Adds a single element to this multimap.

Optionally returns the value associated with a key.

An scala.collection.Iterator over the elements of this multimap.

If an IterableOnce object is in fact an scala.collection.Iterator, this method always returns itself, in its current state, but if it is an scala.collection.Iterable, this method always returns a new scala.collection.Iterator.

Removes a single element from this multimap.

Test two objects for inequality.

Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

Alias for concat

Alias for concat

Alias for addAll

Alias for addOne

Alias for subtractAll

Alias for subtractOne

The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

Adds all elements produced by an IterableOnce to this multimap.

Assigns the specified value to a specified key. If the key already has a binding to equal to value, nothing is changed; otherwise a new binding is added for that key.

Appends all elements of this multimap to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this multimap are separated by the string sep.

Example:

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> a.addString(b , "List(" , ", " , ")")
res5: StringBuilder = List(1, 2, 3, 4)

Appends all elements of this multimap to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this multimap without any separator string.

Example:

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> val h = a.addString(b)
h: StringBuilder = 1234

Appends all elements of this multimap to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method toString) of all elements of this multimap, separated by the string sep.

Example:

scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> a.addString(b, ", ")
res0: StringBuilder = 1, 2, 3, 4

Composes this partial function with another partial function that gets applied to results of this partial function.

Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.

Composes this partial function with a transformation function that gets applied to results of this partial function.

If the runtime type of the function is a PartialFunction then the other andThen method is used (note its cautions).

Retrieves the value which is associated with the given key. This method invokes the default method of the map if there is no mapping from the given key to a value. Unless overridden, the default method throws a NoSuchElementException.

Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.

Note that expression pf.applyOrElse(x, default) is equivalent to

if(pf isDefinedAt x) pf(x) else default(x)

except that applyOrElse method can be implemented more efficiently. For all partial function literals the compiler generates an applyOrElse implementation which avoids double evaluation of pattern matchers and guards. This makes applyOrElse the basis for the efficient implementation for many operations and scenarios, such as:

• combining partial functions into orElse/andThen chains does not lead to excessive apply/isDefinedAt evaluation
• lift and unlift do not evaluate source functions twice on each invocation
• runWith allows efficient imperative-style combining of partial functions with conditionally applied actions

For non-literal partial function classes with nontrivial isDefinedAt method it is recommended to override applyOrElse with custom implementation that avoids double isDefinedAt evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.

Cast the receiver object to be of type T0.

Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

Checks whether this instance can possibly equal that.

A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.

Defines the prefix of this object's toString representation.

It is recommended to return the name of the concrete collection type, but not implementation subclasses. For example, for ListMap this method should return "ListMap", not "Map" (the supertype) or "Node" (an implementation subclass).

The default implementation returns "Iterable". It is overridden for the basic collection kinds "Seq", "IndexedSeq", "LinearSeq", "Buffer", "Set", "Map", "SortedSet", "SortedMap" and "View".

Clears the contents of this builder. After execution of this method the builder will contain no elements.

Create a copy of the receiver object.

The default implementation of the clone method is platform dependent.

Builds a new collection by applying a partial function to all elements of this multimap on which the function is defined.

Builds a new multimap by applying a partial function to all elements of this multimap on which the function is defined.

Finds the first element of the multimap for which the given partial function is defined, and applies the partial function to it.

Note: may not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Composes another partial function k with this partial function so that this partial function gets applied to results of k.

Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.

Composes two instances of Function1 in a new Function1, with this function applied last.

Returns a new multimap containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the multimap is the most specific superclass encompassing the element types of the two operands.

Returns a new multimap containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the multimap is the most specific superclass encompassing the element types of the two operands.

Tests whether this map contains a binding for a key.

Copy elements to an array, returning the number of elements written.

Fills the given array xs starting at index start with at most len elements of this multimap.

Copying will stop once either all the elements of this multimap have been copied, or the end of the array is reached, or len elements have been copied.

