown<0>.
For example, it happens when doing tink.Json.stringify(None), where the type is Option<Unknown>

[Gama11]

The '{ "EnumValue": {} }' case now works. Shouldn't '{ "EnumValue" }' work too though? For that I get:

Error: Error#422: Expected : at character 14 in { "EnumValue" ----> } <---- @ tink.json.BasicParser.die:237

[kevinresol]

'{ "EnumValue" }' is invalid json. This lib tries to represent haxe data with json syntax + macro magic. It doesn't modify the json synxtax itself. Without haxe macro, you can still parse it. Only it may not be very meaningful.

[Gama11]

Right you are, I was thinking about something like this:

class Main {
    public static function main() {
        var o:Struct = tink.Json.parse('{ "e": "EnumValue" }');
        trace(o);
    }
}

typedef Struct = {
    var e:TestEnum;
}

enum TestEnum {
    EnumValue;
}

[kevinresol]

I think for now the best thing you can do is this

enum TestEnum {
    @:json({type:'EnumValue'}) EnumValue;
}
trace(tink.Json.stringify({e:EnumValue})); // {"e":{"type":"EnumValue"}}

[kevinresol]

'{ "e": "EnumValue" }'

It is because the reader reads all enum values as object, so it always expects a {. (right after the colon in this case) It is a runtime task to determine a enum value to have arguments or not. So I don't think it is possible to support that.

[Gama11]

It is a runtime task to determine a enum value to have arguments or not

How so? You should know whether an enum constructor has arguments or not at compile-time, you know the enum's type after all.

Note that I have very little idea how tink_json works internally. :)

[kevinresol]

It is a runtime task to determine a enum value to have arguments or not

When the type is a Enum, the macro basically generate a piece of code that say: "hey we are expecting a enum, let's read it as an object and get the constructor name from within it". So, the parser will always expect a { at that point.
In other words, you can't tell the code to expect " instead of { just for a no-arg enum value. Because you can't know which enum constructor it is before you parse it.

[Gama11]

So it only checks the next character, meaning "expect either { or "EnumValue"" wouldn't work?

[kevinresol]

So it only checks the next character, meaning "expect either { or "EnumValue"" wouldn't work?

Well, that should work in theory. What I mentioned is the current status quo of the parser.