Trait scala.collection.IterableOnce
Companion object IterableOnce
trait IterableOnce[+A] extends Any
Abstract Value Members
abstract def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
- Definition Classes
- Any
abstract def iterator: Iterator[A]
Concrete Value Members
final def !=(arg0: Any): Boolean
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- Any
final def ##(): Int
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
.
- returns
a hash value consistent with ==
- Definition Classes
- Any
def +(other: String): String
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toany2stringadd[IterableOnce[A]] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
def ->[B](y: B): (IterableOnce[A], B)
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toArrowAssoc[IterableOnce[A]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
final def ==(arg0: Any): Boolean
Test two objects for equality. The expression x == that
is equivalent to if (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
- Any
final def asInstanceOf[T0]: 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.
- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
def ensuring(cond: (IterableOnce[A]) => Boolean, msg: => Any): IterableOnce[A]
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toEnsuring[IterableOnce[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: (IterableOnce[A]) => Boolean): IterableOnce[A]
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toEnsuring[IterableOnce[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean, msg: => Any): IterableOnce[A]
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toEnsuring[IterableOnce[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean): IterableOnce[A]
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toEnsuring[IterableOnce[A]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def equals(arg0: Any): Boolean
Compares the receiver object (this
) with the argument object (that
) for equivalence.
Any implementation of this method should be an equivalence relation:
-
It is reflexive: for any instance
x
of type Any
, x.equals(x)
should return true
.It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and only if y.equals(x)
returns true
.It is transitive: for any instances x
, y
, and z
of type Any
if x.equals(y)
returns true
and y.equals(z)
returns true
, then x.equals(z)
should return true
. If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is usually necessary to override hashCode
to ensure that objects which are "equal" (o1.equals(o2)
returns true
) hash to the same scala.Int. (o1.hashCode.equals(o2.hashCode)
).
- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- Any
def formatted(fmtstr: String): String
Returns string formatted according to given format
string. Format strings are as for String.format
(@see java.lang.String.format).
- Implicit
- This member is added by an implicit conversion from IterableOnce[A] toStringFormat[IterableOnce[A]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
def hashCode(): Int
Calculate a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
. However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals
method.
- returns
the hash code value for this object.
- Definition Classes
- Any
final def isInstanceOf[T0]: Boolean
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.
- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
def knownSize: Int
- returns
The number of elements in this collection, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.
def stepper[S <: Stepper[_]](implicit shape: StepperShape[A, S]): S
Returns a Stepper for the elements of this collection.
The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.
The implicit StepperShape parameter defines the resulting Stepper type according to the element type of this collection.
-
For collections of
Int
, Short
, Byte
or Char
, an IntStepper is returnedFor collections of Double
or Float
, a DoubleStepper is returnedFor collections of Long
a LongStepper is returnedFor any other element type, an AnyStepper is returnedNote that this method is overridden in subclasses and the return type is refined to S with EfficientSplit
, for example IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.
def toString(): String
Returns a string representation of the object.
The default representation is platform dependent.
- returns
a string representation of the object.
- Definition Classes
- Any
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/collection/IterableOnce.html
A template trait for collections which can be traversed either once only or one or more times.
Note:
IterableOnce
does not extend IterableOnceOps. This is different than the general design of the collections library, which uses the following pattern:The goal is to provide a minimal interface without any sequential operations. This allows third-party extension like Scala parallel collections to integrate at the level of IterableOnce without inheriting unwanted implementations.