Copies elements to an array, returning the number of elements written.

Fills the given array xs starting at index start with values of this multimap.

Copying will stop once either all the elements of this multimap have been copied, or the end of the array is reached.

Copies elements to an array, returning the number of elements written.

Fills the given array xs starting at index start with values of this multimap.

Copying will stop once either all the elements of this multimap have been copied, or the end of the array is reached.

Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.

Note: will not terminate for infinite-sized collections.

Counts the number of elements in the multimap which satisfy a predicate.

Note: will not terminate for infinite-sized collections.

Defines the default value computation for the map, returned when a key is not found.

The method implemented here throws an exception, but it may be overridden by subclasses.

Selects all elements except the first n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Selects all elements except last n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Selects all elements except the longest prefix that satisfies a predicate.

The matching prefix starts with the first element of this multimap, and the element following the prefix is the first element that does not satisfy the predicate. The matching prefix may be empty, so that this method returns the entire multimap.

Example:

scala> List(1, 2, 3, 100, 4).dropWhile(n => n < 10)
val res0: List[Int] = List(100, 4)

scala> List(1, 2, 3, 100, 4).dropWhile(n => n == 0)
val res1: List[Int] = List(1, 2, 3, 100, 4)

Use span to obtain both the prefix and suffix. Use filterNot to drop all elements that satisfy the predicate.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Returns an extractor object with a unapplySeq method, which extracts each element of a sequence data.

The empty iterable of the same type as this iterable.

Checks if there exists a binding to key such that it satisfies the predicate p.

Tests whether the argument (that) is a reference to the receiver object (this).

The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

• It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
• For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
• null.eq(null) returns true.

When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

Equality of maps is implemented using the lookup method get. This method returns true if

• the argument o is a Map,
• the two maps have the same size, and
• for every (key, value) pair in this map, other.get(key) == Some(value).

The implementation of equals checks the canEqual method, so subclasses of Map can narrow down the equality to specific map types. The Map implementations in the standard library can all be compared, their canEqual methods return true.

Note: The equals method only respects the equality laws (symmetry, transitivity) if the two maps use the same key equivalence function in their lookup operation. For example, the key equivalence operation in a scala.collection.immutable.TreeMap is defined by its ordering. Comparing a TreeMap with a HashMap leads to unexpected results if ordering.equiv(k1, k2) (used for lookup in TreeMap) is different from k1 == k2 (used for lookup in HashMap).

scala> import scala.collection.immutable._
scala> val ord: Ordering[String] = _ compareToIgnoreCase _

scala> TreeMap("A" -> 1)(ord) == HashMap("a" -> 1)
val res0: Boolean = false

scala> HashMap("a" -> 1) == TreeMap("A" -> 1)(ord)
val res1: Boolean = true

Tests whether a predicate holds for at least one element of this multimap.

Note: may not terminate for infinite-sized collections.

Selects all elements of this multimap which satisfy a predicate.

Retains only those mappings for which the predicate p returns true.

Selects all elements of this multimap which do not satisfy a predicate.

Called by the garbage collector on the receiver object when there are no more references to the object.

The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

Finds the first element of the multimap satisfying a predicate, if any.

Note: may not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Builds a new map by applying a function to all elements of this multimap and using the elements of the resulting collections.

Builds a new multimap by applying a function to all elements of this multimap and using the elements of the resulting collections.

For example:

def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")

The type of the resulting collection is guided by the static type of multimap. This might cause unexpected results sometimes. For example:

// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set
def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet)

// lettersOf will return a Set[Char], not a Seq
def lettersOf(words: Seq[String]) = words.toSet flatMap ((word: String) => word.toSeq)

// xs will be an Iterable[Int]
val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2)

// ys will be a Map[Int, Int]
val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)

Converts this multimap of iterable collections into a multimap formed by the elements of these iterable collections.

