The type implementing this traversable
The type implementing this traversable
A class supporting filtered operations.
Applies a function f to all elements of this collection.
Applies a function f to all elements of this collection.
the type parameter describing the result of function f.
This result will always be ignored. Typically U is Unit,
but this is not necessary.
the function that is applied for its side-effect to every element.
The result of function f is discarded.
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.
Equivalent to x.hashCode except for boxed numeric types.
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.
a hash value consistent with ==
[use case] Concatenates this collection with the elements of a traversable collection.
Concatenates this collection with the elements of a traversable collection.
the element type of the returned collection.
the traversable to append.
a new collection of type That which contains all elements
of this collection followed by all elements of that.
Concatenates this collection with the elements of a traversable collection.
Concatenates this collection with the elements of a traversable collection.
the element type of the returned collection.
the class of the returned collection. Where possible, That is
the same class as the current collection class Repr, but this
depends on the element type B being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, B, That]
is found.
the traversable to append.
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.
a new collection of type That which contains all elements
of this collection followed by all elements of that.
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions.
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions. Since TraversableOnce has no '++' method, we have to implement that directly, but Traversable and down can use the overload.
[use case] Concatenates this collection with the elements of a traversable collection.
Concatenates this collection with the elements of a traversable collection. It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one.
the element type of the returned collection.
the traversable to append.
a new collection of type That which contains all elements
of this collection followed by all elements of that.
Concatenates this collection with the elements of a traversable collection.
Concatenates this collection with the elements of a traversable collection. It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one.
the element type of the returned collection.
the class of the returned collection. Where possible, That is
the same class as the current collection class Repr, but this
depends on the element type B being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, B, That]
is found.
the traversable to append.
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.
a new collection of type That which contains all elements
of this collection followed by all elements of that.
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.
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 x,,1,,, ..., x,,n,, are the elements of this collection.
A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold.
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.
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 x,,1,,, ..., x,,n,, are the elements of this collection.
Test two objects for equality.
Test two objects for equality.
true if the receiver object is equivalent to the argument; false otherwise.
Appends all elements of this collection to a string builder.
Appends all elements of this collection to a string builder.
The written text consists of the string representations (w.r.t. the method
toString) of all elements of this collection without any separator string.
the string builder to which elements are appended.
the string builder b to which elements were appended.
Appends all elements of this collection to a string builder using a separator string.
Appends all elements of this collection 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 collection, separated by the
string sep.
the string builder to which elements are appended.
the separator string.
the string builder b to which elements were appended.
Appends all elements of this collection to a string builder using start, end, and separator strings.
Appends all elements of this collection to a string builder using start, end,
and separator strings.
The written text begins with the string start and ends with the string
end. Inside, the string representations (w.r.t. the method toString)
of all elements of this collection are separated by the string sep.
the string builder to which elements are appended.
the starting string.
the separator string.
the ending string.
the string builder b to which elements were appended.
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 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 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
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.
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 of type That resulting from applying the partial function
pf to each element on which it is defined and collecting the results.
The order of the elements is preserved.
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 class of the returned collection. Where possible, That is
the same class as the current collection class Repr, but this
depends on the element type B being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, B, That]
is found.
the partial function which filters and maps the collection.
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.
a new collection of type That resulting from applying the partial function
pf to each element on which it is defined and collecting the results.
The order of the elements is preserved.
Finds the first element of the collection for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the collection 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.
the partial function
an option value containing pf applied to the first
value for which it is defined, or None if none exists.
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
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 elements of this collection to an array.
Copies elements of this collection to an array.
Fills the given array xs with at most len elements of
this collection, starting at position start.
Copying will stop once either the end of the current collection is reached,
or the end of the array is reached, or len elements have been copied.
the array to fill.
the starting index.
the maximal number of elements to copy.
Copies elements of this collection to an array.
Copies elements of this collection to an array.
Fills the given array xs with at most len elements of
this collection, starting at position start.
Copying will stop once either the end of the current collection is reached,
or the end of the array is reached, or len elements have been copied.
Note: will not terminate for infinite-sized collections.
the type of the elements of the array.
the array to fill.
the starting index.
the maximal number of elements to copy.
[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.
the array to fill.
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 type of the elements of the array.
the array to fill.
[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.
the array to fill.
the starting index.
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 type of the elements of the array.
the array to fill.
the starting index.
Copies all elements of this collection to a buffer.
Copies all elements of this collection to a buffer.
Note: will not terminate for infinite-sized collections.
The buffer to which elements are copied.
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.
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 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 equality method for reference types.
