object Seq extends SeqFactory[Seq]
This object provides a set of operations to create
values.
The current default implementation of a Seq
Seq
is a List
.
- Source
- Seq.scala
- Alphabetic
- By Inheritance
- Seq
- SeqFactory
- TraversableFactory
- GenericSeqCompanion
- GenSeqFactory
- GenTraversableFactory
- GenericCompanion
- AnyRef
- Any
- Hide All
- Show All
- Public
- All
Type Members
-
type
Coll = Seq[_]
The underlying collection type with unknown element type
The underlying collection type with unknown element type
- Attributes
- protected[this]
- Definition Classes
- GenericCompanion
-
class
GenericCanBuildFrom
[A] extends CanBuildFrom[CC[_], A, CC[A]]
A generic implementation of the
CanBuildFrom
trait, which forwards all calls toapply(from)
to thegenericBuilder
method of collectionfrom
, and which forwards all calls ofapply()
to thenewBuilder
method of this factory.A generic implementation of the
CanBuildFrom
trait, which forwards all calls toapply(from)
to thegenericBuilder
method of collectionfrom
, and which forwards all calls ofapply()
to thenewBuilder
method of this factory.- Definition Classes
- GenTraversableFactory
Value Members
-
final
def
!=(arg0: Any): Boolean
Test two objects for inequality.
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
Equivalent to
x.hashCode
except for boxed numeric types andnull
.Equivalent to
x.hashCode
except for boxed numeric types andnull
. 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. Fornull
returns a hashcode wherenull.hashCode
throws aNullPointerException
.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
-
final
def
==(arg0: Any): Boolean
The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.The expression
x == that
is equivalent toif (x eq null) that eq null else x.equals(that)
.- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- AnyRef → Any
-
def
ReusableCBF: GenericCanBuildFrom[Nothing]
- Definition Classes
- GenTraversableFactory
-
def
apply[A](elems: A*): Seq[A]
Creates a collection with the specified elements.
Creates a collection with the specified elements.
- A
the type of the collection's elements
- elems
the elements of the created collection
- returns
a new collection with elements
elems
- Definition Classes
- GenericCompanion
-
final
def
asInstanceOf[T0]: T0
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 aClassCastException
at runtime, while the expressionList(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.- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
-
implicit
def
canBuildFrom[A]: CanBuildFrom[Coll, A, Seq[A]]
The standard
CanBuildFrom
instance forSeq
objects.The standard
CanBuildFrom
instance forSeq
objects. The created value is an instance of classGenericCanBuildFrom
, which forwards calls to create a new builder to thegenericBuilder
method of the requesting collection. -
def
clone(): AnyRef
Create a copy of the receiver object.
-
def
concat[A](xss: Traversable[A]*): Seq[A]
Concatenates all argument collections into a single collection.
Concatenates all argument collections into a single collection.
- xss
the collections that are to be concatenated.
- returns
the concatenation of all the collections.
- Definition Classes
- GenTraversableFactory
-
def
empty[A]: Seq[A]
An empty collection of type
CC
[A]An empty collection of type
CC
[A]- A
the type of the collection's elements
- Definition Classes
- GenericCompanion
-
final
def
eq(arg0: AnyRef): Boolean
Tests whether the argument (
that
) is a reference to the receiver object (this
).Tests whether the argument (
that
) is a reference to the receiver object (this
).The
eq
method implements an equivalence relation on non-null instances ofAnyRef
, and has three additional properties:- It is consistent: for any non-null instances
x
andy
of typeAnyRef
, multiple invocations ofx.eq(y)
consistently returnstrue
or consistently returnsfalse
. - For any non-null instance
x
of typeAnyRef
,x.eq(null)
andnull.eq(x)
returnsfalse
. null.eq(null)
returnstrue
.
When overriding the
equals
orhashCode
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
).- returns
true
if the argument is a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
- It is consistent: for any non-null instances
-
def
equals(arg0: Any): Boolean
The equality method for reference types.
-
def
fill[A](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(elem: ⇒ A): Seq[Seq[Seq[Seq[Seq[A]]]]]
Produces a five-dimensional collection containing the results of some element computation a number of times.
Produces a five-dimensional collection containing the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3nd dimension
- n4
the number of elements in the 4th dimension
- n5
the number of elements in the 5th dimension
- elem
the element computation
- returns
A collection that contains the results of
n1 x n2 x n3 x n4 x n5
evaluations ofelem
.
