scala.collection.GenSeqViewLike
A fall back which forces everything into a vector and then applies an operation on it.
The implementation base trait of this view.
Applies a binary operator to a start value and all elements of this collection, going left to right.
Applies a binary operator to a start value and all elements of this collection, going left to right.
Note: /:
is alternate syntax for foldLeft
; z /: xs
is the same as
xs foldLeft z
.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = (5 /: a)(_+_) b: Int = 15 scala> val c = (5 /: a)((x,y) => x + y) c: Int = 15
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this collection,
going left to right with the start value z
on the left:
op(...op(op(z, x_1), x_2), ..., x_n)
where x1, ..., xn
are the elements of this collection.
Applies a binary operator to all elements of this collection and a start value, going right to left.
Applies a binary operator to all elements of this collection and a start value, going right to left.
Note: :\
is alternate syntax for foldRight
; xs :\ z
is the same as
xs foldRight z
.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = (a :\ 5)(_+_) b: Int = 15 scala> val c = (a :\ 5)((x,y) => x + y) c: Int = 15
the result type of the binary operator.
the start value
the binary operator
the result of inserting op
between consecutive elements of this collection,
going right to left with the start value z
on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn
are the elements of this collection.
Aggregates the results of applying an operator to subsequent elements.
Aggregates the results of applying an operator to subsequent elements.
This is a more general form of fold
and reduce
. It has similar
semantics, but does not require the result to be a supertype of the
element type. It traverses the elements in different partitions
sequentially, using seqop
to update the result, and then applies
combop
to results from different partitions. The implementation of
this operation may operate on an arbitrary number of collection
partitions, so combop
may be invoked an arbitrary number of times.
For example, one might want to process some elements and then produce
a Set
. In this case, seqop
would process an element and append it
to the list, while combop
would concatenate two lists from different
partitions together. The initial value z
would be an empty set.
pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)
Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).
the type of accumulated results
the initial value for the accumulated result of the partition - this
will typically be the neutral element for the seqop
operator (e.g.
Nil
for list concatenation or 0
for summation)
an operator used to accumulate results within a partition
an associative operator used to combine results from different partitions
A method that should be called from every well-designed equals method that is open to be overridden in a subclass.
A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
the value being probed for possible equality
true if this instance can possibly equal that
, otherwise false
Tests whether every element of this collection relates to the corresponding element of another sequence by satisfying a test predicate.
Tests whether every element of this collection relates to the corresponding element of another sequence by satisfying a test predicate.
the type of the elements of that
the other sequence
the test predicate, which relates elements from both sequences
true
if both sequences have the same length and
p(x, y)
is true
for all corresponding elements x
of this collection
and y
of that
, otherwise false
.
Counts the number of elements in the collection which satisfy a predicate.
Counts the number of elements in the collection which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p
.
Builds a new collection from this collection without any duplicate elements.
Builds a new collection from this collection without any duplicate elements.
Note: will not terminate for infinite-sized collections.
A new collection which contains the first occurrence of every element of this collection.
Selects all elements except first n ones.
Selects all elements except first n ones.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the number of elements to drop from this collection.
a collection consisting of all elements of this collection except the first n
ones, or else the
empty collection, if this collection has less than n
elements.
Drops longest prefix of elements that satisfy a predicate.
Drops longest prefix of elements that satisfy a predicate.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The predicate used to test elements.
the longest suffix of this collection whose first element
does not satisfy the predicate p
.
Tests whether this collection ends with the given sequence.
Tests whether this collection ends with the given sequence.
Note: will not terminate for infinite-sized collections.
the sequence to test
true
if this collection has that
as a suffix, false
otherwise.
Selects all elements of this collection which satisfy a predicate.
Selects all elements of this collection which satisfy a predicate.
the predicate used to test elements.
a new collection consisting of all elements of this collection that satisfy the given
predicate p
. Their order may not be preserved.
Selects all elements of this collection which do not satisfy a predicate.
Selects all elements of this collection which do not satisfy a predicate.
the predicate used to test elements.
a new collection consisting of all elements of this collection that do not satisfy the given
predicate p
. Their order may not be preserved.
Finds the first element of the collection satisfying a predicate, if any.
Finds the first element of the collection 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.
the predicate used to test elements.
an option value containing the first element in the collection
that satisfies p
, or None
if none exists.
Folds the elements of this collection using the specified associative binary operator.
