class Collect[+A, B] extends AbstractView[B]
A view that collects elements of the underlying collection.
- Annotations
- @SerialVersionUID()
- Source
- View.scala
- Alphabetic
- By Inheritance
- Collect
- AbstractView
- View
- Serializable
- AbstractIterable
- Iterable
- IterableFactoryDefaults
- IterableOps
- IterableOnceOps
- IterableOnce
- AnyRef
- Any
- by iterableOnceExtensionMethods
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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- Public
- Protected
Instance Constructors
- new Collect(underlying: SomeIterableOps[A], pf: PartialFunction[A, B])
Value Members
- final def ++[B >: B](suffix: IterableOnce[B]): View[B]
Alias for
concat
Alias for
concat
- Definition Classes
- IterableOps
- Annotations
- @inline()
- final def addString(b: mutable.StringBuilder): b.type
Appends all elements of this view to a string builder.
Appends all elements of this view to a string builder. The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this view 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
- b
the string builder to which elements are appended.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- final def addString(b: mutable.StringBuilder, sep: String): b.type
Appends all elements of this view to a string builder using a separator string.
Appends all elements of this view 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 view, separated by the stringsep
.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
- b
the string builder to which elements are appended.
- sep
the separator string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- def addString(b: mutable.StringBuilder, start: String, sep: String, end: String): b.type
Appends all elements of this view to a string builder using start, end, and separator strings.
Appends all elements of this view to a string builder using start, end, and separator strings. The written text begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this view are separated by the stringsep
.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)
- b
the string builder to which elements are appended.
- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
the string builder
b
to which elements were appended.
- Definition Classes
- IterableOnceOps
- def collect[B](pf: PartialFunction[B, B]): View[B]
Builds a new view by applying a partial function to all elements of this view on which the function is defined.
Builds a new view by applying a partial function to all elements of this view on which the function is defined.
- B
the element type of the returned view.
- pf
the partial function which filters and maps the view.
- returns
a new view resulting from applying the given partial function
pf
to each element on which it is defined and collecting the results. The order of the elements is preserved.
- Definition Classes
- IterableOps → IterableOnceOps
- def collectFirst[B](pf: PartialFunction[B, B]): Option[B]
Finds the first element of the view for which the given partial function is defined, and applies the partial function to it.
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.
- pf
the partial function
- returns
an option value containing pf applied to the first value for which it is defined, or
None
if none exists.
- Definition Classes
- IterableOnceOps
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Example: - def concat[B >: B](suffix: IterableOnce[B]): View[B]
Returns a new view containing the elements from the left hand operand followed by the elements from the right hand operand.
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.
- B
the element type of the returned collection.
- suffix
the iterable to append.
- returns
a new view which contains all elements of this view followed by all elements of
suffix
.
- Definition Classes
- IterableOps
- def copyToArray[B >: B](xs: Array[B], start: Int, len: Int): Int
Copy elements to an array, returning the number of elements written.
Copy elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with at mostlen
elements of this view.Copying will stop once either all the elements of this view have been copied, or the end of the array is reached, or
len
elements have been copied.- B
the type of the elements of the array.
- xs
the array to fill.
- start
the starting index of xs.
- len
the maximal number of elements to copy.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def copyToArray[B >: B](xs: Array[B], start: Int): Int
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with values of this view.Copying will stop once either all the elements of this view have been copied, or the end of the array is reached.
- B
the type of the elements of the array.
- xs
the array to fill.
- start
the starting index of xs.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def copyToArray[B >: B](xs: Array[B]): Int
Copies elements to an array, returning the number of elements written.
Copies elements to an array, returning the number of elements written.
Fills the given array
xs
starting at indexstart
with values of this view.Copying will stop once either all the elements of this view have been copied, or the end of the array is reached.
- B
the type of the elements of the array.
- xs
the array to fill.
- returns
the number of elements written to the array
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- Note
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
- def corresponds[B](that: IterableOnce[B])(p: (B, B) => Boolean): Boolean
Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.
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.
- B
the type of the elements of
that
- that
the other collection
- p
the test predicate, which relates elements from both collections
- returns
true
if both collections have the same length andp(x, y)
istrue
for all corresponding elementsx
of this iterator andy
ofthat
, otherwisefalse
- Definition Classes
- IterableOnceOps
- def count(p: (B) => Boolean): Int
Counts the number of elements in the view which satisfy a predicate.
Counts the number of elements in the view which satisfy a predicate.
Note: will not terminate for infinite-sized collections.
- p
the predicate used to test elements.
- returns
the number of elements satisfying the predicate
p
.
- Definition Classes
- IterableOnceOps
- def drop(n: Int): View[B]
Selects all elements except the first
n
ones.Selects all elements except the first
n
ones.Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the number of elements to drop from this view.
- returns
a view consisting of all elements of this view except the first
n
ones, or else the empty view, if this view has less thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- IterableOps → IterableOnceOps
- def dropRight(n: Int): View[B]
Selects all elements except last n ones.
Selects all elements except last n ones.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the number of elements to drop from this view.
- returns
a view consisting of all elements of this view except the last
n
ones, or else the empty view, if this view has less thann
elements. Ifn
is negative, don't drop any elements.
- Definition Classes
- IterableOps
- def dropWhile(p: (B) => Boolean): View[B]
Selects all elements except the longest prefix that satisfies a predicate.
Selects all elements except the longest prefix that satisfies a predicate.
The matching prefix starts with the first element of this view, 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 view.
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.
- p
The predicate used to test elements.
