out_stream option to simplify connecting up a Loopback/PipedStream to an external Stream

[embedded-creations]

Hi, I've been making extensive use of your library over the past few months, working on improvements to the Commander Library, creating a new library that connects multiple Streams (including File objects) between two Arduinos over a single Stream object, and adapting tinyproto's error checking and retransmit functionality to act as a Stream. One thing I needed was the ability to buffer Stream data that is eventually going to be sent to another Stream object, so I added support for that to ArduinoBufferedStreams. I added documentation for the new features in the form of examples.

I like to keep commits as small logical blocks, but you should be able to review this PR by looking at the "Files Changed" tab to see all the changes at once instead of individual commits. If you'd prefer I squashed the commits, I can do that, just need to figure out how.

If you don't want to merge this commit or think the merge might take a long time, please let me know so I can figure out what to do instead, as my other projects that I want to release soon depend on my changes in your library.

Your code was a big help to me early on in understanding how Stream objects work and how to convert data to/from Streams, so thanks for that!

[paulo-raca]

Hello!

Thank you for the contribution, I like it a lot! ❤️

However I think these changes modify what a LoopbackStream / PipedStream are designed to do.

Instead, I suggest to add the new functionality in new classes: For example we could add a BufferedStream to implement the LoopbackStream + out_stream you want.

What do you think?

[embedded-creations]

I'm open to that idea. If I understand you correctly, BufferedStream would be derived from LoopbackStream, and add the new out_stream functionality. We'd then need the equivalent for PipedStream, would it be named BufferedPipedStream, and contain two BufferedStream objects?

It seems to me like it's more work to separate the classes and maintain them separately than to add some optional functionality to the existing Loopback and Piped classes. The additional functionality doesn't seem to me to add much overhead to the existing classes.

[embedded-creations]

Hi @paulo-raca, any thoughts on the above?