Large PRs

[jpfairbanks]

We had the huge abstraction PR (#541) that was a lot of work. This is a place for people to comment on how to avoid such giant PRs in the future.

The PR grew because there were a few changes that needed to happen at the same time.

• Abstraction of the interface
  This was always going to take a lot of lines but most of the changes would have been simple changes to the type constraints on function signatures.

• JLv0.6 compatibility
  This would have some complex changes for things like channels, constructor syntax.
  It would also require waiting for PRs on dependencies.

• Testing and Documentation Improvements.
  These are mostly additions and thus easy to approve.
  The switch to test sets meant that a lot of lines would get touched but only whitespace would be affected.

• Benchmarking
  Introducing benchmarks was also mostly additional lines.

Conclusion

I think the changes that were introduced in the big PR were actually 4 separate PRs put together.
The problem is that they needed to be scheduled to reduce conflicts. Once we had an open PR that diverged far enough from master there was no choice but to lump them all together. So we needed to do 0.6 compatibility; then abstraction; and then benchmarking, testing, and documenting in parallel. Each PR would be squashed before merging and each commit on master would be a working version of the code.

[sbromberger]

One issue that I ran into is that it made sense to update the docs as I went through the abstraction. There were tons of errors in the docs, and we changed a bunch of stuff with traits, and it all needed notes.

I suppose I could've kept two copies of the repo - one for abstraction work, and one for docs - but that seems like a recipe for merge conflict disaster.

[sbromberger]

Benchmarks were actually introduced in #538, so any changes to benchmark/ were to support 0.6 or abstractions.

[sbromberger]

I think this is just a conversation between you and me at this point, @jpfairbanks , so I'll close it out but feel free to reopen/comment/whatever.