The resulting collection's type will be guided by the type of multimap. For example:

val xs = List(
           Set(1, 2, 3),
           Set(1, 2, 3)
         ).flatten
// xs == List(1, 2, 3, 1, 2, 3)

val ys = Set(
           List(1, 2, 3),
           List(3, 2, 1)
         ).flatten
// ys == Set(1, 2, 3)

Applies the given binary operator op to the given initial value z and all elements of this multimap.

For each application of the operator, each operand is either an element of this multimap, the initial value, or another such application of the operator.

The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation. The initial value may be used an arbitrary number of times, but at least once.

If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.

Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative. In either case, it is also necessary that the initial value be a neutral value for the operator, e.g. Nil for List concatenation or 1 for multiplication.

The default implementation in IterableOnce is equivalent to foldLeft but may be overridden for more efficient traversal orders.

Note: will not terminate for infinite-sized collections.

Applies the given binary operator op to the given initial value z and all elements of this multimap, going left to right. Returns the initial value if this multimap is empty.

"Going left to right" only makes sense if this collection is ordered: then if x1, x2, ..., xn are the elements of this multimap, the result is op( op( ... op( op(z, x1), x2) ... ), xn).

If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the initial value, and each other left operand is itself an application of the operator. The elements of this multimap and the initial value all appear exactly once in the computation.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Note: will not terminate for infinite-sized collections.

Applies the given binary operator op to all elements of this multimap and the given initial value z, going right to left. Returns the initial value if this multimap is empty.

"Going right to left" only makes sense if this collection is ordered: then if x1, x2, ..., xn are the elements of this multimap, the result is op(x1, op(x2, op( ... op(xn, z) ... ))).

If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the initial value, and each other right operand is itself an application of the operator. The elements of this multimap and the initial value all appear exactly once in the computation.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Note: will not terminate for infinite-sized collections.

Tests whether a predicate holds for all elements of this multimap.

Note: may not terminate for infinite-sized collections.

Applies f to each element for its side effects. Note: U parameter needed to help scalac's type inference.

Apply f to each key/value pair for its side effects Note: [U] parameter needed to help scalac's type inference.

Defines how to turn a given Iterable[A] into a collection of type C.

This process can be done in a strict way or a non-strict way (ie. without evaluating the elements of the resulting collections). In other words, this methods defines the evaluation model of the collection.

Returns the runtime class representation of the object.

Returns the value associated with a key, or a default value if the key is not contained in the map.

If given key is already in this map, returns associated value.

Otherwise, computes value from given expression op, stores with key in map and returns that value.

Concurrent map implementations may evaluate the expression op multiple times, or may evaluate op without inserting the result.

Partitions this multimap into a map of multimaps according to some discriminator function.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Partitions this multimap into a map of multimaps according to a discriminator function key. Each element in a group is transformed into a value of type B using the value function.

It is equivalent to groupBy(key).mapValues(_.map(f)), but more efficient.

case class User(name: String, age: Int)

def namesByAge(users: Seq[User]): Map[Int, Seq[String]] =
  users.groupMap(_.age)(_.name)

Note: Even when applied to a view or a lazy collection it will always force the elements.

Partitions this multimap into a map according to a discriminator function key. All the values that have the same discriminator are then transformed by the f function and then reduced into a single value with the reduce function.

It is equivalent to groupBy(key).mapValues(_.map(f).reduce(reduce)), but more efficient.

def occurrences[A](as: Seq[A]): Map[A, Int] =
  as.groupMapReduce(identity)(_ => 1)(_ + _)

Note: Even when applied to a view or a lazy collection it will always force the elements.

Partitions elements in fixed size multimaps.

The hashCode method for reference types. See hashCode in scala.Any.

Selects the first element of this multimap.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Optionally selects the first element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

The initial part of the collection without its last element.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Iterates over the inits of this multimap. The first value will be this multimap and the final one will be an empty multimap, with the intervening values the results of successive applications of init.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Tests whether this map contains a binding for a key. This method, which implements an abstract method of trait PartialFunction, is equivalent to contains.

