kotlin.collections.Iterators.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of kotlin-compiler-embeddable Show documentation

the Kotlin compiler embeddable

There is a newer version: 2.1.0-Beta1

Show newest version

@file:kotlin.jvm.JvmMultifileClass
@file:kotlin.jvm.JvmName("CollectionsKt")

package kotlin.collections

/**
 * Creates an [Iterator] for an [Enumeration], allowing to use it in `for` loops.
 */
@kotlin.jvm.JvmVersion
public operator fun  java.util.Enumeration.iterator(): Iterator = object : Iterator {
    override fun hasNext(): Boolean = hasMoreElements()

    public override fun next(): T = nextElement()
}

/**
 * Returns the given iterator itself. This allows to use an instance of iterator in a `for` loop.
 */
@kotlin.internal.InlineOnly
public inline operator fun  Iterator.iterator(): Iterator = this

/**
 * Returns an [Iterator] wrapping each value produced by this [Iterator] with the [IndexedValue],
 * containing value and it's index.
 */
public fun  Iterator.withIndex(): Iterator> = IndexingIterator(this)

/**
 * Performs the given [operation] on each element of this [Iterator].
 */
public inline fun  Iterator.forEach(operation: (T) -> Unit) : Unit {
    for (element in this) operation(element)
}

/**
 * Iterator transforming original `iterator` into iterator of [IndexedValue], counting index from zero.
 */
internal class IndexingIterator(private val iterator: Iterator) : Iterator> {
    private var index = 0
    final override fun hasNext(): Boolean = iterator.hasNext()
    final override fun next(): IndexedValue = IndexedValue(index++, iterator.next())
}