This is the documentation for the Scala standard library. == Package structure == The [[scala]] package contains core types like [[scala.Int `Int`]], [[scala.Float `Float`]], [[scala.Array `Array`]] or [[scala.Option `Option`]] which are accessible in all Scala compilation units without explicit qualification or imports. Notable packages include: - [[scala.collection `scala.collection`]] and its sub-packages contain Scala's collections framework - [[scala.collection.immutable `scala.collection.immutable`]] - Immutable, sequential data-structures such as [[scala.collection.immutable.Vector `Vector`]], [[scala.collection.immutable.List `List`]], [[scala.collection.immutable.Range `Range`]], [[scala.collection.immutable.HashMap `HashMap`]] or [[scala.collection.immutable.HashSet `HashSet`]] - [[scala.collection.mutable `scala.collection.mutable`]] - Mutable, sequential data-structures such as [[scala.collection.mutable.ArrayBuffer `ArrayBuffer`]], [[scala.collection.mutable.StringBuilder `StringBuilder`]], [[scala.collection.mutable.HashMap `HashMap`]] or [[scala.collection.mutable.HashSet `HashSet`]] - [[scala.collection.concurrent `scala.collection.concurrent`]] - Mutable, concurrent data-structures such as [[scala.collection.concurrent.TrieMap `TrieMap`]] - [[scala.collection.parallel.immutable `scala.collection.parallel.immutable`]] - Immutable, parallel data-structures such as [[scala.collection.parallel.immutable.ParVector `ParVector`]], [[scala.collection.parallel.immutable.ParRange `ParRange`]], [[scala.collection.parallel.immutable.ParHashMap `ParHashMap`]] or [[scala.collection.parallel.immutable.ParHashSet `ParHashSet`]] - [[scala.collection.parallel.mutable `scala.collection.parallel.mutable`]] - Mutable, parallel data-structures such as [[scala.collection.parallel.mutable.ParArray `ParArray`]], [[scala.collection.parallel.mutable.ParHashMap `ParHashMap`]], [[scala.collection.parallel.mutable.ParTrieMap `ParTrieMap`]] or [[scala.collection.parallel.mutable.ParHashSet `ParHashSet`]] - [[scala.concurrent `scala.concurrent`]] - Primitives for concurrent programming such as [[scala.concurrent.Future `Futures`]] and [[scala.concurrent.Promise `Promises`]] - [[scala.io `scala.io`]] - Input and output operations - [[scala.math `scala.math`]] - Basic math functions and additional numeric types like [[scala.math.BigInt `BigInt`]] and [[scala.math.BigDecimal `BigDecimal`]] - [[scala.sys `scala.sys`]] - Interaction with other processes and the operating system - [[scala.util.matching `scala.util.matching`]] - [[scala.util.matching.Regex Regular expressions]] Other packages exist. See the complete list on the left. Additional parts of the standard library are shipped as separate libraries. These include: - [[scala.reflect `scala.reflect`]] - Scala's reflection API (scala-reflect.jar) - [[scala.xml `scala.xml`]] - XML parsing, manipulation, and serialization (scala-xml.jar) - [[scala.swing `scala.swing`]] - A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar) - [[scala.util.continuations `scala.util.continuations`]] - Delimited continuations using continuation-passing-style (scala-continuations-library.jar, scala-continuations-plugin.jar) - [[scala.util.parsing `scala.util.parsing`]] - [[scala.util.parsing.combinator Parser combinators]], including an example implementation of a [[scala.util.parsing.json JSON parser]] (scala-parser-combinators.jar) - [[scala.actors `scala.actors`]] - Actor-based concurrency (deprecated and replaced by Akka actors, scala-actors.jar) == Automatic imports == Identifiers in the scala package and the [[scala.Predef `scala.Predef`]] object are always in scope by default. Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example, `List` is an alias for [[scala.collection.immutable.List `scala.collection.immutable.List`]]. Other aliases refer to classes provided by the underlying platform. For example, on the JVM, `String` is an alias for `java.lang.String`.