Compukters Core/kotlin.ranges/CharProgression

CharProgression

open class CharProgression(val first: Char, endInclusive: Char, val step: Int) : Iterable<Char> (source)

An ordered progression of Char values with a nonzero, signed step.

Positive steps move upwards; negative steps move downwards. The inclusive last is adjusted to align with first and step, so it may differ from endInclusive. A progression is empty when its bounds run against the step direction. Characters are traversed by UTF-16 code unit, not by Unicode code point.

Parameters

first

the starting value.

endInclusive

the requested inclusive bound in the direction of traversal.

step

the signed difference between successive elements.

Throws

IllegalArgumentException

if step is zero or Int.MIN_VALUE.

Inheritors

Constructors

CharProgression

constructor(first: Char, endInclusive: Char, step: Int)

creates a progression with an aligned final element.

Properties

val first: Char

The starting value; an empty progression does not yield it.

The inclusive final element of a nonempty progression, aligned with first and step.

The signed difference between successive elements; positive for ascending traversal.

Functions

inline fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean

Returns true when every element matches predicate.

inline fun <T> Iterable<T>.any(predicate: (T) -> Boolean): Boolean

Returns true when at least one element matches predicate.

fun <T> Iterable<T>.asSequence(): Sequence<T>

Borrows this iterable as a lazy sequence without traversing or copying it. Each traversal requests a new source iterator; later mutations and invalidation follow the iterable's own contract. Wrappers and iterators use ordinary managed heap quotas.

operator fun <T> Iterable<T>.contains(element: T): Boolean

Checks whether this iterable has an element equal to element.

inline fun <T> Iterable<T>.filter(predicate: (T) -> Boolean): List<T>

Returns a list containing elements matching predicate, in their original iteration order.

fun <T : Any> Iterable<T?>.filterNotNull(): List<T>

Returns a list of non-null elements in their original iteration order.

inline fun <T, C : MutableCollection<in T>> Iterable<T>.filterTo(destination: C, predicate: (T) -> Boolean): C

Appends matching elements to destination in iteration order.

inline fun <T> Iterable<T>.find(predicate: (T) -> Boolean): T?

Returns the first matching element, or null when no element matches predicate.

fun <T> Iterable<T>.first(): T

Returns the first element, throwing NoSuchElementException when empty.

inline fun <T> Iterable<T>.first(predicate: (T) -> Boolean): T

Returns the first matching element, throwing NoSuchElementException when no element matches.

fun <T> Iterable<T>.firstOrNull(): T?

Returns the first element, or null when this iterable is empty.

inline fun <T> Iterable<T>.firstOrNull(predicate: (T) -> Boolean): T?

Returns the first matching element, or null when no element matches predicate.

inline fun <T, R> Iterable<T>.fold(initial: R, operation: (R, T) -> R): R

Accumulates elements in iteration order.

inline fun <T> Iterable<T>.forEach(action: (T) -> Unit)

Calls action for each element in iteration order.

inline fun <T> Iterable<T>.forEachIndexed(action: (Int, T) -> Unit)

Calls action for each element and its zero-based index in iteration order.

fun <T> Iterable<T>.indexOf(element: T): Int

Returns the index of the first equal element, or -1 when no element matches.

open fun isEmpty(): Boolean

Returns whether this progression contains no elements.

open operator override fun iterator(): Iterator<Char>

Creates an independent iterator over this progression in step order.

fun <T> Iterable<T>.lastIndexOf(element: T): Int

Returns the index of the last equal element, or -1 when no element matches.

fun <T> Iterable<T>.lastOrNull(): T?

Returns the last element, or null when this iterable is empty.

inline fun <T> Iterable<T>.lastOrNull(predicate: (T) -> Boolean): T?

Returns the last matching element after traversing this iterable in iteration order.

inline fun <T, R> Iterable<T>.map(transform: (T) -> R): List<R>

Returns a list containing transform applied once to each element in iteration order.

inline fun <T, R : Any> Iterable<T>.mapNotNull(transform: (T) -> R?): List<R>

Applies transform once per element in iteration order and retains only non-null results.

inline fun <T, R : Any, C : MutableCollection<in R>> Iterable<T>.mapNotNullTo(destination: C, transform: (T) -> R?): C

Appends non-null transformed elements to destination in iteration order.

inline fun <T, R, C : MutableCollection<in R>> Iterable<T>.mapTo(destination: C, transform: (T) -> R): C

Appends transformed elements to destination in iteration order.

inline fun <T> Iterable<T>.none(predicate: (T) -> Boolean): Boolean

Returns true when no element matches predicate.

infix fun CharProgression.step(step: Int): CharProgression

Creates a progression with the same direction and a new positive step magnitude.