Hi! I have this function ``` private fun getFields(): List<KProperty<*>> { v...

# getting-started

[Tech]

Hi!

I have this function

private fun getFields(): List<KProperty<*>> {
        val kClass = this::class

        return cachedFields.getOrPut(kClass) {
            kClass.declaredMemberProperties
                .filterNot { it.javaField?.isSynthetic == true }
                .onEach { it.isAccessible = true }
                .map { it }
        }
    }

It works fine however, when it retrieves all declared properties it doesn't do them in the order they're declared, example

data class Example(val a: String, val b: String)

So b can be gotten before a, is there any way to do this that maintains order that they're declared without using annotations?

[Youssef Shoaib [MOD]]

You could cross reference the property names against the parameter names for the primary constructor and thus obtain the ordering, but that only works if it's a data class

[Tech]

Yeah that's fine, I only need constructor params

[Youssef Shoaib [MOD]]

This might help: https://github.com/arrow-kt/arrow/blob/main/arrow-libs/optics/arrow-optics-reflect/src/main/kotlin/arrow/optics/Reflection.kt

[Tech]

Interesting, tysm
I'll come back if I need further help 👍

[Tech]

aaandd it worked first try.
Updated code if anyone needs reference,

return cachedFields.getOrPut(kClass) {
            val p = kClass.primaryConstructor
                ?.parameters
                ?.withIndex()
                ?.map { (index, param) -> param to index }
                ?: error("Primary constructor not found for class ${kClass.simpleName}")

            kClass.declaredMemberProperties
                .filterNot { it.javaField?.isSynthetic == true }
                .onEach { it.isAccessible = true }
                .sortedBy { p.firstOrNull { (param, _) -> param.name == it.name }?.second }
                .map { it }
        }

[Tech]

Thank you so much!

[Youssef Shoaib [MOD]]

return cachedFields.getOrPut(kClass) {
            val p = kClass.primaryConstructor
                ?.parameters
                ?: error("Primary constructor not found for class ${kClass.simpleName}")

            kClass.declaredMemberProperties
                .filterNot { it.javaField?.isSynthetic == true }
                .onEach { it.isAccessible = true }
                .sortedBy { p.indexOfFirst { param -> param.name == it.name } }
        }

Cleaned up a little bit!

[Tech]

Haha, thank you.
There're so many extension functions that I don't know about