kotlin.collections.MapsJVM.kt Maven / Gradle / Ivy

Go to download
@file:kotlin.jvm.JvmMultifileClass
@file:kotlin.jvm.JvmName("MapsKt")

package kotlin.collections

import java.util.Comparator
import java.util.LinkedHashMap
import java.util.Properties
import java.util.SortedMap
import java.util.TreeMap
import java.util.concurrent.ConcurrentMap

/**
 * Allows to use the index operator for storing values in a mutable map.
 */
// this code is JVM-specific, because JS has native set function
@kotlin.internal.InlineOnly
public inline operator fun  MutableMap.set(key: K, value: V): Unit {
    put(key, value)
}

/**
 * Concurrent getOrPut, that is safe for concurrent maps.
 *
 * Returns the value for the given [key]. If the key is not found in the map, calls the [defaultValue] function,
 * puts its result into the map under the given key and returns it.
 *
 * This method guarantees not to put the value into the map if the key is already there,
 * but the [defaultValue] function may be invoked even if the key is already in the map.
 */
public inline fun  ConcurrentMap.getOrPut(key: K, defaultValue: () -> V): V {
    // Do not use computeIfAbsent on JVM8 as it would change locking behavior
    return this.get(key) ?:
            defaultValue().let { default -> this.putIfAbsent(key, default) ?: default }

}


/**
 * Converts this [Map] to a [SortedMap] so iteration order will be in key order.
 *
 * @sample test.collections.MapJVMTest.toSortedMap
 */
public fun , V> Map.toSortedMap(): SortedMap = TreeMap(this)

/**
 * Converts this [Map] to a [SortedMap] using the given [comparator] so that iteration order will be in the order
 * defined by the comparator.
 *
 * @sample test.collections.MapJVMTest.toSortedMapWithComparator
 */
public fun  Map.toSortedMap(comparator: Comparator): SortedMap
        = TreeMap(comparator).apply { putAll(this@toSortedMap) }

/**
 * Returns a new [SortedMap] with the specified contents, given as a list of pairs
 * where the first value is the key and the second is the value.
 *
 * @sample test.collections.MapJVMTest.createSortedMap
 */
public fun , V> sortedMapOf(vararg pairs: Pair): SortedMap
        = TreeMap().apply { putAll(pairs) }


/**
 * Converts this [Map] to a [Properties] object.
 *
 * @sample test.collections.MapJVMTest.toProperties
 */
@kotlin.internal.InlineOnly
public inline fun Map.toProperties(): Properties
        = Properties().apply { putAll(this@toProperties) }