Class CollectionSnapshot<TKey, TIdentity, TState>

Namespace

SodaFlow.Collections

Assembly

SodaFlow.Core.Collections.dll

A collection at one version: the identity map, which changes only at a structural edit, and the state map. A view reads them through its own scope.

[PublicAPI]
public sealed class CollectionSnapshot<TKey, TIdentity, TState> where TKey : notnull where TIdentity : notnull

Type Parameters

TKey

The type of the keys.

TIdentity

The type of the immutable part of an item.

TState

The type of the mutable part of an item.

Inheritance

object

CollectionSnapshot<TKey, TIdentity, TState>

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Extension Methods

CollectionExtensionMethods.Lookup<TKey, TIdentity, TState>(CollectionSnapshot<TKey, TIdentity, TState>, TKey)

MaybeExtensionMethods.ToMaybe<T>(T?)

UnitExtensionMethods.Ignore<T>(T)

UnitExtensionMethods.Upcast<T>(T)

Remarks

The snapshot of the root is the full store. The snapshot of a view is the same two maps behind a set of keys that the view holds. Thus, a stage costs one small object for each change and copies nothing, and a key that the view does not hold is missing from it. Count counts the view, ContainsKey(TKey) answers for the view, and a lookup of a key out of the view finds nothing. For that cause there is no path from a view to the store below it. The scope is the snapshot, and it is not a wrapper that a caller can remove.

Properties

Count

The number of items.

Identities

The immutable part of each item. This code replaces this object only at a structural edit, thus a test of the two references is a correct test for a change of the shape.

States

The mutable part of each item.

Methods

ContainsKey(TKey)

True when this snapshot has a key.

TryGetItem(TKey, out Item<TIdentity, TState>?)

Returns the two parts of the item for a key, when there is one.