- returns
the longest suffix of this view whose first element does not satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- def empty: View[B]
The empty iterable of the same type as this iterable.
The empty iterable of the same type as this iterable.
- returns
an empty iterable of type
C
.
- Definition Classes
- View → IterableFactoryDefaults → IterableOps
- def exists(p: (B) => Boolean): Boolean
Tests whether a predicate holds for at least one element of this view.
Tests whether a predicate holds for at least one element of this view.
Note: may not terminate for infinite-sized collections.
- p
the predicate used to test elements.
- returns
true
if the given predicatep
is satisfied by at least one element of this view, otherwisefalse
- Definition Classes
- IterableOnceOps
- def filter(pred: (B) => Boolean): View[B]
Selects all elements of this view which satisfy a predicate.
Selects all elements of this view which satisfy a predicate.
- returns
a new view consisting of all elements of this view that satisfy the given predicate
p
. The order of the elements is preserved.
- Definition Classes
- IterableOps → IterableOnceOps
- def filterNot(pred: (B) => Boolean): View[B]
Selects all elements of this view which do not satisfy a predicate.
Selects all elements of this view which do not satisfy a predicate.
- pred
the predicate used to test elements.
- returns
a new view consisting of all elements of this view that do not satisfy the given predicate
pred
. Their order may not be preserved.
- Definition Classes
- IterableOps → IterableOnceOps
- def find(p: (B) => Boolean): Option[B]
Finds the first element of the view satisfying a predicate, if any.
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.
- p
the predicate used to test elements.
- returns
an option value containing the first element in the view that satisfies
p
, orNone
if none exists.
- Definition Classes
- IterableOnceOps
- def flatMap[B](f: (B) => IterableOnce[B]): View[B]
Builds a new view by applying a function to all elements of this view and using the elements of the resulting collections.
Builds a new view 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: 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)
- B
the element type of the returned collection.
- f
the function to apply to each element.
- returns
a new view resulting from applying the given collection-valued function
f
to each element of this view and concatenating the results.
- Definition Classes
- IterableOps → IterableOnceOps
- def flatten[B](implicit asIterable: (B) => IterableOnce[B]): View[B]
Converts this view of iterable collections into a view formed by the elements of these iterable collections.
Converts this view of iterable collections into a view formed by the elements of these iterable 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)
- B
the type of the elements of each iterable collection.
- asIterable
an implicit conversion which asserts that the element type of this view is an
Iterable
.- returns
a new view resulting from concatenating all element views.
- Definition Classes
- IterableOps → IterableOnceOps
- def fold[A1 >: B](z: A1)(op: (A1, A1) => A1): A1
Applies the given binary operator
op
to the given initial valuez
and all elements of this view.Applies the given binary operator
op
to the given initial valuez
and all elements of this view.For each application of the operator, each operand is either an element of this view, 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
forList
concatenation or1
for multiplication.The default implementation in
IterableOnce
is equivalent tofoldLeft
but may be overridden for more efficient traversal orders.Note: will not terminate for infinite-sized collections.
- A1
The type parameter for the binary operator, a supertype of
A
.- z
An initial value; may be used an arbitrary number of times in the computation of the result; must be a neutral value for
op
for the result to always be the same across runs.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of applying
op
between all the elements andz
, orz
if this view is empty.
- Definition Classes
- IterableOnceOps
- def foldLeft[B](z: B)(op: (B, B) => B): B
Applies the given binary operator
op
to the given initial valuez
and all elements of this view, going left to right.Applies the given binary operator
op
to the given initial valuez
and all elements of this view, going left to right. Returns the initial value if this view is empty."Going left to right" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this view, the result isop( 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 view 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.
- B
The result type of the binary operator.
- z
An initial value.
- op
A binary operator.
- returns
The result of applying
op
toz
and all elements of this view, going left to right. Returnsz
if this view is empty.
- Definition Classes
- IterableOnceOps
- def foldRight[B](z: B)(op: (B, B) => B): B
Applies the given binary operator
op
to all elements of this view and the given initial valuez
, going right to left.Applies the given binary operator
op
to all elements of this view and the given initial valuez
, going right to left. Returns the initial value if this view is empty."Going right to left" only makes sense if this collection is ordered: then if
x1
,x2
, ...,xn
are the elements of this view, the result isop(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 view 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.
- B
The result type of the binary operator.
- z
An initial value.
- op
A binary operator.
- returns
The result of applying
op
to all elements of this view andz
, going right to left. Returnsz
if this view is empty.
- Definition Classes
- IterableOnceOps
- def forall(p: (B) => Boolean): Boolean
Tests whether a predicate holds for all elements of this view.
Tests whether a predicate holds for all elements of this view.
Note: may not terminate for infinite-sized collections.
- p
the predicate used to test elements.
- returns
true
if this view is empty or the given predicatep
holds for all elements of this view, otherwisefalse
.
- Definition Classes
- IterableOnceOps
- def foreach[U](f: (B) => U): Unit
Applies
f
to each element for its side effects.Applies
f
to each element for its side effects. Note:U
parameter needed to help scalac's type inference.- Definition Classes
- IterableOnceOps
- def groupBy[K](f: (B) => K): immutable.Map[K, View[B]]
Partitions this view into a map of views according to some discriminator function.
Partitions this view into a map of views according to some discriminator function.
Note: Even when applied to a view or a lazy collection it will always force the elements.
- K
the type of keys returned by the discriminator function.
- f
the discriminator function.
- returns
A map from keys to views such that the following invariant holds:
(xs groupBy f)(k) = xs filter (x => f(x) == k)
That is, every key
k
is bound to a view of those elementsx
for whichf(x)
equalsk
.