Folds the elements of this collection using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
a type parameter for the binary operator, a supertype of A
.
a neutral element for the fold operation; may be added to the result
an arbitrary number of times, and must not change the result (e.g., Nil
for list concatenation,
0 for addition, or 1 for multiplication.)
a binary operator that must be associative
the result of applying fold operator op
between all the elements and z
Applies a binary operator to a start value and all elements of this collection, going left to right.
Applies a binary operator to a start value and all elements of this collection, going left to right.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this collection,
going left to right with the start value z
on the left:
op(...op(z, x_1), x_2, ..., x_n)
where x1, ..., xn
are the elements of this collection.
Applies a binary operator to all elements of this collection and a start value, going right to left.
Applies a binary operator to all elements of this collection and a start value, going right to left.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this collection,
going right to left with the start value z
on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn
are the elements of this collection.
Partitions this collection into a map of collections according to some discriminator function.
Partitions this collection into a map of collections according to some discriminator function.
Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new collection.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to collections such that the following invariant holds:
(xs partition f)(k) = xs filter (x => f(x) == k)
That is, every key k
is bound to a collection of those elements x
for which f(x)
equals k
.
Selects the first element of this collection.
Selects the first element of this collection.
the first element of this collection.
if the collection is empty.
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.
the first element of this collection if it is nonempty,
None
if it is empty.
Finds index of the first element satisfying some predicate after or at some start index.
Finds index of the first element satisfying some predicate after or at some start index.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
the start index
the index >= from
of the first element of this collection that satisfies the predicate p
,
or -1
, if none exists.
Selects all elements except the last.
Selects all elements except the last.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a collection consisting of all elements of this collection except the last one.
if the collection is empty.
Tests whether this collection can be repeatedly traversed.
Tests whether this collection can be repeatedly traversed.
true
Selects the last element.
Selects the last element.
Note: might return different results for different runs, unless the underlying collection type is ordered.
The last element of this collection.
If the collection is empty.
Finds index of last element satisfying some predicate before or at given end index.
Finds index of last element satisfying some predicate before or at given end index.
the predicate used to test elements.
the index <= end
of the last element of this collection that satisfies the predicate p
,
or -1
, if none exists.
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.
the last element of this collection$ if it is nonempty,
None
if it is empty.
Displays all elements of this collection in a string.
Displays all elements of this collection in a string.
a string representation of this collection. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this collection follow each other without any
separator string.
Displays all elements of this collection in a string using a separator string.
Displays all elements of this collection in a string using a separator string.
the separator string.
a string representation of this collection. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this collection are separated by the string sep
.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this collection in a string using start, end, and separator strings.
Displays all elements of this collection in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this collection. The resulting string
begins with the string start
and ends with the string
end
. Inside, the string representations (w.r.t. the method
toString
) of all elements of this collection are separated by
the string sep
.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Tests whether the collection is not empty.
Tests whether the collection is not empty.
true
if the collection contains at least one element, false
otherwise.
The default par
implementation uses the combiner provided by this method
to create a new parallel collection.
The default par
implementation uses the combiner provided by this method
to create a new parallel collection.
a combiner for the parallel collection of type ParRepr
Partitions this collection in two collections according to a predicate.
Partitions this collection in two collections according to a predicate.
the predicate on which to partition.
a pair of collections: the first collection consists of all elements that
satisfy the predicate p
and the second collection consists of all elements
that don't. The relative order of the elements in the resulting collections
may not be preserved.
Reduces the elements of this collection using the specified associative binary operator.
Reduces the elements of this collection using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A
.
A binary operator that must be associative.
The result of applying reduce operator op
between all the elements if the collection is nonempty.
if this collection is empty.
Optionally applies a binary operator to all elements of this collection, going left to right.
Optionally applies a binary operator to all elements of this collection, going left to right.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceLeft(op)
is this collection is nonempty,
None
otherwise.
Reduces the elements of this collection, if any, using the specified associative binary operator.
Reduces the elements of this collection, if any, using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A
.
A binary operator that must be associative.
An option value containing result of applying reduce operator op
between all
the elements if the collection is nonempty, and None
otherwise.
Applies a binary operator to all elements of this collection, going right to left.
Applies a binary operator to all elements of this collection, going right to left.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
the result of inserting op
between consecutive elements of this collection,
going right to left:
op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))
where x1, ..., xn
are the elements of this collection.
if this collection is empty.
