/* __ *\ ** ________ ___ / / ___ Scala API ** ** / __/ __// _ | / / / _ | (c) 2003-2013, LAMP/EPFL ** ** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** ** /____/\___/_/ |_/____/_/ | | ** ** |/ ** \* */ package scala.collection package immutable import generic._ /** * A generic trait for immutable maps. Concrete classes have to provide * functionality for the abstract methods in `Map`: * * {{{ * def get(key: A): Option[B] * def iterator: Iterator[(A, B)] * def + [B1 >: B](kv: (A, B1)): Map[A, B1] * def -(key: A): Map[A, B] * }}} * * @since 1 */ trait Map[A, +B] extends Iterable[(A, B)] // with GenMap[A, B] with scala.collection.Map[A, B] with MapLike[A, B, Map[A, B]] { self => override def empty: Map[A, B] = Map.empty override def toMap[T, U](implicit ev: (A, B) <:< (T, U)): immutable.Map[T, U] = self.asInstanceOf[immutable.Map[T, U]] override def seq: Map[A, B] = this /** The same map with a given default function. * Note: `get`, `contains`, `iterator`, `keys`, etc are not affected by `withDefault`. * * Invoking transformer methods (e.g. `map`) will not preserve the default value. * * @param d the function mapping keys to values, used for non-present keys * @return a wrapper of the map with a default value */ def withDefault[B1 >: B](d: A => B1): immutable.Map[A, B1] = new Map.WithDefault[A, B1](this, d) /** The same map with a given default value. * Note: `get`, `contains`, `iterator`, `keys`, etc are not affected by `withDefaultValue`. * * Invoking transformer methods (e.g. `map`) will not preserve the default value. * * @param d the function mapping keys to values, used for non-present keys * @return a wrapper of the map with a default value */ def withDefaultValue[B1 >: B](d: B1): immutable.Map[A, B1] = new Map.WithDefault[A, B1](this, x => d) /** Add a key/value pair to this map. * @param key the key * @param value the value * @return A new map with the new binding added to this map */ override def updated [B1 >: B](key: A, value: B1): Map[A, B1] def + [B1 >: B](kv: (A, B1)): Map[A, B1] } /** $factoryInfo * @define Coll `immutable.Map` * @define coll immutable map */ object Map extends ImmutableMapFactory[Map] { /** $mapCanBuildFromInfo */ implicit def canBuildFrom[A, B]: CanBuildFrom[Coll, (A, B), Map[A, B]] = new MapCanBuildFrom[A, B] def empty[A, B]: Map[A, B] = EmptyMap.asInstanceOf[Map[A, B]] class WithDefault[A, +B](underlying: Map[A, B], d: A => B) extends scala.collection.Map.WithDefault[A, B](underlying, d) with Map[A, B] { override def empty = new WithDefault(underlying.empty, d) override def updated[B1 >: B](key: A, value: B1): WithDefault[A, B1] = new WithDefault[A, B1](underlying.updated[B1](key, value), d) override def + [B1 >: B](kv: (A, B1)): WithDefault[A, B1] = updated(kv._1, kv._2) override def - (key: A): WithDefault[A, B] = new WithDefault(underlying - key, d) override def withDefault[B1 >: B](d: A => B1): immutable.Map[A, B1] = new WithDefault[A, B1](underlying, d) override def withDefaultValue[B1 >: B](d: B1): immutable.Map[A, B1] = new WithDefault[A, B1](underlying, x => d) } private object EmptyMap extends AbstractMap[Any, Nothing] with Map[Any, Nothing] with Serializable { override def size: Int = 0 def get(key: Any): Option[Nothing] = None def iterator: Iterator[(Any, Nothing)] = Iterator.empty override def updated [B1] (key: Any, value: B1): Map[Any, B1] = new Map1(key, value) def + [B1](kv: (Any, B1)): Map[Any, B1] = updated(kv._1, kv._2) def - (key: Any): Map[Any, Nothing] = this } class Map1[A, +B](key1: A, value1: B) extends AbstractMap[A, B] with Map[A, B] with Serializable { override def size = 1 def get(key: A): Option[B] = if (key == key1) Some(value1) else None def iterator = Iterator((key1, value1)) override def updated [B1 >: B] (key: A, value: B1): Map[A, B1] = if (key == key1) new Map1(key1, value) else