- Definition Classes
- IterableOps
- def groupMap[K, B](key: (B) => K)(f: (B) => B): immutable.Map[K, View[B]]
Partitions this view into a map of views according to a discriminator function
key
.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 typeB
using thevalue
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.
- K
the type of keys returned by the discriminator function
- B
the type of values returned by the transformation function
- key
the discriminator function
- f
the element transformation function
- Definition Classes
- IterableOps
- def groupMapReduce[K, B](key: (B) => K)(f: (B) => B)(reduce: (B, B) => B): immutable.Map[K, B]
Partitions this view into a map according to a discriminator function
key
.Partitions this view into a map according to a discriminator function
key
. All the values that have the same discriminator are then transformed by thef
function and then reduced into a single value with thereduce
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.
- Definition Classes
- IterableOps
- def grouped(size: Int): Iterator[View[B]]
Partitions elements in fixed size views.
Partitions elements in fixed size views.
- size
the number of elements per group
- returns
An iterator producing views of size
size
, except the last will be less than sizesize
if the elements don't divide evenly.
- Definition Classes
- IterableOps
- See also
scala.collection.Iterator, method
grouped
- def head: B
Selects the first element of this view.
Selects the first element of this view.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the first element of this view.
- Definition Classes
- IterableOps
- Exceptions thrown
NoSuchElementException
if the view is empty.
- def headOption: Option[B]
Optionally selects the first element.
Optionally selects the first element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the first element of this view if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
- def init: View[B]
The initial part of the collection without its last element.
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.
- Definition Classes
- IterableOps
- def inits: Iterator[View[B]]
Iterates over the inits of this view.
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
.Note: Even when applied to a view or a lazy collection it will always force the elements.
- returns
an iterator over all the inits of this view
- Definition Classes
- IterableOps
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
Example: - def isEmpty: Boolean
Tests whether the view is empty.
Tests whether the view 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.- returns
true
if the view contains no elements,false
otherwise.
- Definition Classes
- IterableOnceOps
- def isTraversableAgain: Boolean
Tests whether this view can be repeatedly traversed.
Tests whether this view can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.
- returns
true
if it is repeatedly traversable,false
otherwise.
- Definition Classes
- IterableOps → IterableOnceOps
- def iterableFactory: IterableFactory[View]
The companion object of this view, providing various factory methods.
The companion object of this view, providing various factory methods.
- Definition Classes
- View → Iterable → IterableOps
- Note
When implementing a custom collection type and refining
CC
to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).
- def iterator: Iterator[B]
An scala.collection.Iterator over the elements of this view.
An scala.collection.Iterator over the elements of this view.
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.- Definition Classes
- Collect → IterableOnce
- def knownSize: Int
The number of elements in this view, if it can be cheaply computed, -1 otherwise.
The number of elements in this view, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.
- Definition Classes
- IterableOnce
- def last: B
Selects the last element.
Selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
The last element of this view.
- Definition Classes
- IterableOps
- Exceptions thrown
NoSuchElementException
If the view is empty.
- def lastOption: Option[B]
Optionally selects the last element.
Optionally selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- returns
the last element of this view$ if it is nonempty,
None
if it is empty.
- Definition Classes
- IterableOps
- def lazyZip[B](that: Iterable[B]): LazyZip2[B, B, Collect.this.type]
Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
decorator.Analogous to
zip
except that the elements in each collection are not consumed until a strict operation is invoked on the returnedLazyZip2
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)
- B
the type of the second element in each eventual pair
- that
the iterable providing the second element of each eventual pair
- returns
a decorator
LazyZip2
that allows strict operations to be performed on the lazily evaluated pairs or chained calls tolazyZip
. Implicit conversion toIterable[(A, B)]
is also supported.
- Definition Classes
- Iterable
- def map[B](f: (B) => B): View[B]
Builds a new view by applying a function to all elements of this view.
Builds a new view by applying a function to all elements of this view.
- B
the element type of the returned view.
- f
the function to apply to each element.
- returns
a new view resulting from applying the given function
f
to each element of this view and collecting the results.
- Definition Classes
- IterableOps → IterableOnceOps
- def max[B >: B](implicit ord: math.Ordering[B]): B
Finds the largest element.
Finds the largest element.
Note: will not terminate for infinite-sized collections.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
the largest element of this view with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def maxBy[B](f: (B) => B)(implicit ord: math.Ordering[B]): B
Finds the first element which yields the largest value measured by function
f
.Finds the first element which yields the largest value measured by function
f
.Note: will not terminate for infinite-sized collections.
- B
The result type of the function
f
.- f
The measuring function.
- returns
the first element of this view with the largest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def maxByOption[B](f: (B) => B)(implicit ord: math.Ordering[B]): Option[B]
Finds the first element which yields the largest value measured by function
f
.Finds the first element which yields the largest value measured by function
f
.Note: will not terminate for infinite-sized collections.
- B
The result type of the function
f
.- f
The measuring function.
- returns
an option value containing the first element of this view with the largest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- def maxOption[B >: B](implicit ord: math.Ordering[B]): Option[B]
Finds the largest element.
Finds the largest element.
Note: will not terminate for infinite-sized collections.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
an option value containing the largest element of this view with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- def min[B >: B](implicit ord: math.Ordering[B]): B
Finds the smallest element.
Finds the smallest element.
