Renaming to do or consider

• change ISeries.Date to Timestamp to avoid conflict with .NET reserved name
• change Quote to Bar or Candle to allow future path to consuming bid/ask quotes with proper nomenclature. Confirm potential use of Tick as individual trade information.
• change BasicData to QuotePart since we're using this in new contexts for streaming
• Streaming classes as “EmaHub”. These are really hubs that are both observers and obervables

Related migration documentation

• Ensure maximum backwards compatibility
  • [Obsolete] IQuote as base to IBar
  • with Timestamp => Date (or some form of graceful transition)
• update documentation, migration notes, [Obsolete] transitions, where possible

Additional testing to do, or to consider

• add comprehensive manual test project to v2, to exercise all public interfaces; but, also to identify all breaking changes to ensure max use of [Obsolete] transitions and complete migration documentation.
  • use this as base for Observer.Streaming project (in v3 branch)
  • similarly update missing public use cases to Tests.Other project

Documentation to do, or to consider for previews

• add temporary dotnet.stockindicators.dev/v3 DNS pointer
  • and related NuGet release notes URL
  • and related deployer URL, that's used in draft release notes generator

Interface designs to do, or to consider

• consider switching to IReadOnlyList or IList as external list interfaces, instead of IEnumerable, but double-check consequences. I kind of think converting to list happens more often than not with end use; not sure of pros/cons.
• ensure primary public classes can be mocked (has interface or is otherwise virtual). There's likely a conflict with sealed results; however, output classes don't typically need to be mocked with end-user testing (verify).

For consideration; but may want to implement this in a v3.1

• add external data cache scenarios to EMA/SMA, to proof wider implementation in future add standalone buffer-style increment methods #1091, for both I/O (see note)
  • IQuote cache
  • IResult or IReusable
  • test scenarios

    /// <summary>
    /// Optional.  Use externally provided cache.
    /// </summary>
    /// <param name="externalCache"></param>
    /// <remarks>
    /// Allow users to provide their own cache storage location.
    /// </remarks>
    protected AbstractCache(
        List<TSeries> externalCache)
    {
        Cache = externalCache;
        throw new NotImplementedException();
    }

• restore .NET Standard v2.1, if possible

@thomasd3 (re: #1245), as a quick forecast, I’m hoping to get this major version out by end of this year in the next 2-3 months. I was aiming to time it with the .NET 9 release date, but don’t think that’s going to happen.

I’ll also publish an updated preview edition soon; we’re still working through concepts and bigger breaking changes.

• Consider Cysharp/ObservableCollections

Very excited about this major update @DaveSkender - really cool stuff.

This probably doesn't fit into your library anywhere but I am writing a system that uses FusionCache to store candles, it's extremely fast and versatile, worth checking out.

• consider ZiggyCreatures/FusionCache