Tests whether the multimap is empty.

Note: The default implementation creates and discards an iterator.

Note: Implementations in subclasses that are not repeatedly iterable must take care not to consume any elements when isEmpty is called.

Test whether the dynamic type of the receiver object has the same erasure as T0.

Depending on what T0 is, the test is done in one of the below ways:

• T0 is a non-parameterized class type, e.g. BigDecimal: this method returns true if the value of the receiver object is a BigDecimal or a subtype of BigDecimal.
• T0 is a parameterized class type, e.g. List[Int]: this method returns true if the value of the receiver object is some List[X] for any X. For example, List(1, 2, 3).isInstanceOf[List[String]] will return true.
• T0 is some singleton type x.type or literal x: this method returns this.eq(x). For example, x.isInstanceOf[1] is equivalent to x.eq(1)
• T0 is an intersection X with Y or X & Y: this method is equivalent to x.isInstanceOf[X] && x.isInstanceOf[Y]
• T0 is a union X | Y: this method is equivalent to x.isInstanceOf[X] || x.isInstanceOf[Y]
• T0 is a type parameter or an abstract type member: this method is equivalent to isInstanceOf[U] where U is T0's upper bound, Any if T0 is unbounded. For example, x.isInstanceOf[A] where A is an unbounded type parameter will return true for any value of x.

This is exactly equivalent to the type pattern _: T0

Tests whether this multimap can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.

The companion object of this multimap, providing various factory methods.

A set representing the keys contained by this map.

For efficiency the resulting set may be a view (maintaining a reference to the map and reflecting modifications to the map), but it may also be a strict collection without reference to the map.

• To ensure an independent strict collection, use m.keysIterator.toSet
• To obtain a view on the keys, use scala.collection.View.fromIteratorProvider(m.keysIterator)

Returns a Stepper for the keys of this map. See method stepper.

An Iterable collection of the keys contained by this map.

For efficiency the resulting collection may be a view (maintaining a reference to the map and reflecting modifications to the map), but it may also be a strict collection without reference to the map.

• To ensure an independent strict collection, use m.keysIterator.toSet
• To obtain a view on the keys, use scala.collection.View.fromIteratorProvider(m.keysIterator)

An Iterator of the keys contained by this map.

The number of elements in the collection under construction, if it can be cheaply computed, -1 otherwise.

Selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Optionally selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Analogous to zip except that the elements in each collection are not consumed until a strict operation is invoked on the returned LazyZip2 decorator.

Calls to lazyZip can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.

val xs = List(1, 2, 3)
val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d)
// res == List(4, 8, 12)

Turns this partial function into a plain function returning an Option result.

Creates a new set.

Classes that use this trait as a mixin can override this method to have the desired implementation of sets assigned to new keys. By default this is HashSet.

Builds a new map by applying a function to all elements of this multimap.

Builds a new multimap by applying a function to all elements of this multimap.

The companion object of this map, providing various factory methods.

Similar to fromIterable, but returns a Map collection type. Note that the return type is now CC[K2, V2].

A builder resulting from this builder my mapping the result using f.

Applies a transformation function to all values contained in this map. The transformation function produces new values from existing keys associated values.

Finds the largest element.

Note: will not terminate for infinite-sized collections.

Finds the first element which yields the largest value measured by function f.

Note: will not terminate for infinite-sized collections.

Finds the first element which yields the largest value measured by function f.

Note: will not terminate for infinite-sized collections.

Finds the largest element.

Note: will not terminate for infinite-sized collections.

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

Finds the first element which yields the smallest value measured by function f.

Note: will not terminate for infinite-sized collections.

Finds the first element which yields the smallest value measured by function f.

Note: will not terminate for infinite-sized collections.

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

Displays all elements of this multimap in a string.

Delegates to addString, which can be overridden.