Note: will not terminate for infinite-sized collections.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
the smallest element of this view with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def minBy[B](f: (B) => B)(implicit ord: math.Ordering[B]): B
Finds the first element which yields the smallest value measured by function
f
.Finds the first element which yields the smallest value measured by function
f
.Note: will not terminate for infinite-sized collections.
- B
The result type of the function
f
.- f
The measuring function.
- returns
the first element of this view with the smallest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def minByOption[B](f: (B) => B)(implicit ord: math.Ordering[B]): Option[B]
Finds the first element which yields the smallest value measured by function
f
.Finds the first element which yields the smallest value measured by function
f
.Note: will not terminate for infinite-sized collections.
- B
The result type of the function
f
.- f
The measuring function.
- returns
an option value containing the first element of this view with the smallest value measured by function
f
with respect to the orderingcmp
.
- Definition Classes
- IterableOnceOps
- def minOption[B >: B](implicit ord: math.Ordering[B]): Option[B]
Finds the smallest element.
Finds the smallest element.
Note: will not terminate for infinite-sized collections.
- B
The type over which the ordering is defined.
- ord
An ordering to be used for comparing elements.
- returns
an option value containing the smallest element of this view with respect to the ordering
ord
.
- Definition Classes
- IterableOnceOps
- final def mkString: String
Displays all elements of this view in a string.
Displays all elements of this view in a string.
Delegates to addString, which can be overridden.
- returns
a string representation of this view. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this view follow each other without any separator string.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- final def mkString(sep: String): String
Displays all elements of this view in a string using a separator string.
Displays all elements of this view in a string using a separator string.
Delegates to addString, which can be overridden.
- sep
the separator string.
- returns
a string representation of this view. In the resulting string the string representations (w.r.t. the method
toString
) of all elements of this view are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
List(1, 2, 3).mkString("|") = "1|2|3"
Example: - final def mkString(start: String, sep: String, end: String): String
Displays all elements of this view in a string using start, end, and separator strings.
Displays all elements of this view in a string using start, end, and separator strings.
Delegates to addString, which can be overridden.
- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
a string representation of this view. The resulting string begins with the string
start
and ends with the stringend
. Inside, the string representations (w.r.t. the methodtoString
) of all elements of this view are separated by the stringsep
.
- Definition Classes
- IterableOnceOps
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Example: - def nonEmpty: Boolean
Tests whether the view is not empty.
Tests whether the view is not empty.
- returns
true
if the view contains at least one element,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecatedOverriding()
- def partition(p: (B) => Boolean): (View[B], View[B])
A pair of, first, all elements that satisfy predicate
p
and, second, all elements that do not.A pair of, first, all elements that satisfy predicate
p
and, second, all elements that do not.The two view 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
inStrictOptimizedIterableOps
, which requires only a single traversal.- Definition Classes
- IterableOps
- def partitionMap[A1, A2](f: (B) => Either[A1, A2]): (View[A1], View[A2])
Applies a function
f
to each element of the view and returns a pair of views: the first one made of those values returned byf
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.Applies a function
f
to each element of the view and returns a pair of views: the first one made of those values returned byf
that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.Example:
val xs = `View`(1, "one", 2, "two", 3, "three") partitionMap { case i: Int => Left(i) case s: String => Right(s) } // xs == (`View`(1, 2, 3), // `View`(one, two, three))
- A1
the element type of the first resulting collection
- A2
the element type of the second resulting collection
- f
the 'split function' mapping the elements of this view to an scala.util.Either
- returns
a pair of views: 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.
- Definition Classes
- IterableOps
- def product[B >: B](implicit num: math.Numeric[B]): B
Multiplies together the elements of this collection.
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.
- B
the result type of the
*
operator.- num
an implicit parameter defining a set of numeric operations which includes the
*
operator to be used in forming the product.- returns
the product of all elements of this view with respect to the
*
operator innum
.
- Definition Classes
- IterableOnceOps
- def reduce[B >: B](op: (B, B) => B): B
Applies the given binary operator
op
to all elements of this view.Applies the given binary operator
op
to all elements of this view.For each application of the operator, each operand is either an element of this view 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.
- B
The type parameter for the binary operator, a supertype of
A
.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of applying
op
between all the elements if the view is nonempty.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def reduceLeft[B >: B](op: (B, B) => B): B
Applies the given binary operator
op
to all elements of this view, going left to right.Applies the given binary operator
op
to all elements of this view, 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 view, the result isop( 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 view 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.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of applying
op
to all elements of this view, going left to right.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def reduceLeftOption[B >: B](op: (B, B) => B): Option[B]
If this view is nonempty, reduces it with the given binary operator
op
, going left to right.If this view 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 view 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.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of reducing this view with
op
going left to right if the view is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def reduceOption[B >: B](op: (B, B) => B): Option[B]
If this view is nonempty, reduces it with the given binary operator
op
.If this view 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 view 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.
- B
A type parameter for the binary operator, a supertype of
A
.- op
A binary operator; must be associative for the result to always be the same across runs.
- returns
The result of reducing this view with
op
if the view is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def reduceRight[B >: B](op: (B, B) => B): B
Applies the given binary operator
op
to all elements of this view, going right to left.Applies the given binary operator
op
to all elements of this view, 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 view, the result isop(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 view 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.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of applying
op
to all elements of this view, going right to left.
- Definition Classes
- IterableOnceOps
- Exceptions thrown
UnsupportedOperationException
if this view is empty.
- def reduceRightOption[B >: B](op: (B, B) => B): Option[B]
If this view is nonempty, reduces it with the given binary operator
op
, going right to left.If this view 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 view 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.
