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Standard library for the Scala Programming Language
/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package scala
package collection
package convert
import java.util.{concurrent => juc}
import java.{lang => jl, util => ju}
/** Defines converter methods from Java to Scala collections.
* These methods are available through the [[scala.jdk.javaapi.CollectionConverters]] object.
*/
trait AsScalaConverters {
import JavaCollectionWrappers._
/**
* Converts a Java `Iterator` to a Scala `Iterator`.
*
* The returned Scala `Iterator` is backed by the provided Java `Iterator` and any side-effects of
* using it via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `Iterator` was previously obtained from an implicit or explicit call of
* `asJava` then the original Scala `Iterator` will be returned.
*
* @param i The Java `Iterator` to be converted.
* @return A Scala `Iterator` view of the argument.
*/
def asScala[A](i: ju.Iterator[A]): Iterator[A] = i match {
case null => null
case IteratorWrapper(wrapped) => wrapped
case _ => JIteratorWrapper(i)
}
/**
* Converts a Java `Enumeration` to a Scala `Iterator`.
*
* The returned Scala `Iterator` is backed by the provided Java `Enumeration` and any side-effects
* of using it via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `Enumeration` was previously obtained from an implicit or explicit call of
* `asJavaEnumeration` then the original Scala `Iterator` will be returned.
*
* @param e The Java `Enumeration` to be converted.
* @return A Scala `Iterator` view of the argument.
*/
def asScala[A](e: ju.Enumeration[A]): Iterator[A] = e match {
case null => null
case IteratorWrapper(wrapped) => wrapped
case _ => JEnumerationWrapper(e)
}
/**
* Converts a Java `Iterable` to a Scala `Iterable`.
*
* The returned Scala `Iterable` is backed by the provided Java `Iterable` and any side-effects of
* using it via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `Iterable` was previously obtained from an implicit or explicit call of
* `asJava` then the original Scala `Iterable` will be returned.
*
* @param i The Java `Iterable` to be converted.
* @return A Scala `Iterable` view of the argument.
*/
def asScala[A](i: jl.Iterable[A]): Iterable[A] = i match {
case null => null
case IterableWrapper(wrapped) => wrapped
case _ => JIterableWrapper(i)
}
/**
* Converts a Java `Collection` to a Scala `Iterable`.
*
* If the Java `Collection` was previously obtained from an implicit or explicit call of
* `asJavaCollection` then the original Scala `Iterable` will be returned.
*
* @param c The Java `Collection` to be converted.
* @return A Scala `Iterable` view of the argument.
*/
def asScala[A](c: ju.Collection[A]): Iterable[A] = c match {
case null => null
case IterableWrapper(wrapped) => wrapped
case _ => JCollectionWrapper(c)
}
/**
* Converts a Java `List` to a Scala mutable `Buffer`.
*
* The returned Scala `Buffer` is backed by the provided Java `List` and any side-effects of using
* it via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `List` was previously obtained from an implicit or explicit call of
* `asJava` then the original Scala `Buffer` will be returned.
*
* @param l The Java `List` to be converted.
* @return A Scala mutable `Buffer` view of the argument.
*/
def asScala[A](l: ju.List[A]): mutable.Buffer[A] = l match {
case null => null
case MutableBufferWrapper(wrapped) => wrapped
case _ => new JListWrapper(l)
}
/**
* Converts a Java `Set` to a Scala mutable `Set`.
*
* The returned Scala `Set` is backed by the provided Java `Set` and any side-effects of using it
* via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `Set` was previously obtained from an implicit or explicit call of
* `asJava` then the original Scala `Set` will be returned.
*
* @param s The Java `Set` to be converted.
* @return A Scala mutable `Set` view of the argument.
*/
def asScala[A](s: ju.Set[A]): mutable.Set[A] = s match {
case null => null
case MutableSetWrapper(wrapped) => wrapped
case _ => new JSetWrapper(s)
}
/**
* Converts a Java `Map` to a Scala mutable `Map`.
*
* The returned Scala `Map` is backed by the provided Java `Map` and any side-effects of using it
* via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `Map` was previously obtained from an implicit or explicit call of
* `asJava` then the original Scala `Map` will be returned.
*
* If the wrapped map is synchronized (e.g. from `java.util.Collections.synchronizedMap`), it is
* your responsibility to wrap all non-atomic operations with `underlying.synchronized`.
* This includes `get`, as `java.util.Map`'s API does not allow for an atomic `get` when `null`
* values may be present.
*
* @param m The Java `Map` to be converted.
* @return A Scala mutable `Map` view of the argument.
*/
def asScala[A, B](m: ju.Map[A, B]): mutable.Map[A, B] = m match {
case null => null
case MutableMapWrapper(wrapped) => wrapped
case _ => new JMapWrapper(m)
}
/**
* Converts a Java `ConcurrentMap` to a Scala mutable `ConcurrentMap`.
*
* The returned Scala `ConcurrentMap` is backed by the provided Java `ConcurrentMap` and any
* side-effects of using it via the Scala interface will be visible via the Java interface and
* vice versa.
*
* If the Java `ConcurrentMap` was previously obtained from an implicit or explicit call of
* `asJava` then the original Scala `ConcurrentMap` will be returned.
*
* @param m The Java `ConcurrentMap` to be converted.
* @return A Scala mutable `ConcurrentMap` view of the argument.
*/
def asScala[A, B](m: juc.ConcurrentMap[A, B]): concurrent.Map[A, B] = m match {
case null => null
case cmw: ConcurrentMapWrapper[_, _] => cmw.underlying
case _ => new JConcurrentMapWrapper(m)
}
/**
* Converts a Java `Dictionary` to a Scala mutable `Map`.
*
* The returned Scala `Map` is backed by the provided Java `Dictionary` and any side-effects of
* using it via the Scala interface will be visible via the Java interface and vice versa.
*
* If the Java `Dictionary` was previously obtained from an implicit or explicit call of
* `asJavaDictionary` then the original Scala `Map` will be returned.
*
* @param d The Java `Dictionary` to be converted.
* @return A Scala mutable `Map` view of the argument.
*/
def asScala[A, B](d: ju.Dictionary[A, B]): mutable.Map[A, B] = d match {
case null => null
case DictionaryWrapper(wrapped) => wrapped
case _ => new JDictionaryWrapper(d)
}
/**
* Converts a Java `Properties` to a Scala mutable `Map[String, String]`.
*
* The returned Scala `Map[String, String]` is backed by the provided Java `Properties` and any
* side-effects of using it via the Scala interface will be visible via the Java interface and
* vice versa.
*
* @param p The Java `Properties` to be converted.
* @return A Scala mutable `Map[String, String]` view of the argument.
*/
def asScala(p: ju.Properties): mutable.Map[String, String] = p match {
case null => null
case _ => new JPropertiesWrapper(p)
}
}