Stepper (original) (raw)
scala.collection.Stepper
See theStepper companion object
Steppers exist to enable creating Java streams over Scala collections, see scala.jdk.StreamConverters. Besides that use case, they allow iterating over collections holding unboxed primitives (e.g., Array[Int]) without boxing the elements.
Steppers have an iterator-like interface with methods hasStep and nextStep(). The difference to iterators - and the reason Stepper is not a subtype of Iterator - is that there are hand-specialized variants of Stepper for Int, Long and Double (IntStepper, etc.). These enable iterating over collections holding unboxed primitives (e.g., Arrays, scala.jdk.Accumulators) without boxing the elements.
The selection of primitive types (Int, Long and Double) matches the hand-specialized variants of Java Streams (java.util.stream.Stream, java.util.stream.IntStream, etc.) and the corresponding Java Spliterators (java.util.Spliterator, java.util.Spliterator.OfInt, etc.).
Steppers can be converted to Scala Iterators, Java Iterators and Java Spliterators. Primitive Steppers are converted to the corresponding primitive Java Iterators and Spliterators.
Type parameters
A
the element type of the Stepper
Attributes
Companion
Source
Graph
Supertypes
Known subtypes
Members list
Returns a set of characteristics of this Stepper and its elements.
Returns an estimate of the number of elements of this Stepper, or Long.MaxValue.
Check if there's an element available.
Check if there's an element available.
Attributes
Source
Return the next element and advance the stepper
Return the next element and advance the stepper
Attributes
Source
Split this stepper, if applicable.
Split this stepper, if applicable. The elements of the current Stepper are split up between the resulting Stepper and the current stepper.
May return null, in which case the current Stepper yields the same elements as before.
See method trySplit in java.util.Spliterator.
Attributes
Source
Returns an Iterator corresponding to this Stepper.
Returns an Iterator corresponding to this Stepper. Note that Iterators corresponding to primitive Steppers box the elements.
Attributes
Source
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