- B
The result type of the binary operator, a supertype of
A
.- op
A binary operator.
- returns
The result of reducing this view with
op
going right to left if the view is nonempty, inside aSome
, andNone
otherwise.
- Definition Classes
- IterableOnceOps
- def scan[B >: B](z: B)(op: (B, B) => B): View[B]
Computes a prefix scan of the elements of the collection.
Computes a prefix scan of the elements of the collection.
Note: The neutral element
z
may be applied more than once.- B
element type of the resulting collection
- z
neutral element for the operator
op
- op
the associative operator for the scan
- returns
a new view containing the prefix scan of the elements in this view
- Definition Classes
- IterableOps
- def scanLeft[B](z: B)(op: (B, B) => B): View[B]
Produces a view containing cumulative results of applying the operator going left to right, including the initial value.
Produces a view 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.
- B
the type of the elements in the resulting collection
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- IterableOps → IterableOnceOps
- def scanRight[B](z: B)(op: (B, B) => B): View[B]
Produces a collection containing cumulative results of applying the operator going right to left.
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)
- B
the type of the elements in the resulting collection
- z
the initial value
- op
the binary operator applied to the intermediate result and the element
- returns
collection with intermediate results
- Definition Classes
- IterableOps
- def size: Int
The size of this view.
The size of this view.
Note: will not terminate for infinite-sized collections.
- returns
the number of elements in this view.
- Definition Classes
- IterableOnceOps
- def sizeCompare(that: Iterable[_]): Int
Compares the size of this view to the size of another
Iterable
.Compares the size of this view to the size of another
Iterable
.- that
the
Iterable
whose size is compared with this view's size.- returns
A value
x
wherex < 0 if this.size < that.size x == 0 if this.size == that.size x > 0 if this.size > that.size
The method as implemented here does not call
size
directly; its running time isO(this.size min that.size)
instead ofO(this.size + that.size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- IterableOps
- def sizeCompare(otherSize: Int): Int
Compares the size of this view to a test value.
Compares the size of this view to a test value.
- otherSize
the test value that gets compared with the size.
- returns
A value
x
wherex < 0 if this.size < otherSize x == 0 if this.size == otherSize x > 0 if this.size > otherSize
The method as implemented here does not call
size
directly; its running time isO(size min otherSize)
instead ofO(size)
. The method should be overridden if computingsize
is cheap andknownSize
returns-1
.
- Definition Classes
- IterableOps
- See also
- final def sizeIs: SizeCompareOps
Returns a value class containing operations for comparing the size of this view to a test value.
Returns a value class containing operations for comparing the size of this view 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
- Definition Classes
- IterableOps
- Annotations
- @inline()
- def slice(from: Int, until: Int): View[B]
Selects an interval of elements.
Selects an interval of elements. The returned view 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.
- from
the lowest index to include from this view.
- until
the lowest index to EXCLUDE from this view.
- returns
a view containing the elements greater than or equal to index
from
extending up to (but not including) indexuntil
of this view.
- Definition Classes
- IterableOps → IterableOnceOps
- def sliding(size: Int, step: Int): Iterator[View[B]]
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 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.
- size
the number of elements per group
- step
the distance between the first elements of successive groups
- returns
An iterator producing views of size
size
, except the last element (which may be the only element) will be smaller if there are fewer thansize
elements remaining to be grouped.
- Definition Classes
- IterableOps
List(1, 2, 3, 4, 5).sliding(2, 2) = Iterator(List(1, 2), List(3, 4), List(5))
, List(1, 2, 3, 4, 5, 6).sliding(2, 3) = Iterator(List(1, 2), List(4, 5))
- See also
scala.collection.Iterator, method
sliding
Examples: - def sliding(size: Int): Iterator[View[B]]
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
).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.
- size
the number of elements per group
- returns
An iterator producing views of size
size
, except for a non-empty collection with less thansize
elements, which returns an iterator that produces the source collection itself as its only element.
- Definition Classes
- IterableOps
List().sliding(2) = empty iterator
, List(1).sliding(2) = Iterator(List(1))
, List(1, 2).sliding(2) = Iterator(List(1, 2))
, List(1, 2, 3).sliding(2) = Iterator(List(1, 2), List(2, 3))
- See also
scala.collection.Iterator, method
sliding
Examples: - def span(p: (B) => Boolean): (View[B], View[B])
Splits this view into a prefix/suffix pair according to a predicate.
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 predicatep
does not cause any side-effects.Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the test predicate
- returns
a pair consisting of the longest prefix of this view whose elements all satisfy
p
, and the rest of this view.
- Definition Classes
- IterableOps → IterableOnceOps
- def splitAt(n: Int): (View[B], View[B])
Splits this view into a prefix/suffix pair at a given position.
Splits this view 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.
- n
the position at which to split.
- returns
a pair of views consisting of the first
n
elements of this view, and the other elements.
- Definition Classes
- IterableOps → IterableOnceOps
- def stepper[S <: Stepper[_]](implicit shape: StepperShape[B, S]): S
Returns a scala.collection.Stepper for the elements of this collection.
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
orChar
, an scala.collection.IntStepper is returned - For collections of
Double
orFloat
, 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.- Definition Classes
- IterableOnce
- For collections of
- def sum[B >: B](implicit num: math.Numeric[B]): B
Sums the elements of this collection.
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.
- B
the result type of the
+
operator.- num
an implicit parameter defining a set of numeric operations which includes the
+
operator to be used in forming the sum.- returns
the sum of all elements of this view with respect to the
+
operator innum
.
