kotlin.Iterator.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2015 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package kotlin.collections
/**
* An iterator over a collection or another entity that can be represented as a sequence of elements.
* Allows to sequentially access the elements.
*/
public interface Iterator {
/**
* Returns the next element in the iteration.
*/
public operator fun next(): T
/**
* Returns `true` if the iteration has more elements.
*/
public operator fun hasNext(): Boolean
}
/**
* An iterator over a mutable collection. Provides the ability to remove elements while iterating.
* @see MutableCollection.iterator
*/
public interface MutableIterator : Iterator {
/**
* Removes from the underlying collection the last element returned by this iterator.
*/
public fun remove(): Unit
}
/**
* An iterator over a collection that supports indexed access.
* @see List.listIterator
*/
public interface ListIterator : Iterator {
// Query Operations
override fun next(): T
override fun hasNext(): Boolean
/**
* Returns `true` if there are elements in the iteration before the current element.
*/
public fun hasPrevious(): Boolean
/**
* Returns the previous element in the iteration and moves the cursor position backwards.
*/
public fun previous(): T
/**
* Returns the index of the element that would be returned by a subsequent call to [next].
*/
public fun nextIndex(): Int
/**
* Returns the index of the element that would be returned by a subsequent call to [previous].
*/
public fun previousIndex(): Int
}
/**
* An iterator over a mutable collection that supports indexed access. Provides the ability
* to add, modify and remove elements while iterating.
*/
public interface MutableListIterator : ListIterator, MutableIterator {
// Query Operations
override fun next(): T
override fun hasNext(): Boolean
// Modification Operations
override fun remove(): Unit
/**
* Replaces the last element returned by [next] or [previous] with the specified element [element].
*/
public fun set(element: T): Unit
/**
* Adds the specified element [element] into the underlying collection immediately before the element that would be
* returned by [next], if any, and after the element that would be returned by [previous], if any.
* (If the collection contains no elements, the new element becomes the sole element in the collection.)
* The new element is inserted before the implicit cursor: a subsequent call to [next] would be unaffected,
* and a subsequent call to [previous] would return the new element. (This call increases by one the value \
* that would be returned by a call to [nextIndex] or [previousIndex].)
*/
public fun add(element: T): Unit
}