Optionally applies a binary operator to all elements of this collection, going right to left.
Optionally applies a binary operator to all elements of this collection, going right to left.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceRight(op)
is this collection is nonempty,
None
otherwise.
Returns new collection wih elements in reversed order.
Returns new collection wih elements in reversed order.
Note: will not terminate for infinite-sized collections.
A new collection with all elements of this collection in reversed order.
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.
element type of the resulting collection
type of the resulting collection
neutral element for the operator op
the associative operator for the scan
combiner factory which provides a combiner
a new collection containing the prefix scan of the elements in this collection
Produces a collection containing cumulative results of applying the operator going left to right.
Produces a collection containing cumulative results of applying the operator going left to right.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the elements in the resulting collection
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
collection with intermediate results
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.
Example:
List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
the type of the elements in the resulting collection
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom
which determines
the result class That
from the current representation type Repr
and
and the new element type B
.
collection with intermediate results
(Changed in version 2.9.0) The behavior of scanRight
has changed. The previous behavior can be reproduced with scanRight.reverse.
Computes length of longest segment whose elements all satisfy some predicate.
Computes length of longest segment whose elements all satisfy some predicate.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
the index where the search starts.
the length of the longest segment of this collection starting from index from
such that every element of the segment satisfies the predicate p
.
The size of this collection.
The size of this collection.
Note: will not terminate for infinite-sized collections.
the number of elements in this collection.
Selects an interval of elements.
Selects an interval of elements. The returned collection is made up
of all elements x
which satisfy the invariant:
from <= indexOf(x) < until
Note: might return different results for different runs, unless the underlying collection type is ordered.
the lowest index to include from this collection.
the lowest index to EXCLUDE from this collection.
a collection containing the elements greater than or equal to
index from
extending up to (but not including) index until
of this collection.
Splits this collection into a prefix/suffix pair according to a predicate.
Splits this collection into a prefix/suffix pair according to a predicate.
Note: c span p
is equivalent to (but possibly more efficient than)
(c takeWhile p, c dropWhile p)
, provided the evaluation of the
predicate p
does not cause any side-effects.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the test predicate
a pair consisting of the longest prefix of this collection whose
elements all satisfy p
, and the rest of this collection.
Splits this collection into two at a given position.
Splits this collection into two at a given position.
Note: c splitAt n
is equivalent to (but possibly more efficient than)
(c take n, c drop n)
.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the position at which to split.
a pair of collections consisting of the first n
elements of this collection, and the other elements.
Tests whether this collection contains the given sequence at a given index.
Tests whether this collection contains the given sequence at a given index.
Note: If the both the receiver object this
and the argument
that
are infinite sequences this method may not terminate.
the sequence to test
the index where the sequence is searched.
true
if the sequence that
is contained in this collection at
index offset
, otherwise false
.
Selects all elements except the first.
Selects all elements except the first.
Note: might return different results for different runs, unless the underlying collection type is ordered.
a collection consisting of all elements of this collection except the first one.
if the collection is empty.
Selects first n elements.
Selects first n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the number of elements to take from this collection.
a collection consisting only of the first n
elements of this collection,
or else the whole collection, if it has less than n
elements.
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.
The predicate used to test elements.
the longest prefix of this collection whose elements all satisfy
the predicate p
.
Converts this collection to a mutable buffer.
Converts this collection to a mutable buffer.
Note: will not terminate for infinite-sized collections.
a buffer containing all elements of this collection.
Converts this collection to an indexed sequence.
Converts this collection to an indexed sequence.
Note: will not terminate for infinite-sized collections.
an indexed sequence containing all elements of this collection.
Converts this collection to an iterable collection.
Converts this collection to an iterable collection. Note that
the choice of target Iterable
is lazy in this default implementation
as this TraversableOnce
may be lazy and unevaluated (i.e. it may
be an iterator which is only traversable once).
Note: will not terminate for infinite-sized collections.
an Iterable
containing all elements of this collection.
Returns an Iterator over the elements in this collection.
Returns an Iterator over the elements in this collection. Will return the same Iterator if this instance is already an Iterator.
Note: will not terminate for infinite-sized collections.
an Iterator containing all elements of this collection.
Converts this collection to a list.
Converts this collection to a list.
Note: will not terminate for infinite-sized collections.
a list containing all elements of this collection.
Converts this collection to a sequence.