- Definition Classes
- IterableOnceOps
- def tail: View[B]
The rest of the collection without its first element.
The rest of the collection without its first element.
- Definition Classes
- IterableOps
- def tails: Iterator[View[B]]
Iterates over the tails of this view.
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
.- returns
an iterator over all the tails of this view
- Definition Classes
- IterableOps
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Example: - def take(n: Int): View[B]
Selects the first
n
elements.Selects the first
n
elements.Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the number of elements to take from this view.
- returns
a view consisting only of the first
n
elements of this view, or else the whole view, if it has less thann
elements. Ifn
is negative, returns an empty view.
- Definition Classes
- IterableOps → IterableOnceOps
- def takeRight(n: Int): View[B]
Selects the last n elements.
Selects the last n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- n
the number of elements to take from this view.
- returns
a view consisting only of the last
n
elements of this view, or else the whole view, if it has less thann
elements. Ifn
is negative, returns an empty view.
- Definition Classes
- IterableOps
- def takeWhile(p: (B) => Boolean): View[B]
Takes longest prefix of elements that satisfy a predicate.
Takes longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
The predicate used to test elements.
- returns
the longest prefix of this view whose elements all satisfy the predicate
p
.
- Definition Classes
- IterableOps → IterableOnceOps
- def tapEach[U](f: (B) => U): View[B]
Applies a side-effecting function to each element in this collection.
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 applyf
on each element if and when that element is evaluated, and each time that element is evaluated.- U
the return type of f
- f
a function to apply to each element in this view
- returns
The same logical collection as this
- Definition Classes
- IterableOps → IterableOnceOps
- def to[C1](factory: Factory[B, C1]): C1
Given a collection factory
factory
, converts this view to the appropriate representation for the current element typeA
.Given a collection factory
factory
, converts this view to the appropriate representation for the current element typeA
. Example uses:xs.to(List) xs.to(ArrayBuffer) xs.to(BitSet) // for xs: Iterable[Int]
- Definition Classes
- IterableOnceOps
- def toArray[B >: B](implicit arg0: ClassTag[B]): Array[B]
Converts this view to an
Array
.Converts this view to an
Array
.Implementation note: DO NOT call Array.from from this method.
- B
The type of elements of the result, a supertype of
A
.- returns
This view as an
Array[B]
.
- Definition Classes
- IterableOnceOps
- final def toBuffer[B >: B]: Buffer[B]
Converts this view to a
Buffer
.Converts this view to a
Buffer
.- B
The type of elements of the result, a supertype of
A
.- returns
This view as a
Buffer[B]
.
- Definition Classes
- IterableOnceOps
- Annotations
- @inline()
- def toIndexedSeq: immutable.IndexedSeq[B]
Converts this view to an
IndexedSeq
.Converts this view to an
IndexedSeq
.- returns
This view as an
IndexedSeq[A]
.
- Definition Classes
- IterableOnceOps
- def toList: immutable.List[B]
Converts this view to a
List
. - def toMap[K, V](implicit ev: <:<[B, (K, V)]): immutable.Map[K, V]
Converts this view to a
Map
, given an implicit coercion from the view's type to a key-value tuple.Converts this view to a
Map
, given an implicit coercion from the view's type to a key-value tuple.- K
The key type for the resulting map.
- V
The value type for the resulting map.
- ev
An implicit coercion from
A
to[K, V]
.- returns
This view as a
Map[K, V]
.
- Definition Classes
- IterableOnceOps
- def toSeq: immutable.Seq[B]
- returns
This view as a
Seq[A]
. This is equivalent toto(Seq)
but might be faster.
- Definition Classes
- IterableOnceOps
- def toSet[B >: B]: immutable.Set[B]
Converts this view to a
Set
.Converts this view to a
Set
.- B
The type of elements of the result, a supertype of
A
.- returns
This view as a
Set[B]
.
- Definition Classes
- IterableOnceOps
- def toString(): String
Converts this view to a string.
- def toVector: immutable.Vector[B]
Converts this view to a
Vector
. - def transpose[B](implicit asIterable: (B) => Iterable[B]): View[View[B]]
Transposes this view of iterable collections into a view of views.
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))
Note: Even when applied to a view or a lazy collection it will always force the elements.
- B
the type of the elements of each iterable collection.
- asIterable
an implicit conversion which asserts that the element type of this view is an
Iterable
.- returns
a two-dimensional view of views which has as nth row the nth column of this view.
- Definition Classes
- IterableOps
- Exceptions thrown
IllegalArgumentException
if all collections in this view are not of the same size.
- def unzip[A1, A2](implicit asPair: (B) => (A1, A2)): (View[A1], View[A2])
Converts this view of pairs into two collections of the first and second half of each pair.
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))
- A1
the type of the first half of the element pairs
- A2
the type of the second half of the element pairs
- asPair
an implicit conversion which asserts that the element type of this view is a pair.
- returns
a pair of views, containing the first, respectively second half of each element pair of this view.
- Definition Classes
- IterableOps
- def unzip3[A1, A2, A3](implicit asTriple: (B) => (A1, A2, A3)): (View[A1], View[A2], View[A3])
Converts this view of triples into three collections of the first, second, and third element of each triple.
Converts this view of triples into three collections of the first, second, and third element of each triple.
val xs = `View`( (1, "one", '1'), (2, "two", '2'), (3, "three", '3')).unzip3 // xs == (`View`(1, 2, 3), // `View`(one, two, three), // `View`(1, 2, 3))
- A1
the type of the first member of the element triples
- A2
the type of the second member of the element triples
- A3
the type of the third member of the element triples
- asTriple
an implicit conversion which asserts that the element type of this view is a triple.