- Definition Classes
- GenTraversableFactory
-
def
fill[A](n1: Int, n2: Int, n3: Int, n4: Int)(elem: ⇒ A): Seq[Seq[Seq[Seq[A]]]]
Produces a four-dimensional collection containing the results of some element computation a number of times.
Produces a four-dimensional collection containing the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3nd dimension
- n4
the number of elements in the 4th dimension
- elem
the element computation
- returns
A collection that contains the results of
n1 x n2 x n3 x n4
evaluations ofelem
.
- Definition Classes
- GenTraversableFactory
-
def
fill[A](n1: Int, n2: Int, n3: Int)(elem: ⇒ A): Seq[Seq[Seq[A]]]
Produces a three-dimensional collection containing the results of some element computation a number of times.
Produces a three-dimensional collection containing the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3nd dimension
- elem
the element computation
- returns
A collection that contains the results of
n1 x n2 x n3
evaluations ofelem
.
- Definition Classes
- GenTraversableFactory
-
def
fill[A](n1: Int, n2: Int)(elem: ⇒ A): Seq[Seq[A]]
Produces a two-dimensional collection containing the results of some element computation a number of times.
Produces a two-dimensional collection containing the results of some element computation a number of times.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- elem
the element computation
- returns
A collection that contains the results of
n1 x n2
evaluations ofelem
.
- Definition Classes
- GenTraversableFactory
-
def
fill[A](n: Int)(elem: ⇒ A): Seq[A]
Produces a collection containing the results of some element computation a number of times.
Produces a collection containing the results of some element computation a number of times.
- n
the number of elements contained in the collection.
- elem
the element computation
- returns
A collection that contains the results of
n
evaluations ofelem
.
- Definition Classes
- GenTraversableFactory
-
def
finalize(): Unit
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 betweenfinalize
and non-local returns and exceptions, are all platform dependent. -
final
def
getClass(): Class[_]
Returns the runtime class representation of the object.
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
- Definition Classes
- AnyRef → Any
-
def
hashCode(): Int
The hashCode method for reference types.
-
final
def
isInstanceOf[T0]: Boolean
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 returnfalse
, while the expressionList(1).isInstanceOf[List[String]]
will returntrue
. 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.- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
-
def
iterate[A](start: A, len: Int)(f: (A) ⇒ A): Seq[A]
Produces a collection containing repeated applications of a function to a start value.
Produces a collection containing repeated applications of a function to a start value.
- start
the start value of the collection
- len
the number of elements contained in the collection
- f
the function that's repeatedly applied
- returns
a collection with
len
values in the sequencestart, f(start), f(f(start)), ...
- Definition Classes
- GenTraversableFactory
-
final
def
ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that)
.Equivalent to
!(this eq that)
.- returns
true
if the argument is not a reference to the receiver object;false
otherwise.
- Definition Classes
- AnyRef
-
def
newBuilder[A]: Builder[A, Seq[A]]
The default builder for
objects.Seq
The default builder for
objects.Seq
- A
the type of the sequence's elements
- Definition Classes
- Seq → GenericCompanion
-
final
def
notify(): Unit
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.
- Definition Classes
- AnyRef
- Note
not specified by SLS as a member of AnyRef
-
final
def
notifyAll(): Unit
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.
- Definition Classes
- AnyRef
- Note
not specified by SLS as a member of AnyRef
-
def
range[T](start: T, end: T, step: T)(implicit arg0: Integral[T]): Seq[T]
Produces a collection containing equally spaced values in some integer interval.
Produces a collection containing equally spaced values in some integer interval.
- start
the start value of the collection
- end
the end value of the collection (the first value NOT contained)
- step
the difference between successive elements of the collection (must be positive or negative)
- returns
a collection with values
start, start + step, ...
up to, but excludingend
- Definition Classes
- GenTraversableFactory
-
def
range[T](start: T, end: T)(implicit arg0: Integral[T]): Seq[T]
Produces a collection containing a sequence of increasing of integers.
Produces a collection containing a sequence of increasing of integers.
- start
the first element of the collection
- end
the end value of the collection (the first value NOT contained)
- returns
a collection with values
start, start + 1, ..., end - 1
- Definition Classes
- GenTraversableFactory
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
tabulate[A](n1: Int, n2: Int, n3: Int, n4: Int, n5: Int)(f: (Int, Int, Int, Int, Int) ⇒ A): Seq[Seq[Seq[Seq[Seq[A]]]]]
Produces a five-dimensional collection containing values of a given function over ranges of integer values starting from 0.
