Simplifying Session Management in CIDER

The CIDER 2.0 announcement was, by necessity, a mile wide and an inch deep - there was simply too much to cover. So I’m planning to make up for that with a small series of articles, each shedding a bit more light on one notable change and the reasoning behind it. This is the first one, and it tackles the area that has probably generated more confusion (and bug reports) than any other over the years: session management. Truth be told, I meant to write this article back when the work landed in CIDER 1.22,1 but I was so busy wrapping up CIDER 2.0 that I’m only getting to it now, as part of this series. Better late than never, right? A bit of history Back in the pre-history of CIDER (before 0.18), there were no sessions at all - just connections, and a very simple rule: commands went to the most recently used connection that made sense for your buffer. Crude? Sure. But it mostly worked OK, and - crucially - everyone understood it. CIDER 0.18 replaced this with Sesman-based session…