Alias for concat

The class name of this collection. To be used for converting to string. Collections generally print like this:

<className>(elem_1, ..., elem_n)

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

Finds the first element of the view 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.

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

Copy all elements of this collection to array xs, starting at start.

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

The rest of the collection without its n first elements. For linear, immutable collections this should avoid making a copy.

The rest of the collection without its n last elements. For linear, immutable collections this should avoid making a copy.

Drops longest prefix of elements that satisfy a predicate.

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

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

Finds the first element of the view 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.

Converts this view of traversable collections into a view formed by the elements of these traversable collections.

The resulting collection's type will be guided by the type of view. 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 a binary operator to a start value and all elements of this view, going left to right.

Note: will not terminate for infinite-sized collections.

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

Applies a binary operator to all elements of this view and a start value, going right to left.

Note: will not terminate for infinite-sized collections.

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

Partitions this view into a map of views according to some discriminator function.

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

Partitions this view into a map of views 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)

Partitions this view into a map according to a discriminator function key. All the values that have the same discriminator are then transformed by the value 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)(_ + _)

Partitions elements in fixed size views.

Selects the first element of this view.

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.

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

Tests whether the view is empty.

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

Iterator can be used only once

The number of elements in this collection, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.

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.

Zips that iterable collection with an existing LazyZip3. The elements in each collection are not consumed until a strict operation is invoked on the returned LazyZip4 decorator.

Finds the largest element.

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

Finds the smallest element.

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

Displays all elements of this view in a string.

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

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

Tests whether the view is not empty.

A pair of, first, all elements that satisfy prediacte p and, second, all elements that do not. Interesting because it splits a collection in two.

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

Multiplies up the elements of this collection.

Reduces the elements of this view using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Applies a binary operator to all elements of this view, going left to right.

Note: will not terminate for infinite-sized collections.

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

Optionally applies a binary operator to all elements of this view, going left to right.

Note: will not terminate for infinite-sized collections.

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

Reduces the elements of this view, if any, using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Applies a binary operator to all elements of this view, going right to left.

Note: will not terminate for infinite-sized collections.

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

Optionally applies a binary operator to all elements of this view, going right to left.

Note: will not terminate for infinite-sized collections.

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

Computes a prefix scan of the elements of the collection.

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

Produces a collection containing cumulative results of applying the operator going left to right.

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.

Example:

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

The size of this view.

Note: will not terminate for infinite-sized collections.

Selects an interval of elements. The returned collection 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.)

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

Splits this view 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 view into two 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.

Sums up the elements of this collection.

The rest of the collection without its first element.

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

A collection containing the first n elements of this collection.

A collection containing the last n elements of this collection.

Takes longest prefix of elements that satisfy a predicate.

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

Given a collection factory factory, convert this collection 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]

Convert collection to array.

Transposes this view of iterable collections into a view of views.

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

val xs = List(
           Set(1, 2, 3),
           Set(4, 5, 6)).transpose
// xs == List(
//         List(1, 4),
//         List(2, 5),
//         List(3, 6))

val ys = Vector(
           List(1, 2, 3),
           List(4, 5, 6)).transpose
// ys == Vector(
//         Vector(1, 4),
//         Vector(2, 5),
//         Vector(3, 6))

Converts this view of pairs into two collections of the first and second half of each pair.

val xs = `View`(
           (1, "one"),
           (2, "two"),
           (3, "three")).unzip
// xs == (`View`(1, 2, 3),
//        `View`(one, two, three))

A view over the elements of this collection.

Creates a non-strict filter of this view.

Note: the difference between c filter p and c withFilter p is that the former creates a new collection, whereas the latter only restricts the domain of subsequent map, flatMap, foreach, and withFilter operations.

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

Returns a view formed from this view and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.

Returns a view formed from this view and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

Zips this view with its indices.

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

Note: may not terminate for infinite-sized collections.

Selects all elements of this view which satisfy a predicate.

Builds a new collection by applying a function to all elements of this view 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 view. 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 => 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)

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

Note: may not terminate for infinite-sized collections.

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

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