Converts this collection to a sequence. As with toIterable
, it's lazy
in this default implementation, as this TraversableOnce
may be
lazy and unevaluated.
Note: will not terminate for infinite-sized collections.
a sequence containing all elements of this collection.
Converts this collection to a set.
Converts this collection to a set.
Note: will not terminate for infinite-sized collections.
a set containing all elements of this collection.
Converts this collection to a stream.
Converts this collection to a stream.
Note: will not terminate for infinite-sized collections.
a stream containing all elements of this collection.
Converts this collection to an unspecified Traversable.
Converts this collection to an unspecified Traversable. Will return the same collection if this instance is already Traversable.
Note: will not terminate for infinite-sized collections.
a Traversable containing all elements of this collection.
Converts this collection to a Vector.
Converts this collection to a Vector.
Note: will not terminate for infinite-sized collections.
a vector containing all elements of this collection.
Test two objects for inequality.
Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types and null
.
Equivalent to x.hashCode
except for boxed numeric types and null
.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null
returns a hashcode where null.hashCode
throws a
NullPointerException
.
a hash value consistent with ==
[use case] Returns a new collection containing the elements from the left hand operand followed by the elements from the right hand operand.
Returns a new collection containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the collection is the most specific superclass encompassing the element types of the two operands.
Example:
scala> val a = LinkedList(1) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1) scala> val b = LinkedList(2) b: scala.collection.mutable.LinkedList[Int] = LinkedList(2) scala> val c = a ++ b c: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2) scala> val d = LinkedList('a') d: scala.collection.mutable.LinkedList[Char] = LinkedList(a) scala> val e = c ++ d e: scala.collection.mutable.LinkedList[AnyVal] = LinkedList(1, 2, a)
the element type of the returned collection.
the traversable to append.
a new collection which contains all elements of this collection
followed by all elements of that
.
[use case] A copy of the collection with an element prepended.
A copy of the collection with an element prepended.
Note that :-ending operators are right associative (see example).
A mnemonic for +:
vs. :+
is: the COLon goes on the COLlection side.
Also, the original collection is not modified, so you will want to capture the result.
Example:
scala> val x = LinkedList(1) x: scala.collection.mutable.LinkedList[Int] = LinkedList(1) scala> val y = 2 +: x y: scala.collection.mutable.LinkedList[Int] = LinkedList(2, 1) scala> println(x) LinkedList(1)
the prepended element
a new collection consisting of elem
followed
by all elements of this collection.
[use case] A copy of this collection with an element appended.
A copy of this collection with an element appended.
A mnemonic for +:
vs. :+
is: the COLon goes on the COLlection side.
Note: will not terminate for infinite-sized collections.
Example:
scala> import scala.collection.mutable.LinkedList import scala.collection.mutable.LinkedList scala> val a = LinkedList(1) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1) scala> val b = a :+ 2 b: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2) scala> println(a) LinkedList(1)
the appended element
a new collection consisting of
all elements of this collection followed by elem
.
Test two objects for equality.
Test two objects for equality.
The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
true
if the receiver object is equivalent to the argument; false
otherwise.
Selects an element by its index in the collection.
Selects an element by its index in the collection.
Example:
scala> val x = LinkedList(1, 2, 3, 4, 5) x: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4, 5) scala> x(3) res1: Int = 4
The index to select.
the element of this collection at index idx
, where 0
indicates the first element.
if idx
does not satisfy 0 <= idx < length
.
Cast the receiver object to be of type T0
.
Cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String]
will throw a ClassCastException
at
runtime, while the expression List(1).asInstanceOf[List[String]]
will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
if the receiver object is not an instance of the erasure of type T0
.
Create a copy of the receiver object.
[use case] Builds a new collection by applying a partial function to all elements of this collection on which the function is defined.
Builds a new collection by applying a partial function to all elements of this collection on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the collection.
a new collection 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.
The factory companion object that builds instances of class CC.
The factory companion object that builds instances of class CC.
(or its Iterable
superclass where class CC is not a Seq
.)
[use case] Copies values of this collection to an array.
Copies values of this collection to an array.
Fills the given array xs
with values of this collection, beginning at index start
.
Copying will stop once either the end of the current collection is reached,
or the end of the array is reached.
Note: will not terminate for infinite-sized collections.
the array to fill.
the starting index.
[use case] Copies values of this collection to an array.
Copies values of this collection to an array.
Fills the given array xs
with values of this collection.