- returns
a triple of views, containing the first, second, respectively third member of each element triple of this view.
- Definition Classes
- IterableOps
- def view: View[B]
A view over the elements of this collection.
A view over the elements of this collection.
- Definition Classes
- View → IterableOps
- def withFilter(p: (B) => Boolean): WithFilter[B, [_]View[_]]
Creates a non-strict filter of this view.
Creates a non-strict filter of this view.
Note: the difference between
c filter p
andc withFilter p
is that the former creates a new collection, whereas the latter only restricts the domain of subsequentmap
,flatMap
,foreach
, andwithFilter
operations.Note: might return different results for different runs, unless the underlying collection type is ordered.
- p
the predicate used to test elements.
- returns
an object of class
WithFilter
, which supportsmap
,flatMap
,foreach
, andwithFilter
operations. All these operations apply to those elements of this view which satisfy the predicatep
.
- Definition Classes
- IterableOps
- def zip[B](that: IterableOnce[B]): View[(B, B)]
Returns a view formed from this view and another iterable collection by combining corresponding elements in pairs.
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.
- B
the type of the second half of the returned pairs
- that
The iterable providing the second half of each result pair
- returns
a new view containing pairs consisting of corresponding elements of this view and
that
. The length of the returned collection is the minimum of the lengths of this view andthat
.
- Definition Classes
- IterableOps
- def zipAll[A1 >: B, B](that: Iterable[B], thisElem: A1, thatElem: B): View[(A1, B)]
Returns a view formed from this view and another iterable collection by combining corresponding elements in pairs.
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.
- that
the iterable providing the second half of each result pair
- thisElem
the element to be used to fill up the result if this view is shorter than
that
.- thatElem
the element to be used to fill up the result if
that
is shorter than this view.- returns
a new collection of type
That
containing pairs consisting of corresponding elements of this view andthat
. The length of the returned collection is the maximum of the lengths of this view andthat
. If this view is shorter thanthat
,thisElem
values are used to pad the result. Ifthat
is shorter than this view,thatElem
values are used to pad the result.
- Definition Classes
- IterableOps
- def zipWithIndex: View[(B, Int)]
Zips this view with its indices.
Zips this view with its indices.
- returns
A new view containing pairs consisting of all elements of this view paired with their index. Indices start at
0
.
- Definition Classes
- IterableOps → IterableOnceOps
List("a", "b", "c").zipWithIndex == List(("a", 0), ("b", 1), ("c", 2))
Example:
Deprecated Value Members
- def ++:[B >: B](that: IterableOnce[B]): View[B]
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use ++ instead of ++: for collections of type Iterable
- def /:[B](z: B)(op: (B, B) => B): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldLeft instead
- final def /:[B](z: B)(op: (B, B) => B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldLeft instead of /:
- def :\[B](z: B)(op: (B, B) => B): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
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- Definition Classes
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- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldRight instead
- final def :\[B](z: B)(op: (B, B) => B): B
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use foldRight instead of :\
- def aggregate[B](z: => B)(seqop: (B, B) => B, combop: (B, B) => B): B
Aggregates the results of applying an operator to subsequent elements.
Aggregates the results of applying an operator to subsequent elements.
Since this method degenerates to
foldLeft
for sequential (non-parallel) collections, where the combining operation is ignored, it is advisable to preferfoldLeft
for that case.For parallel collections, use the
aggregate
method specified byscala.collection.parallel.ParIterableLike
.- B
the result type, produced by
seqop
,combop
, and by this function as a final result.- z
the start value, a neutral element for
seqop
.- seqop
the binary operator used to accumulate the result.
- combop
an associative operator for combining sequential results, unused for sequential collections.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) For sequential collections, prefer
foldLeft(z)(seqop)
. For parallel collections, useParIterableLike#aggregate
.
- def collectFirst[B](f: PartialFunction[B, B]): Option[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.collectFirst(...) instead
- def companion: IterableFactory[[_]View[_]]
- Definition Classes
- IterableOps
- Annotations
- @deprecated @deprecatedOverriding() @inline()
- Deprecated
(Since version 2.13.0) Use iterableFactory instead
- def copyToBuffer(dest: Buffer[B]): Unit
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.copyToBuffer(...) instead
- final def copyToBuffer[B >: B](dest: Buffer[B]): Unit
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use
dest ++= coll
instead
- def count(f: (B) => Boolean): Int
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.count(...) instead
- def exists(f: (B) => Boolean): Boolean
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.exists(...) instead
- def filter(f: (B) => Boolean): Iterator[B]
- Implicit
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.filter(...) instead
- def find(p: (B) => Boolean): Option[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.find instead
- def flatMap[B](f: (B) => IterableOnce[B]): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.flatMap instead or consider requiring an Iterable
- def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.fold instead
- def foldLeft[B](z: B)(op: (B, B) => B): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldLeft instead
- def foldRight[B](z: B)(op: (B, B) => B): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foldRight instead
- def forall(f: (B) => Boolean): Boolean
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.forall(...) instead
- def force: IndexedSeq[B]
- Definition Classes
- View
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Views no longer know about their underlying collection type; .force always returns an IndexedSeq
- def foreach[U](f: (B) => U): Unit
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.foreach(...) instead
- def hasDefiniteSize: Boolean
Tests whether this view is known to have a finite size.
