SodaFlow.Collections.Core 2.0.0

• .NETFramework 4.7.2

  • SodaFlow.Core (>= 5.0.0 && < 6.0.0)
  • System.Collections.Immutable (>= 8.0.0)
  • System.ValueTuple (>= 4.6.2)

• .NETStandard 2.0

  • SodaFlow.Core (>= 5.0.0 && < 6.0.0)
  • System.Collections.Immutable (>= 8.0.0)
  • System.ValueTuple (>= 4.6.2)

• net6.0

  • SodaFlow.Core (>= 5.0.0 && < 6.0.0)
  • System.Collections.Immutable (>= 8.0.0)
  • System.ValueTuple (>= 4.6.2)

2.0.0

Adds the fold of a collection, which CollectionFoldUtility.FoldImpl gives to each
language surface. A total, a count of a view, or an average had no operation
here, thus each caller wrote the delta of a change by hand. The fold takes a
group: a function that reads the identity and the state of one item, a zero, an
add, and a subtract. Each change carries the states before it and the states
after it, thus the fold removes the previous value of each key that the change
names and adds the new one. The cost of an edit is the count of the keys in that
edit.

CollectionFoldUtility.FoldByIdentityImpl gives the fold of the identities. It
reads only the item changes that add or remove a key, and each reset. A reset
puts a key in Added only when the view did not have it before, thus it does not
name a key that one edit replaced and that stays in the view. The fold reads
each key of a reset for that cause. ItemChange has an internal IsReset for it,
and its constructor takes that value.

A group, and not one combine function, because only an invertible operation can
answer an edit with no read of each item. A sum and a count are groups. A maximum
is not one, and this operation cannot give one.

The first value is a read of the store at the construction, thus a caller gives
no seed. A view folds its own items, because the States of a scoped snapshot hold
the keys of that view alone. A change from a reset names each key of the view,
thus the fold stays correct at a cost of the size of the view for that one
change.

BREAKING: KeyOrder.ByKey(keyComparer) is now ByKey(keyComparer,
isDescending), as each other factory that takes a comparer also names its
direction. Add isDescending: false to keep an existing order, or call
ByKey() where the comparer was Comparer<TKey>.Default. Adds ByKey() and
ByKeyDescending(), with the default comparer.

BREAKING: MappedItems<TResult> is a sealed class, where it was a readonly
struct, as the status of MapAsync is. A struct with a Dispose is a handle that
each copy duplicates, and its default value threw at a disposal. Source that
reads Items and calls Dispose needs no edit. Anything compiled against 1.x
does, because a struct and a class are not the same type to the runtime.
default(MappedItems<T>) is null now. A second Dispose never releases an object
that the first one released.

BREAKING for the two language surfaces: SortByKeyImpl takes the direction, and
FilterByIdentityImpl takes a cell of the predicate in place of the predicate.
A SodaFlow.Collections or SodaFlow.FSharp.Collections built against 1.x does
not run against this; take the 2.x of each with it.

Adds the internal members that the two language surfaces need for ItemCell:
ItemCellImpl and CreateItemCell on ReactiveCollection, and the projection for
one item on an item change and on a view change.

Fixed: the stage of a slice lost an edit to a key that kept its position in
the window. The stage compares the window before a change with the window after
it, and it gave only a ViewUpdate to a key that the comparison found in both. A
ViewMove from a sort above carries a new state, and a replacement arrives as a
ViewRemove and a ViewInsert. The stage now gives a ViewUpdate for the first,
and a ViewRemove and a ViewInsert at the same index for the second.

Requires SodaFlow.Core 5.x, which ships in the same release.

1.0.1

Adds the package icon that nuget.org shows beside this package. No source file
changed since 1.0.0.

Every package here ships this release together, so the dependency versions
move with it.

1.0.0

First release.

Requires SodaFlow.Core 4.0.1 or later, and nothing else from this repository.
4.0.1 is the release that grants this assembly access to the core's internals,
which it reaches throughout; against 4.0.0 it builds from source but throws
MethodAccessException at run time, so the dependency floor is 4.0.1 rather than
4.0.0.

StateMap exposes Pairs as well as Keys, for anything that reads the whole
collection - a total, an average, a count. Iterating Keys and looking up each
one answers the same question and costs an O(log32 n) search per item; on a
hundred thousand items that measured three times slower.

OrderedKeys and StateMap are abstract classes with internal constructors rather
than interfaces, so what a snapshot answers with is closed: one storage strategy and
one filtered face of it, and two kinds of key set. What builds the next version
of either is not on them - that is the protocol between stages, and a version
built by anyone else would be one the collection had never heard of. The Create
overloads that took a state map are gone with it, since nothing outside could
supply one.

IIdentity is the one interface left, and it is the one meant to be implemented:
say an identity carries its own key and Create will take it from there.

There is no optional type in this API. Lookups are TryGetItem, TryGetState and
TryGetNewState, and IndexOf answers -1, so that each language surface can put
its own optional type on top - Maybe in SodaFlow.Collections, option in
SodaFlow.FSharp.Collections - and neither pays for the other's.

---

About this package

The engine behind SodaFlow.Collections and SodaFlow.FSharp.Collections. It
declares the types a consumer holds - Item, CollectionSnapshot,
ItemChange, CollectionEdit, StateMap, OrderedKeys, KeyOrder, CollectionViewChange
and the ViewOperation hierarchy - along with ReactiveCollection itself and the view
chain the language wrappers expose.

Install one of those two rather than this. On its own this package gives you
types whose operations are internal, reached only through the wrappers.

Full notes: https://github.com/MorseCode-Software/SodaFlow/releases