Displays all elements of this multimap in a string using a separator string.

Delegates to addString, which can be overridden.

Displays all elements of this multimap in a string using start, end, and separator strings.

Delegates to addString, which can be overridden.

Equivalent to !(this eq that).

Tests whether the multimap is not empty.

Wakes up a single thread that is waiting on the receiver object's monitor.

Wakes up all threads that are waiting on the receiver object's monitor.

Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.

A pair of, first, all elements that satisfy predicate p and, second, all elements that do not.

The two multimap correspond to the result of filter and filterNot, respectively.

The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of partition in StrictOptimizedIterableOps, which requires only a single traversal.

Applies a function f to each element of the multimap and returns a pair of multimaps: the first one made of those values returned by f that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

Example:

val xs = `MultiMap`(1, "one", 2, "two", 3, "three") partitionMap {
 case i: Int => Left(i)
 case s: String => Right(s)
}
// xs == (`MultiMap`(1, 2, 3),
//        `MultiMap`(one, two, three))

Multiplies together the elements of this collection.

The default implementation uses reduce for a known non-empty collection, foldLeft otherwise.

Note: will not terminate for infinite-sized collections.

Adds a new key/value pair to this map and optionally returns previously bound value. If the map already contains a mapping for the key, it will be overridden by the new value.

Applies the given binary operator op to all elements of this multimap.

For each application of the operator, each operand is either an element of this multimap or another such application of the operator. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.

If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.

Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

Applies the given binary operator op to all elements of this multimap, going left to right.

"Going left to right" only makes sense if this collection is ordered: then if x1, x2, ..., xn are the elements of this multimap, the result is op( op( op( ... op(x1, x2) ... ), xn-1), xn).

If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the first element of this multimap and each other left operand is itself an application of the operator. Each element appears exactly once in the computation.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

If this multimap is nonempty, reduces it with the given binary operator op, going left to right.

The behavior is the same as reduceLeft except that the value is None if the multimap is empty. Each element appears exactly once in the computation.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

If this multimap is nonempty, reduces it with the given binary operator op.

The behavior is the same as reduce except that the value is None if the multimap is empty. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.

Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

Applies the given binary operator op to all elements of this multimap, going right to left.

"Going right to left" only makes sense if this collection is ordered: then if x1, x2, ..., xn are the elements of this multimap, the result is op(x1, op(x2, op( ... op(xn-1, xn) ... ))).

If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the last element of this multimap and each other right operand is itself an application of the operator. Each element appears exactly once in the computation.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

If this multimap is nonempty, reduces it with the given binary operator op, going right to left.

The behavior is the same as reduceRight except that the value is None if the multimap is empty. Each element appears exactly once in the computation.

Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

Removes a key from this map, returning the value associated previously with that key as an option.

Removes the binding of value to key if it exists, otherwise this operation doesn't have any effect.

If this was the last value assigned to the specified key, the set assigned to that key will be removed as well.

Result collection consisting of all elements appended so far.

Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.

Note that expression pf.runWith(action)(x) is equivalent to

if(pf isDefinedAt x) { action(pf(x)); true } else false

except that runWith is implemented via applyOrElse and thus potentially more efficient. Using runWith avoids double evaluation of pattern matchers and guards for partial function literals.

Computes a prefix scan of the elements of the collection.

Note: The neutral element z may be applied more than once.

Produces a multimap containing cumulative results of applying the operator going left to right, including the initial value.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

Note: will not terminate for infinite-sized collections.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Example:

List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)

The size of this multimap.

Note: will not terminate for infinite-sized collections.

Compares the size of this multimap to the size of another Iterable.

Compares the size of this multimap to a test value.

Gives a hint that the result of this builder is expected to have the same size as the given collection, plus some delta.

