IssueTracker

Respectfully in regards to marking this duplicate. It is not quite a duplicate. That referenced ticket is part of SafeArgs, while this request is for typesafe navigation. It was marked as "infeasible", yet w'ere talking about two completely different bases.

In the last comment:

This requires support for doubles in NavInflater whose values are all backed by the TypedValue class, which unfortunately does not support Double values so we cannot go forward with this.

When in fact this is trivial to implement in compose typesafe navigation and seems to be a major omission:

object DoubleNavType : NavType<Double>(isNullableAllowed = false) {
    @Suppress("DEPRECATION")
    override fun get(bundle: Bundle, key: String): Double = bundle[key] as Double

    override fun parseValue(value: String): Double {
        // At runtime the d suffix is optional, contrary to the Safe Args plugin.
        // This is in order to be able to parse double numbers passed as deep link URL
        // parameters
        var localValue = value
        if (value.endsWith("d")) {
            localValue = localValue.substring(0, value.length - 1)
        }
        return localValue.toDouble()
    }

    override fun put(bundle: Bundle, key: String, value: Double) {
        bundle.putDouble(key, value)
    }
}

/**
 * Convience class to allow for double navigation types by turning them into strings and back.
 */
object NullableDoubleNavType : NavType<Double?>(isNullableAllowed = true) {
    @Suppress("DEPRECATION")
    override fun get(bundle: Bundle, key: String): Double? = bundle[key] as? Double?

    override fun parseValue(value: String): Double? {
        if (value == "null") return null
        return DoubleNavType.parseValue(value)
    }

    override fun put(bundle: Bundle, key: String, value: Double?) {
        if (value == null) {
            bundle.putSerializable(key, null)
        } else {
            DoubleNavType.put(bundle, key, value)
        }
    }
}

// in a route 
typeOf<Double>() to DoubleNavType,
typeOf<Double?>() to NullableDoubleNavType,

Similar to the work done in b/351994237 to expand the types supported by Navigation Compose Safe Args to support anything @Serializable can support, I think we can do something similar here to support doubles.