object Seq extends Delegate[Seq]
This object provides a set of operations to create immutable.Seq values.
- Annotations
- @SerialVersionUID()
- Source
- Seq.scala
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- By Inheritance
- Seq
- Delegate
- SeqFactory
- IterableFactory
- Serializable
- AnyRef
- Any
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- Public
- Protected
Value Members
- final def !=(arg0: Any): Boolean
Test two objects for inequality.
Test two objects for inequality.
- returns
trueif !(this == that), false otherwise.
- Definition Classes
- AnyRef → Any
- final def ##: Int
Equivalent to
x.hashCodeexcept for boxed numeric types andnull.Equivalent to
x.hashCodeexcept 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. Fornullreturns a hashcode wherenull.hashCodethrows aNullPointerException.- returns
a hash value consistent with ==
- Definition Classes
- AnyRef → Any
- final def ==(arg0: Any): Boolean
The expression
x == thatis equivalent toif (x eq null) that eq null else x.equals(that).The expression
x == thatis equivalent toif (x eq null) that eq null else x.equals(that).- returns
trueif the receiver object is equivalent to the argument;falseotherwise.
- Definition Classes
- AnyRef → Any
- def apply[A](elems: A*): Seq[A]
Creates a immutable sequence with the specified elements.
Creates a immutable sequence with the specified elements.
- A
the type of the immutable sequence's elements
- elems
the elements of the created immutable sequence
- returns
a new immutable sequence with elements
elems
- Definition Classes
- Delegate → IterableFactory
- final def asInstanceOf[T0]: T0
Forces the compiler to treat the receiver object as having type
T0, even though doing so may violate type safety.Forces the compiler to treat the receiver object as having type
T0, even though doing so may violate type safety.This method is useful when you believe you have type information the compiler doesn't, and it also isn't possible to check the type at runtime. In such situations, skipping type safety is the only option.
It is platform dependent whether
asInstanceOfhas any effect at runtime. It might do a runtime type test on the erasure ofT0, insert a conversion (such as boxing/unboxing), fill in a default value, or do nothing at all.In particular,
asInstanceOfis not a type test. It does **not** mean:this match { case x: T0 => x case _ => throw ClassCastException("...")
Use pattern matching or isInstanceOf for type testing instead.
Situations where
asInstanceOfis useful:- when flow analysis fails to deduce
T0automatically - when down-casting a type parameter or an abstract type member (which cannot be checked at runtime due to type erasure) If there is any doubt and you are able to type test instead, you should do so.
Be careful of using
asInstanceOfwhenT0is a primitive type. WhenT0is primitive,asInstanceOfmay insert a conversion instead of a type test. If your intent is to convert, use atoTmethod (x.toChar,x.toByte, etc.).- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastExceptionif the receiver is not an instance of the erasure ofT0, if that can be checked on this platform
- when flow analysis fails to deduce
- def clone(): AnyRef
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the
clonemethod is platform dependent.- returns
a copy of the receiver object.
- def concat[A](xss: collection.Iterable[A]*): Seq[A]
Concatenates all argument collections into a single immutable sequence.
Concatenates all argument collections into a single immutable sequence.
- xss
the collections that are to be concatenated.
- returns
the concatenation of all the collections.
- Definition Classes
- IterableFactory
- def empty[A]: Seq[A]
An empty collection
An empty collection
- A
the type of the immutable sequence's elements
- Definition Classes
- Delegate → IterableFactory
- 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
eqmethod implements an equivalence relation on non-null instances ofAnyRef, and has three additional properties:- It is consistent: for any non-null instances
xandyof typeAnyRef, multiple invocations ofx.eq(y)consistently returnstrueor consistently returnsfalse. - For any non-null instance
xof typeAnyRef,x.eq(null)andnull.eq(x)returnsfalse. null.eq(null)returnstrue.
When overriding the
equalsorhashCodemethods, 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
trueif the argument is a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
- It is consistent: for any non-null instances
- def equals(arg0: AnyRef): 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 immutable sequence containing the results of some element computation a number of times.
Produces a five-dimensional immutable sequence 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 3rd 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 immutable sequence that contains the results of
n1 x n2 x n3 x n4 x n5evaluations ofelem.
- Definition Classes
- IterableFactory
- def fill[A](n1: Int, n2: Int, n3: Int, n4: Int)(elem: => A): Seq[Seq[Seq[Seq[A]]]]
Produces a four-dimensional immutable sequence containing the results of some element computation a number of times.
Produces a four-dimensional immutable sequence 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 3rd dimension
- n4
the number of elements in the 4th dimension
- elem
the element computation
- returns
A immutable sequence that contains the results of
n1 x n2 x n3 x n4evaluations ofelem.
- Definition Classes
- IterableFactory
- def fill[A](n1: Int, n2: Int, n3: Int)(elem: => A): Seq[Seq[Seq[A]]]
Produces a three-dimensional immutable sequence containing the results of some element computation a number of times.
