object Iterator
The Iterator object provides various functions for creating specialized iterators.
- Source
- Iterator.scala
- Version
2.8
- Since
2.8
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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
-
implicit
def
IteratorCanBuildFrom[A]: BufferedCanBuildFrom[A, Iterator]
With the advent of
TraversableOnceandIterator, it can be useful to have a builder which operates onIterators so they can be treated uniformly along with the collections.With the advent of
TraversableOnceandIterator, it can be useful to have a builder which operates onIterators so they can be treated uniformly along with the collections. Seescala.util.Random.shufflefor an example. -
def
apply[A](elems: A*): Iterator[A]
Creates an iterator with given elements.
Creates an iterator with given elements.
- elems
The elements returned one-by-one from the iterator
- returns
An iterator which produces the given elements on the first calls to
next, and which has no further elements.
-
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 aClassCastExceptionat 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
ClassCastExceptionif the receiver object is not an instance of the erasure of typeT0.
-
def
clone(): AnyRef
Create a copy of the receiver object.
-
def
continually[A](elem: ⇒ A): Iterator[A]
Creates an infinite-length iterator returning the results of evaluating an expression.
Creates an infinite-length iterator returning the results of evaluating an expression. The expression is recomputed for every element.
- elem
the element computation.
- returns
the iterator containing an infinite number of results of evaluating
elem.
-
val
empty: Iterator[Nothing]
The iterator which produces no values.
-
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: Any): Boolean
The equality method for reference types.
-
def
fill[A](len: Int)(elem: ⇒ A): Iterator[A]
Creates iterator that produces the results of some element computation a number of times.
Creates iterator that produces the results of some element computation a number of times.
- len
the number of elements returned by the iterator.
- elem
the element computation
- returns
An iterator that produces the results of
nevaluations ofelem.
-
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. -
def
from(start: Int, step: Int): Iterator[Int]
Creates an infinite-length iterator returning values equally spaced apart.
Creates an infinite-length iterator returning values equally spaced apart.
- start
the start value of the iterator
- step
the increment between successive values
- returns
the iterator producing the infinite sequence of values
start, start + 1 * step, start + 2 * step, ...
-
def
from(start: Int): Iterator[Int]
Creates an infinite-length iterator which returns successive values from some start value.
Creates an infinite-length iterator which returns successive values from some start value.
- start
the start value of the iterator
- returns
the iterator producing the infinite sequence of values
start, start + 1, start + 2, ...
-
final
def
getClass(): Class[_]
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 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
trueif the receiver object is an instance of erasure of typeT0;falseotherwise.
- Definition Classes
- Any
-
def
iterate[T](start: T)(f: (T) ⇒ T): Iterator[T]
Creates an infinite iterator that repeatedly applies a given function to the previous result.
Creates an infinite iterator that repeatedly applies a given function to the previous result.
- start
the start value of the iterator
- f
the function that's repeatedly applied
- returns
the iterator producing the infinite sequence of values
start, f(start), f(f(start)), ...
-
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
-
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(start: Int, end: Int, step: Int): Iterator[Int]
An iterator producing equally spaced values in some integer interval.
An iterator producing equally spaced values in some integer interval.
- start
the start value of the iterator
- end
the end value of the iterator (the first value NOT returned)
- step
the increment value of the iterator (must be positive or negative)
- returns
the iterator producing values
start, start + step, ...up to, but excludingend
-
def
range(start: Int, end: Int): Iterator[Int]
Creates nn iterator returning successive values in some integer interval.
Creates nn iterator returning successive values in some integer interval.
- start
the start value of the iterator
- end
the end value of the iterator (the first value NOT returned)
- returns
the iterator producing values
start, start + 1, ..., end - 1
-
def
single[A](elem: A): Iterator[A]
Creates an iterator which produces a single element.
Creates an iterator which produces a single element. Note: Equivalent, but more efficient than Iterator(elem)
- elem
the element
- returns
An iterator which produces
elemon the first call tonext, and which has no further elements.
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
tabulate[A](end: Int)(f: (Int) ⇒ A): Iterator[A]
Creates an iterator producing the values of a given function over a range of integer values starting from 0.
Creates an iterator producing the values of a given function over a range of integer values starting from 0.
- end
The number of elements returned by the iterator
- f
The function computing element values
- returns
An iterator that produces the values
f(0), ..., f(n -1).
-
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
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
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.collection.parallel.immutable- Immutable, parallel data-structures such asParVector,ParRange,ParHashMaporParHashSetscala.collection.parallel.mutable- Mutable, parallel data-structures such asParArray,ParHashMap,ParTrieMaporParHashSetscala.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.swing- A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)scala.util.parsing- Parser combinators (scala-parser-combinators.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.