Produces a five-dimensional collection containing values of a given function over ranges of integer values starting from 0.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3nd dimension
- n4
the number of elements in the 4th dimension
- n5
the number of elements in the 5th dimension
- f
The function computing element values
- returns
A collection consisting of elements
f(i1, i2, i3, i4, i5)
for0 <= i1 < n1
,0 <= i2 < n2
,0 <= i3 < n3
,0 <= i4 < n4
, and0 <= i5 < n5
.
- Definition Classes
- GenTraversableFactory
-
def
tabulate[A](n1: Int, n2: Int, n3: Int, n4: Int)(f: (Int, Int, Int, Int) ⇒ A): Seq[Seq[Seq[Seq[A]]]]
Produces a four-dimensional collection containing values of a given function over ranges of integer values starting from 0.
Produces a four-dimensional collection containing values of a given function over ranges of integer values starting from 0.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3nd dimension
- n4
the number of elements in the 4th dimension
- f
The function computing element values
- returns
A collection consisting of elements
f(i1, i2, i3, i4)
for0 <= i1 < n1
,0 <= i2 < n2
,0 <= i3 < n3
, and0 <= i4 < n4
.
- Definition Classes
- GenTraversableFactory
-
def
tabulate[A](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) ⇒ A): Seq[Seq[Seq[A]]]
Produces a three-dimensional collection containing values of a given function over ranges of integer values starting from 0.
Produces a three-dimensional collection containing values of a given function over ranges of integer values starting from 0.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- n3
the number of elements in the 3nd dimension
- f
The function computing element values
- returns
A collection consisting of elements
f(i1, i2, i3)
for0 <= i1 < n1
,0 <= i2 < n2
, and0 <= i3 < n3
.
- Definition Classes
- GenTraversableFactory
-
def
tabulate[A](n1: Int, n2: Int)(f: (Int, Int) ⇒ A): Seq[Seq[A]]
Produces a two-dimensional collection containing values of a given function over ranges of integer values starting from 0.
Produces a two-dimensional collection containing values of a given function over ranges of integer values starting from 0.
- n1
the number of elements in the 1st dimension
- n2
the number of elements in the 2nd dimension
- f
The function computing element values
- returns
A collection consisting of elements
f(i1, i2)
for0 <= i1 < n1
and0 <= i2 < n2
.
- Definition Classes
- GenTraversableFactory
-
def
tabulate[A](n: Int)(f: (Int) ⇒ A): Seq[A]
Produces a collection containing values of a given function over a range of integer values starting from 0.
Produces a collection containing values of a given function over a range of integer values starting from 0.
- n
The number of elements in the collection
- f
The function computing element values
- returns
A collection consisting of elements
f(0), ..., f(n -1)
- Definition Classes
- GenTraversableFactory
-
def
toString(): String
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.
- returns
a String representation of the object.
- Definition Classes
- AnyRef → Any
-
def
unapplySeq[A](x: Seq[A]): Some[Seq[A]]
This method is called in a pattern match { case Seq(...) => }.
This method is called in a pattern match { case Seq(...) => }.
- x
the selector value
- returns
sequence wrapped in an option, if this is a Seq, otherwise none
- Definition Classes
- SeqFactory
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int
,Float
,Array
orOption
which are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collection
and its sub-packages contain Scala's collections frameworkscala.collection.immutable
- Immutable, sequential data-structures such asVector
,List
,Range
,HashMap
orHashSet
scala.collection.mutable
- Mutable, sequential data-structures such asArrayBuffer
,StringBuilder
,HashMap
orHashSet
scala.collection.concurrent
- Mutable, concurrent data-structures such asTrieMap
scala.collection.parallel.immutable
- Immutable, parallel data-structures such asParVector
,ParRange
,ParHashMap
orParHashSet
scala.collection.parallel.mutable
- Mutable, parallel data-structures such asParArray
,ParHashMap
,ParTrieMap
orParHashSet
scala.concurrent
- Primitives for concurrent programming such asFutures
andPromises
scala.io
- Input and output operationsscala.math
- Basic math functions and additional numeric types likeBigInt
andBigDecimal
scala.sys
- Interaction with other processes and the operating systemscala.util.matching
- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect
- Scala's reflection API (scala-reflect.jar)scala.xml
- XML parsing, manipulation, and serialization (scala-xml.jar)scala.swing
- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)scala.util.parsing
- Parser combinators, including an example implementation of a JSON parser (scala-parser-combinators.jar)Automatic imports
Identifiers in the scala package and the
scala.Predef
object are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
List
is an alias forscala.collection.immutable.List
.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
String
is an alias forjava.lang.String
.