jshholland

It's an insert-mode binding, built in by default.

There is a substantive difference between "couldn't get any users because of an error" (Nothing) and "succeeded but found no users" (Just []).

But, if that really is the reason for Maybe [a] over [a], I'd still prefer Either SomeUsefulErrorType [a].

We have a way to write traditional SFGs as string diagrams and an isomorphism to behaviours which respects the kind of graphical reasoning used in the blog. So you can show that two SFGs are behaviourally equivalent, or, using some more recent work, that all the behaviours of one are also behaviours of another, i.e. inclusion of sets of behaviours. String diagrams are also more general than SFGs, but can still be mapped to behaviours, so you could have an "unimplementable" string diagram to serve as a specification, and use the axiomatisation of inclusion to show that a particular SFG is a valid implementation of that spec.

As for whether anyone outside the research programme is actually doing that, I don't know. But in principle it's a useful formal methods type theory.

I kind of agree with you (especially on "math-lite category theory" being upvoted by people who read it and feel smart for understanding it), but I think the point has slightly been missed. The blog is a sort of side project, a popular treatment of the linear algebra stuff coming out of the "real research", which is applying the string diagrams to find graphical, compositional axiomatisations of concurrent systems. The programme has had some success with signal flow graphs (even making it onto the blog: https://graphicallinearalgebra.net/2016/09/07/31-fibonacci-a... ) and they were starting to look into Petri nets as my study was wrapping up.

(source: I was a postgrad supervised by Pawel)

Not entirely a coincidence - see this paper (coauthored by the guy behind the blog in the OP): https://dl.acm.org/doi/10.1145/3290338

It's not just $5 for an accurate data point; it's $5 to convince yourself that the commitment to the goal is really real. Betting for free is very different to betting for real money.

I also used that keyboard for a short while. Currently, I use 5 Tiles [0]. I can get to 20-30 wpm with it, which is acceptable, though not as fast as a regular keyboard. The killer feature is that it takes up less than 10% of the screen, rather than the ~40% a conventional one would.

Gripes: it's not great for symbol input (you have to remember all sorts of crazy zigzaggy patterns, or pull up a list which defeats the whole point of not taking up half the screen) and auto-capitalisation doesn't really work. But I use it as my regular keyboard and it does the job.

[0]: http://fivetiles.com/

It's probably equivalent to receiving a letter written in green ink (British perception that letters written to media in green ink are more likely to be from what I'll charitably call fringe interestts)

A friend had an idea to make a Twitter client that just drops half of all tweets at random. I don't think he ever got round to implementing it, but I thought it was quite a cool idea.