Copying will stop once either the end of the current collection is reached,
or the end of the array is reached.
Note: will not terminate for infinite-sized collections.
the array to fill.
[use case] Computes the multiset difference between this collection and another sequence.
Computes the multiset difference between this collection and another sequence.
Note: will not terminate for infinite-sized collections.
the sequence of elements to remove
a new collection which contains all elements of this collection
except some of occurrences of elements that also appear in that
.
If an element value x
appears
n times in that
, then the first n occurrences of x
will not form
part of the result, but any following occurrences will.
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
The eq
method implements an equivalence relation on
non-null instances of AnyRef
, and has three additional properties:
x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.null.eq(null)
returns true
. When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
true
if the argument is a reference to the receiver object; false
otherwise.
The equals method for arbitrary sequences.
The equals method for arbitrary sequences. Compares this sequence to some other object.
The object to compare the sequence to
true
if that
is a sequence that has the same elements as
this sequence in the same order, false
otherwise
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize
method is invoked, as
well as the interaction between finalize
and non-local returns
and exceptions, are all platform dependent.
[use case] Builds a new collection by applying a function to all elements of this collection and using the elements of the resulting collections.
Builds a new collection by applying a function to all elements of this collection 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 collection. This might cause unexpected results sometimes. For example:
// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet) // lettersOf will return a Set[Char], not a Seq def lettersOf(words: Seq[String]) = words.toSet flatMap (word => word.toSeq) // xs will be a 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)
the element type of the returned collection.
the function to apply to each element.
a new collection resulting from applying the given collection-valued function
f
to each element of this collection and concatenating the results.
[use case] Converts this collection of traversable collections into a collection formed by the elements of these traversable collections.
Converts this collection of traversable collections into a collection formed by the elements of these traversable collections.
The resulting collection's type will be guided by the static type of collection. For example:
val xs = List(Set(1, 2, 3), Set(1, 2, 3)) // xs == List(1, 2, 3, 1, 2, 3) val ys = Set(List(1, 2, 3), List(3, 2, 1)) // ys == Set(1, 2, 3)
the type of the elements of each traversable collection.
a new collection resulting from concatenating all element collections.
[use case]
the function that is applied for its side-effect to every element.
The result of function f
is discarded.
Returns string formatted according to given format
string.
Returns string formatted according to given format
string.
Format strings are as for String.format
(@see java.lang.String.format).
The generic builder that builds instances of CC at arbitrary element types.
The generic builder that builds instances of CC at arbitrary element types.
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
Hashcodes for CC produce a value from the hashcodes of all the elements of the collection.
Hashcodes for CC produce a value from the hashcodes of all the elements of the collection.
the hash code value for this object.
[use case] Finds index of first occurrence of some value in this collection after or at some start index.
Finds index of first occurrence of some value in this collection after or at some start index.
Note: may not terminate for infinite-sized collections.
the element value to search for.
the start index
the index >= from
of the first element of this collection that is equal (as determined by ==
)
to elem
, or -1
, if none exists.
[use case] Finds index of first occurrence of some value in this collection.
Finds index of first occurrence of some value in this collection.
Note: may not terminate for infinite-sized collections.
the element value to search for.
the index of the first element of this collection that is equal (as determined by ==
)
to elem
, or -1
, if none exists.
Finds index of first element satisfying some predicate.
Finds index of first element satisfying some predicate.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
the index of the first element of this collection that satisfies the predicate p
,
or -1
, if none exists.
[use case] Computes the multiset intersection between this collection and another sequence.
Computes the multiset intersection between this collection and another sequence.
Note: may not terminate for infinite-sized collections.
the sequence of elements to intersect with.
a new collection which contains all elements of this collection
which also appear in that
.
If an element value x
appears
n times in that
, then the first n occurrences of x
will be retained
in the result, but any following occurrences will be omitted.
Tests whether this collection contains given index.
Tests whether this collection contains given index.
The implementations of methods apply
and isDefinedAt
turn a Seq[A]
into
a PartialFunction[Int, A]
.
the index to test
true
if this collection contains an element at position idx
, false
otherwise.
Tests whether this collection is empty.
Tests whether this collection is empty.
true
if the collection contain no elements, false
otherwise.
Test whether the dynamic type of the receiver object is T0
.
Test whether the dynamic type of the receiver object is T0
.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String]
will return false
, while the
expression List(1).isInstanceOf[List[String]]
will return true
.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
[use case] Finds index of last occurrence of some value in this collection before or at a given end index.