Produces a three-dimensional immutable sequence 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 3rd dimension
- elem
the element computation
- returns
A immutable sequence that contains the results of
n1 x n2 x n3evaluations ofelem.
- Definition Classes
- IterableFactory
- def fill[A](n1: Int, n2: Int)(elem: => A): Seq[Seq[A]]
Produces a two-dimensional immutable sequence containing the results of some element computation a number of times.
Produces a two-dimensional immutable sequence 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 immutable sequence that contains the results of
n1 x n2evaluations ofelem.
- Definition Classes
- IterableFactory
- def fill[A](n: Int)(elem: => A): Seq[A]
Produces a immutable sequence containing the results of some element computation a number of times.
Produces a immutable sequence containing the results of some element computation a number of times.
- n
the number of elements contained in the immutable sequence.
- elem
the element computation
- returns
A immutable sequence that contains the results of
nevaluations ofelem.
- Definition Classes
- IterableFactory
- 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
finalizemethod is invoked, as well as the interaction betweenfinalizeand non-local returns and exceptions, are all platform dependent.- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable])
- Note
not specified by SLS as a member of AnyRef
- def from[E](it: IterableOnce[E]): Seq[E]
Creates a target immutable sequence from an existing source collection
Creates a target immutable sequence from an existing source collection
- returns
a new immutable sequence with the elements of
source
- Definition Classes
- Seq → Delegate → IterableFactory
- final def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- def hashCode(): Int
The hashCode method for reference types.
- final def isInstanceOf[T0]: Boolean
Test whether the dynamic type of the receiver object has the same erasure as
T0.Test whether the dynamic type of the receiver object has the same erasure as
T0.Depending on what
T0is, the test is done in one of the below ways:T0is a non-parameterized class type, e.g.BigDecimal: this method returnstrueif the value of the receiver object is aBigDecimalor a subtype ofBigDecimal.T0is a parameterized class type, e.g.List[Int]: this method returnstrueif the value of the receiver object is someList[X]for anyX. For example,List(1, 2, 3).isInstanceOf[List[String]]will return true.T0is some singleton typex.typeor literalx: this method returnsthis.eq(x). For example,x.isInstanceOf[1]is equivalent tox.eq(1)T0is an intersectionX with YorX & Y: this method is equivalent tox.isInstanceOf[X] && x.isInstanceOf[Y]T0is a unionX | Y: this method is equivalent tox.isInstanceOf[X] || x.isInstanceOf[Y]T0is a type parameter or an abstract type member: this method is equivalent toisInstanceOf[U]whereUisT0's upper bound,AnyifT0is unbounded. For example,x.isInstanceOf[A]whereAis an unbounded type parameter will return true for any value ofx.
This is exactly equivalent to the type pattern
_: T0- returns
trueif the receiver object is an instance of erasure of typeT0;falseotherwise.
- Definition Classes
- Any
- Note
due to the unexpectedness of
List(1, 2, 3).isInstanceOf[List[String]]returning true andx.isInstanceOf[A]whereAis a type parameter or abstract member returning true, these forms issue a warning.
- implicit def iterableFactory[A]: Factory[A, Seq[A]]
- Definition Classes
- IterableFactory
- def iterate[A](start: A, len: Int)(f: (A) => A): Seq[A]
Produces a immutable sequence containing repeated applications of a function to a start value.
Produces a immutable sequence containing repeated applications of a function to a start value.
- start
the start value of the immutable sequence
- len
the number of elements contained in the immutable sequence
- f
the function that's repeatedly applied
- returns
a immutable sequence with
lenvalues in the sequencestart, f(start), f(f(start)), ...
- Definition Classes
- IterableFactory
- final def ne(arg0: AnyRef): Boolean
Equivalent to
!(this eq that).Equivalent to
!(this eq that).- returns
trueif the argument is not a reference to the receiver object;falseotherwise.
- Definition Classes
- AnyRef
- def newBuilder[A]: Builder[A, Seq[A]]
- A
the type of the immutable sequence’s elements
- returns
A builder for
immutable.Seqobjects.
- Definition Classes
- Delegate → IterableFactory
- 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
- Annotations
- @native()
- 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
- Annotations
- @native()
- Note
not specified by SLS as a member of AnyRef
- def range[A](start: A, end: A, step: A)(implicit arg0: Integral[A]): Seq[A]
Produces a immutable sequence containing equally spaced values in some integer interval.
Produces a immutable sequence containing equally spaced values in some integer interval.
- start
the start value of the immutable sequence
- end
the end value of the immutable sequence (the first value NOT contained)
- step
the difference between successive elements of the immutable sequence (must be positive or negative)
- returns
a immutable sequence with values
start, start + step, ...up to, but excludingend
- Definition Classes
- IterableFactory
- def range[A](start: A, end: A)(implicit arg0: Integral[A]): Seq[A]
Produces a immutable sequence containing a sequence of increasing of integers.
