kotlin.enums.EnumEntries.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package kotlin.enums
import java.io.Serializable
/**
* A specialized immutable implementation of [List] interface that
* contains all enum entries of the specified enum type [E].
* [EnumEntries] contains all enum entries in the order they are declared in the source code,
* consistently with the corresponding [Enum.ordinal] values.
*
* An instance of this interface can only be obtained from `EnumClass.entries` property.
*/
@ExperimentalStdlibApi
interface EnumEntries> : List
@Suppress("unused")
@PublishedApi
@ExperimentalStdlibApi
internal fun > enumEntries(entriesProvider: () -> Array): EnumEntries = EnumEntriesList(entriesProvider())
@PublishedApi
@ExperimentalStdlibApi
internal fun > enumEntries(entries: Array): EnumEntries = EnumEntriesList(entries)
@ExperimentalStdlibApi
private class EnumEntriesList>(private val entries: Array) : EnumEntries, AbstractList(), Serializable {
// WA for JS IR bug:
// class type parameter name MUST be different from E (AbstractList type parameter),
// otherwise the bridge names for contains() and indexOf() will be clashed with the original method names,
// and produced JS code will not contain type checks and will not work correctly.
override val size: Int
get() = entries.size
override fun get(index: Int): T {
checkElementIndex(index, entries.size)
return entries[index]
}
// Ported from kotlin-stdlib-common AbstractList.kt
private fun checkElementIndex(index: Int, size: Int) {
if (index < 0 || index >= size) {
throw IndexOutOfBoundsException("index: $index, size: $size")
}
}
// By definition, EnumEntries contains **all** enums in declaration order,
// thus we are able to short-circuit the implementation here
override fun contains(element: T): Boolean {
@Suppress("SENSELESS_COMPARISON")
if (element === null) return false // WA for JS IR bug
// Check identity due to UnsafeVariance
val target = entries.getOrNull(element.ordinal)
return target === element
}
override fun indexOf(element: T): Int {
@Suppress("SENSELESS_COMPARISON")
if (element === null) return -1 // WA for JS IR bug
// Check identity due to UnsafeVariance
val ordinal = element.ordinal
val target = entries.getOrNull(ordinal)
return if (target === element) ordinal else -1
}
override fun lastIndexOf(element: T): Int = indexOf(element)
@Suppress("unused")
private fun writeReplace(): Any {
// Used for Java serialization: EESP ensures that deserialized object **always** reflects the state of the enum on the target classpath
return EnumEntriesSerializationProxy(entries)
}
}