Finds index of last occurrence of some value in this collection before or at a given end index.
the element value to search for.
the end index.
the index <= end
of the last element of this collection that is equal (as determined by ==
)
to elem
, or -1
, if none exists.
[use case] Finds index of last occurrence of some value in this collection.
Finds index of last occurrence of some value in this collection.
Note: will not terminate for infinite-sized collections.
the element value to search for.
the index of the last element of this collection that is equal (as determined by ==
)
to elem
, or -1
, if none exists.
Finds index of last element satisfying some predicate.
Finds index of last element satisfying some predicate.
Note: will not terminate for infinite-sized collections.
the predicate used to test elements.
the index of the last element of this collection that satisfies the predicate p
,
or -1
, if none exists.
The length of the collection.
The length of the collection.
Note: will not terminate for infinite-sized collections.
Note: xs.length
and xs.size
yield the same result.
the number of elements in this collection.
[use case] Builds a new collection by applying a function to all elements of this collection.
Builds a new collection by applying a function to all elements of this collection.
the element type of the returned collection.
the function to apply to each element.
a new collection resulting from applying the given function
f
to each element of this collection and collecting the results.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this collection.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this collection
Equivalent to !(this eq that)
.
Equivalent to !(this eq that)
.
true
if the argument is not a reference to the receiver object; false
otherwise.
The builder that builds instances of type CC[A]
The builder that builds instances of type CC[A]
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
[use case] A copy of this collection with an element value appended until a given target length is reached.
A copy of this collection with an element value appended until a given target length is reached.
the target length
the padding value
a new collection consisting of
all elements of this collection followed by the minimal number of occurrences of elem
so
that the resulting collection has a length of at least len
.
Returns a parallel implementation of this collection.
Returns a parallel implementation of this collection.
For most collection types, this method creates a new parallel collection by copying
all the elements. For these collection, par
takes linear time. Mutable collections
in this category do not produce a mutable parallel collection that has the same
underlying dataset, so changes in one collection will not be reflected in the other one.
Specific collections (e.g. ParArray
or mutable.ParHashMap
) override this default
behaviour by creating a parallel collection which shares the same underlying dataset.
For these collections, par
takes constant or sublinear time.
All parallel collections return a reference to themselves.
a parallel implementation of this collection
[use case] Produces a new collection where a slice of elements in this collection is replaced by another sequence.
Produces a new collection where a slice of elements in this collection is replaced by another sequence.
the index of the first replaced element
the number of elements to drop in the original collection
a new collection consisting of all elements of this collection
except that replaced
elements starting from from
are replaced
by patch
.
Returns the length of the longest prefix whose elements all satisfy some predicate.
Returns the length of the longest prefix whose elements all satisfy some predicate.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
the length of the longest prefix of this collection
such that every element of the segment satisfies the predicate p
.
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements in this collection of numbers of type Int
.
Instead of Int
, any other type T
with an implicit Numeric[T]
implementation
can be used as element type of the collection and as result type of product
.
Examples of such types are: Long
, Float
, Double
, BigInt
.
[use case] Builds a new collection by applying a function to all elements of this collection and collecting the results in reversed order.
Builds a new collection by applying a function to all elements of this collection and collecting the results in reversed order.
Note: will not terminate for infinite-sized collections.
Note: xs.reverseMap(f)
is the same as xs.reverse.map(f)
but might be more efficient.
the element type of the returned collection.
the function to apply to each element.
a new collection resulting from applying the given function
f
to each element of this collection and collecting the results in reversed order.
[use case] Checks if the other iterable collection contains the same elements in the same order as this collection.
Checks if the other iterable collection contains the same elements in the same order as this collection.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Note: will not terminate for infinite-sized collections.
the collection to compare with.
true
, if both collections contain the same elements in the same order, false
otherwise.
Tests whether this collection starts with the given sequence.
Tests whether this collection starts with the given sequence.
the sequence to test
true
if this collection has that
as a prefix, false
otherwise.
Defines the prefix of this object's toString
representation.
Defines the prefix of this object's toString
representation.
a string representation which starts the result of toString
applied to this collection. By default the string prefix is the
simple name of the collection class collection.
[use case] Sums up the elements of this collection.
Sums up the elements of this collection.
the sum of all elements in this collection of numbers of type Int
.