Produces a immutable sequence containing a sequence of increasing of integers.
- start
the first element of the immutable sequence
- end
the end value of the immutable sequence (the first value NOT contained)
- returns
a immutable sequence with values
start, start + 1, ..., end - 1
- Definition Classes
- IterableFactory
- final def synchronized[T0](arg0: => T0): T0
Executes the code in
bodywith an exclusive lock onthis.Executes the code in
bodywith an exclusive lock onthis.- returns
the result of
body
- 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 immutable sequence containing values of a given function over ranges of integer values starting from 0.
Produces a five-dimensional immutable sequence 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 3rd 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 immutable sequence 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
- IterableFactory
- 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 immutable sequence containing values of a given function over ranges of integer values starting from 0.
Produces a four-dimensional immutable sequence 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 3rd dimension
- n4
the number of elements in the 4th dimension
- f
The function computing element values
- returns
A immutable sequence consisting of elements
f(i1, i2, i3, i4)for0 <= i1 < n1,0 <= i2 < n2,0 <= i3 < n3, and0 <= i4 < n4.
- Definition Classes
- IterableFactory
- def tabulate[A](n1: Int, n2: Int, n3: Int)(f: (Int, Int, Int) => A): Seq[Seq[Seq[A]]]
Produces a three-dimensional immutable sequence containing values of a given function over ranges of integer values starting from 0.
Produces a three-dimensional immutable sequence 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 3rd dimension
- f
The function computing element values
- returns
A immutable sequence consisting of elements
f(i1, i2, i3)for0 <= i1 < n1,0 <= i2 < n2, and0 <= i3 < n3.
- Definition Classes
- IterableFactory
- def tabulate[A](n1: Int, n2: Int)(f: (Int, Int) => A): Seq[Seq[A]]
Produces a two-dimensional immutable sequence containing values of a given function over ranges of integer values starting from 0.
Produces a two-dimensional immutable sequence 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 immutable sequence consisting of elements
f(i1, i2)for0 <= i1 < n1and0 <= i2 < n2.
- Definition Classes
- IterableFactory
- def tabulate[A](n: Int)(f: (Int) => A): Seq[A]
Produces a immutable sequence containing values of a given function over a range of integer values starting from 0.
Produces a immutable sequence containing values of a given function over a range of integer values starting from 0.
- n
The number of elements in the immutable sequence
- f
The function computing element values
- returns
A immutable sequence consisting of elements
f(0), ..., f(n -1)
- Definition Classes
- IterableFactory
- 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
- final def unapplySeq[A](x: Seq[A]): UnapplySeqWrapper[A]
- Definition Classes
- SeqFactory
- def unfold[A, S](init: S)(f: (S) => Option[(A, S)]): Seq[A]
Produces a immutable sequence that uses a function
fto produce elements of typeAand update an internal state of typeS.Produces a immutable sequence that uses a function
fto produce elements of typeAand update an internal state of typeS.- A
Type of the elements
- S
Type of the internal state
- init
State initial value
- f
Computes the next element (or returns
Noneto signal the end of the collection)- returns
a immutable sequence that produces elements using
funtilfreturnsNone
- Definition Classes
- IterableFactory
- final def wait(): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- Note
not specified by SLS as a member of AnyRef
- final def wait(arg0: Long, arg1: Int): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- Note
not specified by SLS as a member of AnyRef
- final def wait(arg0: Long): Unit
See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.
This is the documentation for the Scala standard library.
Package structure
The scala package contains core types like
Int,Float,ArrayorOptionwhich are accessible in all Scala compilation units without explicit qualification or imports.Notable packages include:
scala.collectionand its sub-packages contain Scala's collections frameworkscala.collection.immutable- Immutable, sequential data-structures such asVector,List,Range,HashMaporHashSetscala.collection.mutable- Mutable, sequential data-structures such asArrayBuffer,StringBuilder,HashMaporHashSetscala.collection.concurrent- Mutable, concurrent data-structures such asTrieMapscala.concurrent- Primitives for concurrent programming such asFuturesandPromisesscala.io- Input and output operationsscala.math- Basic math functions and additional numeric types likeBigIntandBigDecimalscala.sys- Interaction with other processes and the operating systemscala.util.matching- Regular expressionsOther packages exist. See the complete list on the right.
Additional parts of the standard library are shipped as separate libraries. These include:
scala.reflect- Scala's reflection API (scala-reflect.jar)scala.xml- XML parsing, manipulation, and serialization (scala-xml.jar)scala.collection.parallel- Parallel collections (scala-parallel-collections.jar)scala.util.parsing- Parser combinators (scala-parser-combinators.jar)scala.swing- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)Automatic imports
Identifiers in the scala package and the
scala.Predefobject are always in scope by default.Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example,
Listis an alias forscala.collection.immutable.List.Other aliases refer to classes provided by the underlying platform. For example, on the JVM,
Stringis an alias forjava.lang.String.