OrderedScatterSet

Artifact: androidx.collection:collection

Kotlin |Java

public sealed class OrderedScatterSet<E extends Object>

Known direct subclasses

MutableOrderedScatterSet

MutableOrderedScatterSet

MutableOrderedScatterSet is a container with a MutableSet-like interface based on a flat hash table implementation that preserves the insertion order for iteration.

OrderedScatterSet is a container with a Set-like interface based on a flat hash table implementation that preserves the insertion order for iteration. The underlying implementation is designed to avoid all allocations on insertion, removal, retrieval, and iteration. Allocations may still happen on insertion when the underlying storage needs to grow to accommodate newly added elements to the set.

This implementation guarantees the order of the elements when iterating over them using forEach or the iterator provided by asSet.

Though OrderedScatterSet offers a read-only interface, it is always backed by a MutableOrderedScatterSet. Read operations alone are thread-safe. However, any mutations done through the backing MutableScatterSet while reading on another thread are not safe and the developer must protect the set from such changes during read operations.

Note: when a Set is absolutely necessary, you can use the method asSet to create a thin wrapper around an OrderedScatterSet. Please refer to asSet for more details and caveats.

See also
`MutableOrderedScatterSet`

Summary

Protected constructors
`<E extends Object> OrderedScatterSet()`

Public methods
`final boolean`	`all(@NonNull Function1<@NonNull element, @NonNull Boolean> predicate)` Returns true if all elements match the given `predicate`.
`final boolean`	`any()` Returns `true` if this set has at least one element.
`final boolean`	`any(@NonNull Function1<@NonNull element, @NonNull Boolean> predicate)` Returns true if at least one element matches the given `predicate`.
`final @NonNull Set<@NonNull E>`	`asSet()` Wraps this `OrderedScatterSet` with a `Set` interface.
`final boolean`	`contains(@NonNull E element)` Returns true if the specified `element` is present in this hash set, false otherwise.
`final @IntRange(from = 0) int`	`count()` Returns the number of elements in this set.
`final @IntRange(from = 0) int`	`count(@NonNull Function1<@NonNull element, @NonNull Boolean> predicate)` Returns the number of elements matching the given `predicate`.The order in which the predicate is called over the elements is arbitrary.
`boolean`	`equals(Object other)` Compares the specified object `other` with this hash set for equality.
`final @NonNull E`	`first()` Returns the first element in the collection.
`final @NonNull E`	`first(@NonNull Function1<@NonNull element, @NonNull Boolean> predicate)` Returns the first element in insertion order in the collection for which `predicate` returns `true`.
`final E`	`firstOrNull( @NonNull Function1<@NonNull element, @NonNull Boolean> predicate )` Returns the first element in insertion order in the collection for which `predicate` returns `true` or `null` if there are no elements that match `predicate`.
`final void`	`forEach(@NonNull Function1<@NonNull element, Unit> block)` Iterates over every element stored in this set by invoking the specified `block` lambda.
`final void`	`forEachReverse(@NonNull Function1<@NonNull element, Unit> block)` Iterates over every element stored in this set by invoking the specified `block` lambda.
`final @IntRange(from = 0) int`	`getCapacity()` Returns the number of elements that can be stored in this set without requiring internal storage reallocation.
`final @IntRange(from = 0) int`	`getSize()` Returns the number of elements in this set.
`int`	`hashCode()` Returns the hash code value for this set.
`final boolean`	`isEmpty()` Indicates whether this set is empty.
`final boolean`	`isNotEmpty()` Returns `true` if this set is not empty.
`final @NonNull String`	`joinToString( @NonNull CharSequence separator, @NonNull CharSequence prefix, @NonNull CharSequence postfix, int limit, @NonNull CharSequence truncated, Function1<@NonNull E, @NonNull CharSequence> transform )` Creates a String from the elements separated by `separator` and using `prefix` before and `postfix` after, if supplied.
`final @NonNull E`	`last()` Returns the last element in the collection.
`final @NonNull E`	`last(@NonNull Function1<@NonNull element, @NonNull Boolean> predicate)` Returns the last element in insertion order in the collection for which `predicate` returns `true`.
`final E`	`lastOrNull(@NonNull Function1<@NonNull element, @NonNull Boolean> predicate)` Returns the first element in insertion order in the collection for which `predicate` returns `true` or `null` if there are no elements that match `predicate`.
`final boolean`	`none()` Returns `true` if this set has no elements.
`final @NonNull List<@NonNull E>`	`toList()` Returns a new list containing this set's entries, in insertion order.
`@NonNull String`	`toString()` Returns a string representation of this set.

Protected constructors