I'm trying to convert a `JsonObject` to `Map<String, Any>` , but am stumped on `JsonPrimitive`...

# serialization

[Richard Gomez]

I'm trying to convert a JsonObject to Map<String, Any> , but am stumped on JsonPrimitive.
It stores all values as String, so it doesn't seem possible to get a float/boolean/etc. unless you know its type ahead of time.

Is there a (simpler) way to accomplish this?

[Richard Gomez]

For example, Vert.x's JsonObject has a getValue method which returns the raw type (and stores the raw types in the underlying map).
https://github.com/eclipse-vertx/vert.x/blob/3682ec2b1283b1b30751bef2b816cf04c173fd21/src/main/java/io/vertx/core/json/JsonObject.java#L388-L391

[ephemient]

there's extensions to return different types, `.boolean`/`.double`/`.float`/`.int`/`.long` (and ._OrNull

[ephemient]

oh right, you do need to know what you're looking for ahead of time

[Richard Gomez]

Exactly. You could do a hacky workaround and chain all the orNull methods together, but that would be imprecise at best.

[ephemient]

in any case, JSON itself doesn't have distinct numeric types…

[ephemient]

e.g. 1.0 is equivalent to 1

[ephemient]

so it seems to me that this would be as accurate as anything could be, without knowing the schema beforehand

when {
    jsonPrimitive is JsonNull -> null
    jsonPrimitive.isString -> jsonPrimitive.content
    else -> jsonPrimitive.content.toBooleanStrictOrNull()
        ?: jsonPrimitive.content.toBigDecimal()
}

[Richard Gomez]

Thanks @ephemient. I've expanded based on your POC.

Relevant GitHub issue: https://github.com/Kotlin/kotlinx.serialization/issues/1298#issuecomment-934427378

[ephemient]

as I alluded to above, guessing int/double based on formatting is not appropriate for JSON, because JSON has no distinction between them and it is completely valid to use 1.0 to represent 1 (int) and vice versa

[Richard Gomez]

Yeah, that's by no means a perfect or extensive strategy. More of a "I have a specific use case where this reliably works" solution, lol.