Tests whether a predicate holds for some of the elements of this collection.
Tests whether a predicate holds for some of the elements of this collection.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
true if the given predicate p holds for some of the
elements of this collection, otherwise false.
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. The order of the elements is 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. The order of the elements is preserved.
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.
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.
[use case] Builds a new collection by applying a function to all elements of this collection and concatenating the results.
Builds a new collection by applying a function to all elements of this collection and concatenating the results.
the element type of the returned collection.
the function to apply to each element.
a new collection of type That resulting from applying the given collection-valued function
f to each element of this collection and concatenating the results.
Builds a new collection by applying a function to all elements of this collection and concatenating the results.
Builds a new collection by applying a function to all elements of this collection and concatenating the results.
the element type of the returned collection.
the class of the returned collection. Where possible, That is
the same class as the current collection class Repr, but this
depends on the element type B being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, B, That]
is found.
the function to apply to each 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.
a new collection of type That 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 in which all element collections are concatenated.
Converts this collection of traversable collections into a collection in which all element collections are concatenated.
the type of the elements of each traversable collection.
a new collection resulting from concatenating all element collections.
Converts this collection of traversable collections into a collection in which all element collections are concatenated.
Converts this collection of traversable collections into a collection in which all element collections are concatenated.
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 new collection resulting from concatenating all element collections.
Folds the elements of this sequence using the specified associative binary operator.
Folds the elements of this sequence using the specified associative binary operator. The order in which the elements are reduced is unspecified and may be nondeterministic.
Note this method has a different signature than the foldLeft
and foldRight methods of the trait Traversable.
The result of folding may only be a supertype of this parallel collection's
type parameter T.
a neutral element for the fold operation, it may be added to the result
an arbitrary number of times, not changing 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 x,,1,,, ..., x,,n,, 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 x,,1,,, ..., x,,n,, are the elements of this collection.
Tests whether a predicate holds for all elements of this collection.
Tests whether a predicate holds for all elements of this collection.
Note: may not terminate for infinite-sized collections.
the predicate used to test elements.
true if the given predicate p holds for all elements
of this collection, otherwise false.
[use case] Applies a function f to all elements of this collection.
Applies a function f to all elements of this collection.
the function that is applied for its side-effect to every element.
The result of function f is discarded.
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.
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.
Tests whether this collection is known to have a finite size.
Tests whether this collection 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 returns true if all elements have been computed.
It returns false if the stream is not yet evaluated to the end.
Note: many collection methods will not work on collections of infinite sizes.
true if this collection is known to have finite size, false otherwise.
The hashCode method for reference types.
Selects the first element of this collection.
Selects the first element of this collection.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the first element of this collection.
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.
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.
Iterates over the inits of this collection.
Iterates over the inits of this collection. The first value will be this
collection and the final one will be an empty collection, with the intervening
values the results of successive applications of init.
an iterator over all the inits of this collection
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
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.
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.
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.
[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 of type That resulting from applying the given function
f to each element of this collection and collecting the results.
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 class of the returned collection. Where possible, That is
the same class as the current collection class Repr, but this
depends on the element type B being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, B, That]
is found.
the function to apply to each 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.
a new collection of type That 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 with respect to the ordering cmp.
Finds the largest element.
Finds the largest element.
The type over which the ordering is defined.
An ordering to be used for comparing elements.
the largest element of this collection with respect to the ordering cmp.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this collection with respect to the ordering cmp.
Finds the smallest element.
Finds the smallest element.
The type over which the ordering is defined.
An ordering to be used for comparing elements.
the smallest element of this collection with respect to the ordering cmp.
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)"
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]
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.
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.
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.
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
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
is the same as in the original collection.
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements of this collection with respect to the * operator in num.
Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the result type of the * operator.
an implicit parameter defining a set of numeric operations
which includes the * operator to be used in forming the product.
the product of all elements of this collection with respect to the * operator in num.
Reduces the elements of this sequence using the specified associative binary operator.
Reduces the elements of this sequence using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
Note this method has a different signature than the reduceLeft
and reduceRight methods of the trait Traversable.
The result of reducing may only be a supertype of this parallel collection's
type parameter T.
A binary operator that must be associative.
The result of applying reduce operator op between all the elements if the collection is nonempty.
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.
Optionally reduces the elements of this sequence using the specified associative binary operator.
Optionally reduces the elements of this sequence using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
Note this method has a different signature than the reduceLeftOption
and reduceRightOption methods of the trait Traversable.
The result of reducing may only be a supertype of this parallel collection's
type parameter T.
