diff options
Diffstat (limited to 'src/library/scala/collection/immutable/MapLike.scala')
| -rw-r--r-- | src/library/scala/collection/immutable/MapLike.scala | 55 |
1 files changed, 27 insertions, 28 deletions
diff --git a/src/library/scala/collection/immutable/MapLike.scala b/src/library/scala/collection/immutable/MapLike.scala index bd5b9c9faf..5867383b52 100644 --- a/src/library/scala/collection/immutable/MapLike.scala +++ b/src/library/scala/collection/immutable/MapLike.scala @@ -14,16 +14,16 @@ import generic._ import parallel.immutable.ParMap /** - * A generic template for immutable maps from keys of type `A` - * to values of type `B`. + * A generic template for immutable maps from keys of type `K` + * to values of type `V`. * To implement a concrete map, you need to provide implementations of the * following methods (where `This` is the type of the actual map implementation): * * {{{ - * def get(key: A): Option[B] - * def iterator: Iterator[(A, B)] - * def + [B1 >: B](kv: (A, B)): Map[A, B1] - * def - (key: A): This + * def get(key: K): Option[V] + * def iterator: Iterator[(K, V)] + * def + [V1 >: V](kv: (K, V)): Map[K, V1] + * def - (key: K): This * }}} * * If you wish that transformer methods like `take`, `drop`, `filter` return the @@ -36,8 +36,8 @@ import parallel.immutable.ParMap * It is also good idea to override methods `foreach` and * `size` for efficiency. * - * @tparam A the type of the keys contained in this collection. - * @tparam B the type of the values associated with the keys. + * @tparam K the type of the keys contained in this collection. + * @tparam V the type of the values associated with the keys. * @tparam This The type of the actual map implementation. * * @author Martin Odersky @@ -46,26 +46,26 @@ import parallel.immutable.ParMap * @define Coll immutable.Map * @define coll immutable map */ -trait MapLike[A, +B, +This <: MapLike[A, B, This] with Map[A, B]] - extends scala.collection.MapLike[A, B, This] - with Parallelizable[(A, B), ParMap[A, B]] +trait MapLike[K, +V, +This <: MapLike[K, V, This] with Map[K, V]] + extends scala.collection.MapLike[K, V, This] + with Parallelizable[(K, V), ParMap[K, V]] { self => - protected[this] override def parCombiner = ParMap.newCombiner[A, B] + protected[this] override def parCombiner = ParMap.newCombiner[K, V] /** A new immutable map containing updating this map with a given key/value mapping. * @param key the key * @param value the value * @return A new map with the new key/value mapping */ - override def updated [B1 >: B](key: A, value: B1): immutable.Map[A, B1] = this + ((key, value)) + override def updated [V1 >: V](key: K, value: V1): immutable.Map[K, V1] = this + ((key, value)) /** Add a key/value pair to this map, returning a new map. * @param kv the key/value pair. * @return A new map with the new binding added to this map. */ - def + [B1 >: B] (kv: (A, B1)): immutable.Map[A, B1] + def + [V1 >: V] (kv: (K, V1)): immutable.Map[K, V1] /** Adds two or more elements to this collection and returns * a new collection. @@ -75,7 +75,7 @@ self => * @param elems the remaining elements to add. * @return A new map with the new bindings added to this map. */ - override def + [B1 >: B] (elem1: (A, B1), elem2: (A, B1), elems: (A, B1) *): immutable.Map[A, B1] = + override def + [V1 >: V] (elem1: (K, V1), elem2: (K, V1), elems: (K, V1) *): immutable.Map[K, V1] = this + elem1 + elem2 ++ elems /** Adds a number of elements provided by a traversable object @@ -84,40 +84,40 @@ self => * @param xs the traversable object consisting of key-value pairs. * @return a new immutable map with the bindings of this map and those from `xs`. */ - override def ++[B1 >: B](xs: GenTraversableOnce[(A, B1)]): immutable.Map[A, B1] = - ((repr: immutable.Map[A, B1]) /: xs.seq) (_ + _) + override def ++[V1 >: V](xs: GenTraversableOnce[(K, V1)]): immutable.Map[K, V1] = + ((repr: immutable.Map[K, V1]) /: xs.seq) (_ + _) /** Filters this map by retaining only keys satisfying a predicate. * @param p the predicate used to test keys * @return an immutable map consisting only of those key value pairs of this map where the key satisfies * the predicate `p`. The resulting map wraps the original map without copying any elements. */ - override def filterKeys(p: A => Boolean): Map[A, B] = new FilteredKeys(p) with DefaultMap[A, B] + override def filterKeys(p: K => Boolean): Map[K, V] = new FilteredKeys(p) with DefaultMap[K, V] /** Transforms this map by applying a function to every retrieved value. * @param f the function used to transform values of this map. * @return a map view which maps every key of this map * to `f(this(key))`. The resulting map wraps the original map without copying any elements. */ - override def mapValues[C](f: B => C): Map[A, C] = new MappedValues(f) with DefaultMap[A, C] + override def mapValues[W](f: V => W): Map[K, W] = new MappedValues(f) with DefaultMap[K, W] /** Collects all keys of this map in a set. * @return a set containing all keys of this map. */ - override def keySet: immutable.Set[A] = new ImmutableDefaultKeySet + override def keySet: immutable.Set[K] = new ImmutableDefaultKeySet - protected class ImmutableDefaultKeySet extends super.DefaultKeySet with immutable.Set[A] { - override def + (elem: A): immutable.Set[A] = + protected class ImmutableDefaultKeySet extends super.DefaultKeySet with immutable.Set[K] { + override def + (elem: K): immutable.Set[K] = if (this(elem)) this - else immutable.Set[A]() ++ this + elem - override def - (elem: A): immutable.Set[A] = - if (this(elem)) immutable.Set[A]() ++ this - elem + else immutable.Set[K]() ++ this + elem + override def - (elem: K): immutable.Set[K] = + if (this(elem)) immutable.Set[K]() ++ this - elem else this // ImmutableDefaultKeySet is only protected, so we won't warn on override. // Someone could override in a way that makes widening not okay // (e.g. by overriding +, though the version in this class is fine) - override def toSet[B >: A]: Set[B] = this.asInstanceOf[Set[B]] + override def toSet[B >: K]: Set[B] = this.asInstanceOf[Set[B]] } /** This function transforms all the values of mappings contained @@ -126,10 +126,9 @@ self => * @param f A function over keys and values * @return the updated map */ - def transform[C, That](f: (A, B) => C)(implicit bf: CanBuildFrom[This, (A, C), That]): That = { + def transform[W, That](f: (K, V) => W)(implicit bf: CanBuildFrom[This, (K, W), That]): That = { val b = bf(repr) for ((key, value) <- this) b += ((key, f(key, value))) b.result() } } - |