Instead of Int
, any other type T
with an implicit Numeric[T]
implementation
can be used as element type of the collection and as result type of sum
.
Examples of such types are: Long
, Float
, Double
, BigInt
.
[use case] Converts this collection into another by copying all elements.
Converts this collection into another by copying all elements.
Note: will not terminate for infinite-sized collections.
The collection type to build.
a new collection containing all elements of this collection.
[use case] Converts this collection to an array.
Converts this collection to an array.
Note: will not terminate for infinite-sized collections.
an array containing all elements of this collection.
An ClassTag
must be available for the element type of this collection.
[use case] Converts this collection to a map.
Converts this collection to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.
Note: will not terminate for infinite-sized collections.
a map of type immutable.Map[T, U]
containing all key/value pairs of type (T, U)
of this collection.
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
Transposes this collection of traversable collections into a collection of collections.
Transposes this collection of traversable collections into a collection of collections.
the type of the elements of each traversable collection.
an implicit conversion which asserts that the
element type of this collection is a Traversable
.
a two-dimensional collection of collections which has as nth row the nth column of this collection.
(Changed in version 2.9.0) transpose
throws an IllegalArgumentException
if collections are not uniformly sized.
if all collections in this collection are not of the same size.
[use case] Produces a new sequence which contains all elements of this collection and also all elements of a given sequence.
Produces a new sequence which contains all elements of this collection and also all elements of
a given sequence. xs union ys
is equivalent to xs ++ ys
.
Another way to express this
is that xs union ys
computes the order-presevring multi-set union of xs
and ys
.
union
is hence a counter-part of diff
and intersect
which also work on multi-sets.
Note: will not terminate for infinite-sized collections.
the sequence to add.
a new collection which contains all elements of this collection
followed by all elements of that
.
Converts this collection of pairs into two collections of the first and second half of each pair.
Converts this collection of pairs into two collections of the first and second half of each pair.
the type of the first half of the element pairs
the type of the second half of the element pairs
an implicit conversion which asserts that the element type of this collection is a pair.
a pair collections, containing the first, respectively second half of each element pair of this collection.
Converts this collection of triples into three collections of the first, second, and third element of each triple.
Converts this collection of triples into three collections of the first, second, and third element of each triple.
the type of the first member of the element triples
the type of the second member of the element triples
the type of the third member of the element triples
an implicit conversion which asserts that the element type of this collection is a triple.
a triple collections, containing the first, second, respectively third member of each element triple of this collection.
[use case] A copy of this collection with one single replaced element.
A copy of this collection with one single replaced element.
the position of the replacement
the replacing element
a copy of this collection with the element at position index
replaced by elem
.
[use case] Returns a collection formed from this collection and another iterable collection by combining corresponding elements in pairs.
Returns a collection formed from this collection 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.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the second half of the returned pairs
The iterable providing the second half of each result pair
a new collection containing pairs consisting of
corresponding elements of this collection and that
. The length
of the returned collection is the minimum of the lengths of this collection and that
.
[use case] Returns a collection formed from this collection and another iterable collection by combining corresponding elements in pairs.
Returns a collection formed from this collection 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.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the second half of the returned pairs
The iterable providing the second half of each result pair
the element to be used to fill up the result if this collection is shorter than that
.
the element to be used to fill up the result if that
is shorter than this collection.
a new collection containing pairs consisting of
corresponding elements of this collection and that
. The length
of the returned collection is the maximum of the lengths of this collection and that
.
If this collection is shorter than that
, thisElem
values are used to pad the result.
If that
is shorter than this collection, thatElem
values are used to pad the result.
[use case] Zips this collection with its indices.
Zips this collection with its indices.
Note: might return different results for different runs, unless the underlying collection type is ordered.
A new collection containing pairs consisting of all elements of this
collection paired with their index. Indices start at 0
.
List("a", "b", "c").zipWithIndex = List(("a", 0), ("b", 1), ("c", 2))
(patched: StringAdd).self
(patched: StringFormat).self
A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold
.
Example:
scala> val a = LinkedList(1,2,3,4) a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4) scala> val b = (a /:\ 5)(_+_) b: Int = 15
(Since version 2.10.0) use fold instead
(patched: ArrowAssoc[Patched[B]]).x
(Since version 2.10.0) Use leftOfArrow
instead
(patched: Ensuring[Patched[B]]).x
(Since version 2.10.0) Use resultOfEnsuring
instead