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 x,,1,,, ..., x,,n,, are the elements of this collection.
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.
The collection of type collection underlying this TraversableLike object.
The collection of type collection underlying this TraversableLike object.
By default this is implemented as the TraversableLike object itself,
but this can be overridden.
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 cummulative results of applying the operator going left to right.
Produces a collection containing cummulative 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 cummulative results of applying the operator going right to left.
Produces a collection containing cummulative results of applying the operator going right to left. The head of the collection is the last cummulative 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
"This scanRight definition has changed in 2.9.\n" + "The previous behavior can be reproduced with scanRight.reverse."
A version of this collection with all of the operations implemented sequentially (i.
A version of this collection with all of the operations implemented sequentially (i.e. in a single-threaded manner).
This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.
a sequential view of the collection.
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 highest 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.
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 of this collection with respect to the + operator in num.
Sums up the elements of this collection.
Sums up the elements of this collection.
the result type of the + operator.
an implicit parameter defining a set of numeric operations
which includes the + operator to be used in forming the sum.
the sum of all elements of this collection with respect to the + operator in num.
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.
Iterates over the tails of this collection.
Iterates over the tails of this collection. The first value will be this
collection and the final one will be an empty collection, with the intervening
values the results of successive applications of tail.
an iterator over all the tails of this collection
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Selects first n elements.
Selects first n elements.
Note: might return different results for different runs, unless the underlying collection type is ordered.
Tt 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.
The underlying collection seen as an instance of CC.
The underlying collection seen as an instance of CC.
By default this is implemented as the current collection object itself,
but this can be overridden.
[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.
Converts this collection to an array.
Converts this collection to an array.
Note: will not terminate for infinite-sized collections.
the type of the elements of the array. A ClassManifest for
this type must be available.
an array containing all elements of this collection.
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.
A conversion from collections of type Repr to CC objects.
A conversion from collections of type Repr to CC objects.
By default this is implemented as just a cast, but this can be overridden.
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.
[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 containing all elements of this collection.
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 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 a string.
Converts this collection to a string.
a string representation of this collection. By default this
string consists of the stringPrefix of this collection,
followed by all elements separated by commas and enclosed in parentheses.
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.
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.
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.
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.
a triple collections, containing the first, second, respectively third member of each element triple of this collection.
Creates a non-strict view of a slice of this collection.
Creates a non-strict view of a slice of this collection.
Note: the difference between view and slice is that view produces
a view of the current collection, whereas slice produces a new collection.
Note: view(from, to) is equivalent to view.slice(from, to)
Note: might return different results for different runs, unless the underlying collection type is ordered.
the index of the first element of the view
the index of the element following the view
a non-strict view of a slice of this collection, starting at index from
and extending up to (but not including) index until.
Creates a non-strict view of this collection.
Creates a non-strict view of this collection.
a non-strict view of this collection.
Creates a non-strict filter of this collection.
Creates a non-strict filter of this collection.
Note: the difference between c filter p and c withFilter p is that
the former creates a new collection, whereas the latter only
restricts the domain of subsequent map, flatMap, foreach,
and withFilter operations.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the predicate used to test elements.
an object of class WithFilter, which supports
map, flatMap, foreach, and withFilter operations.
All these operations apply to those elements of this collection which
satisfy the predicate p.
A trait for traversable collections that are guaranteed immutable.
This is a base trait of all kinds of immutable Scala collections. It implements the behavior common to all collections, in terms of a method
foreachwith signature:def foreach[U](f: Elem => U): UnitCollection classes mixing in this trait provide a concrete
foreachmethod which traverses all the elements contained in the collection, applying a given function to each. They also need to provide a methodnewBuilderwhich creates a builder for collections of the same kind.A traversable class might or might not have two properties: strictness and orderedness. Neither is represented as a type.
The instances of a strict collection class have all their elements computed before they can be used as values. By contrast, instances of a non-strict collection class may defer computation of some of their elements until after the instance is available as a value. A typical example of a non-strict collection class is a
scala.collection.immutable.Stream. A more general class of examples areTraversableViews.If a collection is an instance of an ordered collection class, traversing its elements with
foreachwill always visit elements in the same order, even for different runs of the program. If the class is not ordered,foreachcan visit elements in different orders for different runs (but it will keep the same order in the same run).'A typical example of a collection class which is not ordered is a
HashMapof objects. The traversal order for hash maps will depend on the hash codes of its elements, and these hash codes might differ from one run to the next. By contrast, aLinkedHashMapis ordered because it'sforeachmethod visits elements in the order they were inserted into theHashMap.