Tests whether this view is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as
Stream
, the predicate returnstrue
if all elements have been computed. It returnsfalse
if the stream is not yet evaluated to the end. Non-empty Iterators usually returnfalse
even if they were created from a collection with a known finite size.Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that
hasDefiniteSize
returnstrue
. However, checkinghasDefiniteSize
can provide an assurance that size is well-defined and non-termination is not a concern.- returns
true
if this collection is known to have finite size,false
otherwise.
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Check .knownSize instead of .hasDefiniteSize for more actionable information (see scaladoc for details)
- See also
method
knownSize
for a more useful alternative
- def isEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.isEmpty instead
- def map[B](f: (B) => B): IterableOnce[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.map instead or consider requiring an Iterable
- def max(implicit ord: math.Ordering[B]): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- This implicitly inherited member is shadowed by one or more members in this class.
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- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.max instead
- def maxBy[B](f: (B) => B)(implicit cmp: math.Ordering[B]): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.maxBy(...) instead
- def min(implicit ord: math.Ordering[B]): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.min instead
- def minBy[B](f: (B) => B)(implicit cmp: math.Ordering[B]): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.minBy(...) instead
- def mkString: String
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def mkString(sep: String): String
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def mkString(start: String, sep: String, end: String): String
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- Deprecated
(Since version 2.13.0) Use .iterator.mkString instead
- def nonEmpty: Boolean
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.nonEmpty instead
- def product(implicit num: math.Numeric[B]): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.product instead
- def reduce(f: (B, B) => B): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduce(...) instead
- def reduceLeft(f: (B, B) => B): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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- @deprecated
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(Since version 2.13.0) Use .iterator.reduceLeft(...) instead
- def reduceLeftOption(f: (B, B) => B): Option[B]
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- Deprecated
(Since version 2.13.0) Use .iterator.reduceLeftOption(...) instead
- def reduceOption(f: (B, B) => B): Option[B]
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- @deprecated
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(Since version 2.13.0) Use .iterator.reduceOption(...) instead
- def reduceRight(f: (B, B) => B): B
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(Since version 2.13.0) Use .iterator.reduceRight(...) instead
- def reduceRightOption(f: (B, B) => B): Option[B]
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- Definition Classes
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- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.reduceRightOption(...) instead
- final def repr: View[B]
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use coll instead of repr in a collection implementation, use the collection value itself from the outside
- def sameElements[B >: A](that: IterableOnce[B]): Boolean
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.sameElements instead
- def seq: Collect.this.type
- Definition Classes
- Iterable
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Iterable.seq always returns the iterable itself
- def size: Int
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).size
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.size instead
- def sum(implicit num: math.Numeric[B]): B
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).sum(num)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.sum instead
- def to[C1](factory: Factory[B, C1]): C1
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).to(factory)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(factory) instead
- def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toArray(arg0)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.toArray
- def toBuffer[B >: A]: Buffer[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toBuffer
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(ArrayBuffer) instead
- def toIndexedSeq: IndexedSeq[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toIndexedSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.toIndexedSeq instead
- final def toIterable: Iterable[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toIterable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Iterable) instead
- final def toIterable: Collect.this.type
- returns
This collection as an
Iterable[A]
. No new collection will be built ifthis
is already anIterable[A]
.
- Definition Classes
- Iterable → IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.7) toIterable is internal and will be made protected; its name is similar to
toList
ortoSeq
, but it doesn't copy non-immutable collections
- def toIterator: Iterator[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toIterator
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator instead
- final def toIterator: Iterator[B]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator instead of .toIterator
- def toList: immutable.List[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toList
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(List) instead
- def toMap[K, V](implicit ev: <:<[B, (K, V)]): immutable.Map[K, V]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toMap(ev)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.to(Map) instead
- def toSeq: immutable.Seq[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toSeq
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Seq) instead
- def toSet[B >: A]: immutable.Set[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toSet
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Set) instead
- def toStream: immutable.Stream[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toStream
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(LazyList) instead
- final def toStream: immutable.Stream[B]
- Definition Classes
- IterableOnceOps
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .to(LazyList) instead of .toStream
- final def toTraversable: Traversable[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toTraversable
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Iterable) instead
- final def toTraversable: Traversable[B]
Converts this view to an unspecified Iterable.
Converts this view to an unspecified Iterable. Will return the same collection if this instance is already Iterable.
- returns
An Iterable containing all elements of this view.
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) toTraversable is internal and will be made protected; its name is similar to
toList
ortoSeq
, but it doesn't copy non-immutable collections
- def toVector: immutable.Vector[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).toVector
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.13.0) Use .iterator.to(Vector) instead
- def view(from: Int, until: Int): View[B]
A view over a slice of the elements of this collection.
A view over a slice of the elements of this collection.
- Definition Classes
- IterableOps
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .view.slice(from, until) instead of .view(from, until)
- def withFilter(f: (B) => Boolean): Iterator[B]
- Implicit
- This member is added by an implicit conversion from Collect[A, B] toIterableOnceExtensionMethods[B] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
- Shadowing
- This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:(collect: IterableOnceExtensionMethods[B]).withFilter(f)
- Definition Classes
- IterableOnceExtensionMethods
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use .iterator.withFilter(...) instead
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
which are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collection
and its sub-packages contain Scala's collections frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect
- Scala's reflection API (scala-reflect.jar)scala.xml
- XML parsing, manipulation, and serialization (scala-xml.jar)scala.collection.parallel
- Parallel collections (scala-parallel-collections.jar)scala.util.parsing
- Parser combinators (scala-parser-combinators.jar)scala.swing
- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)Automatic imports
Identifiers in the scala package and the
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 forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.