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muza/app/src/main/kotlin/it/vfsfitvnm/vimusic/savers/Savers.kt

38 lines
1.5 KiB
Kotlin

package it.vfsfitvnm.vimusic.savers
import androidx.compose.runtime.saveable.Saver
import androidx.compose.runtime.saveable.SaverScope
interface ListSaver<Original, Saveable : Any> : Saver<List<Original>, List<Saveable>> {
override fun SaverScope.save(value: List<Original>): List<Saveable>
override fun restore(value: List<Saveable>): List<Original>
}
fun <Original, Saveable : Any> resultSaver(saver: Saver<Original, Saveable>) =
object : Saver<Result<Original>?, Pair<Saveable?, Throwable?>> {
override fun restore(value: Pair<Saveable?, Throwable?>) =
value.first?.let(saver::restore)?.let(Result.Companion::success)
?: value.second?.let(Result.Companion::failure)
override fun SaverScope.save(value: Result<Original>?) =
with(saver) { value?.getOrNull()?.let { save(it) } } to value?.exceptionOrNull()
}
fun <Original, Saveable : Any> listSaver(saver: Saver<Original, Saveable>) =
object : ListSaver<Original, Saveable> {
override fun restore(value: List<Saveable>) =
value.mapNotNull(saver::restore)
override fun SaverScope.save(value: List<Original>) =
with(saver) { value.mapNotNull { save(it) } }
}
fun <Original, Saveable : Any> nullableSaver(saver: Saver<Original, Saveable>) =
object : Saver<Original?, Saveable> {
override fun SaverScope.save(value: Original?): Saveable? =
value?.let { with(saver) { save(it) } }
override fun restore(value: Saveable): Original? =
saver.restore(value)
}