This method provides a hint only if the collection has a known size, as specified by the following pseudocode:

if (coll.knownSize != -1)
  if (coll.knownSize + delta <= 0) sizeHint(0)
  else sizeHint(coll.knownSize + delta)

If the delta is negative and the result size is known to be negative, then the size hint is issued at zero.

Some builder classes will optimize their representation based on the hint. However, builder implementations are required to work correctly even if the hint is wrong, i.e., if a different number of elements is added.

Gives a hint how many elements are expected to be added in total by the time result is called.

Some builder classes will optimize their representation based on the hint. However, builder implementations are required to work correctly even if the hint is wrong, e.g., a different number of elements is added, or the hint is out of range.

The default implementation simply ignores the hint.

Gives a hint how many elements are expected to be added when the next result is called, together with an upper bound given by the size of some other collection. Some builder classes will optimize their representation based on the hint. However, builder implementations are still required to work correctly even if the hint is wrong, i.e. a different number of elements is added.

Returns a value class containing operations for comparing the size of this multimap to a test value.

These operations are implemented in terms of sizeCompare(Int), and allow the following more readable usages:

this.sizeIs < size     // this.sizeCompare(size) < 0
this.sizeIs <= size    // this.sizeCompare(size) <= 0
this.sizeIs == size    // this.sizeCompare(size) == 0
this.sizeIs != size    // this.sizeCompare(size) != 0
this.sizeIs >= size    // this.sizeCompare(size) >= 0
this.sizeIs > size     // this.sizeCompare(size) > 0

Selects an interval of elements. The returned multimap is made up of all elements x which satisfy the invariant:

from <= indexOf(x) < until

Note: might return different results for different runs, unless the underlying collection type is ordered.

Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped).

The returned iterator will be empty when called on an empty collection. The last element the iterator produces may be smaller than the window size when the original collection isn't exhausted by the window before it and its last element isn't skipped by the step before it.

Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped).

An empty collection returns an empty iterator, and a non-empty collection containing fewer elements than the window size returns an iterator that will produce the original collection as its only element.

Splits this multimap into a prefix/suffix pair according to a predicate.

Note: c span p is equivalent to (but possibly more efficient than) (c takeWhile p, c dropWhile p), provided the evaluation of the predicate p does not cause any side-effects.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Splits this multimap into a prefix/suffix pair at a given position.

Note: c splitAt n is equivalent to (but possibly more efficient than) (c take n, c drop n).

Note: might return different results for different runs, unless the underlying collection type is ordered.

Returns a scala.collection.Stepper for the elements of this collection.

The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.

The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.

• For collections of Int, Short, Byte or Char, an scala.collection.IntStepper is returned
• For collections of Double or Float, a scala.collection.DoubleStepper is returned
• For collections of Long a scala.collection.LongStepper is returned
• For any other element type, an scala.collection.AnyStepper is returned

Note that this method is overridden in subclasses and the return type is refined to S with EfficientSplit, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.

Removes all elements produced by an iterator from this multimap.

Sums the elements of this collection.

The default implementation uses reduce for a known non-empty collection, foldLeft otherwise.

Note: will not terminate for infinite-sized collections.

Executes the code in body with an exclusive lock on this.

The rest of the collection without its first element.

Iterates over the tails of this multimap. The first value will be this multimap and the final one will be an empty multimap, with the intervening values the results of successive applications of tail.

Selects the first n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Selects the last n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Takes longest prefix of elements that satisfy a predicate.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Applies a side-effecting function to each element in this collection. Strict collections will apply f to their elements immediately, while lazy collections like Views and LazyLists will only apply f on each element if and when that element is evaluated, and each time that element is evaluated.

Given a collection factory factory, converts this multimap to the appropriate representation for the current element type A. Example uses:

xs.to(List)
xs.to(ArrayBuffer)
xs.to(BitSet) // for xs: Iterable[Int]

Converts this multimap to an Array.

Implementation note: DO NOT call Array.from from this method.

Converts this multimap to a Buffer.

Converts this multimap to an IndexedSeq.