new Map2(key1, value1, key, value) def + [B1 >: B](kv: (A, B1)): Map[A, B1] = updated(kv._1, kv._2) def - (key: A): Map[A, B] = if (key == key1) Map.empty else this override def foreach[U](f: ((A, B)) => U): Unit = { f((key1, value1)) } } class Map2[A, +B](key1: A, value1: B, key2: A, value2: B) extends AbstractMap[A, B] with Map[A, B] with Serializable { override def size = 2 def get(key: A): Option[B] = if (key == key1) Some(value1) else if (key == key2) Some(value2) else None def iterator = Iterator((key1, value1), (key2, value2)) override def updated [B1 >: B] (key: A, value: B1): Map[A, B1] = if (key == key1) new Map2(key1, value, key2, value2) else if (key == key2) new Map2(key1, value1, key2, value) else new Map3(key1, value1, key2, value2, key, value) def + [B1 >: B](kv: (A, B1)): Map[A, B1] = updated(kv._1, kv._2) def - (key: A): Map[A, B] = if (key == key1) new Map1(key2, value2) else if (key == key2) new Map1(key1, value1) else this override def foreach[U](f: ((A, B)) => U): Unit = { f((key1, value1)); f((key2, value2)) } } class Map3[A, +B](key1: A, value1: B, key2: A, value2: B, key3: A, value3: B) extends AbstractMap[A, B] with Map[A, B] with Serializable { override def size = 3 def get(key: A): Option[B] = if (key == key1) Some(value1) else if (key == key2) Some(value2) else if (key == key3) Some(value3) else None def iterator = Iterator((key1, value1), (key2, value2), (key3, value3)) override def updated [B1 >: B] (key: A, value: B1): Map[A, B1] = if (key == key1) new Map3(key1, value, key2, value2, key3, value3) else if (key == key2) new Map3(key1, value1, key2, value, key3, value3) else if (key == key3) new Map3(key1, value1, key2, value2, key3, value) else new Map4(key1, value1, key2, value2, key3, value3, key, value) def + [B1 >: B](kv: (A, B1)): Map[A, B1] = updated(kv._1, kv._2) def - (key: A): Map[A, B] = if (key == key1) new Map2(key2, value2, key3, value3) else if (key == key2) new Map2(key1, value1, key3, value3) else if (key == key3) new Map2(key1, value1, key2, value2) else this override def foreach[U](f: ((A, B)) => U): Unit = { f((key1, value1)); f((key2, value2)); f((key3, value3)) } } class Map4[A, +B](key1: A, value1: B, key2: A, value2: B, key3: A, value3: B, key4: A, value4: B) extends AbstractMap[A, B] with Map[A, B] with Serializable { override def size = 4 def get(key: A): Option[B] = if (key == key1) Some(value1) else if (key == key2) Some(value2) else if (key == key3) Some(value3) else if (key == key4) Some(value4) else None def iterator = Iterator((key1, value1), (key2, value2), (key3, value3), (key4, value4)) override def updated [B1 >: B] (key: A, value: B1): Map[A, B1] = if (key == key1) new Map4(key1, value, key2, value2, key3, value3, key4, value4) else if (key == key2) new Map4(key1, value1, key2, value, key3, value3, key4, value4) else if (key == key3) new Map4(key1, value1, key2, value2, key3, value, key4, value4) else if (key == key4) new Map4(key1, value1, key2, value2, key3, value3, key4, value) else new HashMap + ((key1, value1), (key2, value2), (key3, value3), (key4, value4), (key, value)) def + [B1 >: B](kv: (A, B1)): Map[A, B1] = updated(kv._1, kv._2) def - (key: A): Map[A, B] = if (key == key1) new Map3(key2, value2, key3, value3, key4, value4) else if (key == key2) new Map3(key1, value1, key3, value3, key4, value4) else if (key == key3) new Map3(key1, value1, key2, value2, key4, value4) else if (key == key4) new Map3(key1, value1, key2, value2, key3, value3) else this override def foreach[U](f: ((A, B)) => U): Unit = { f((key1, value1)); f((key2, value2)); f((key3, value3)); f((key4, value4)) } } } /** Explicit instantiation of the `Map` trait to reduce class file size in subclasses. */ private[scala] abstract class AbstractMap[A, +B] extends scala.collection.AbstractMap[A, B] with Map[A, B]