Hah, I apparently decided I needed to speak at 2x speed for folks 😛

I like the speaking style you've got - no 'um's, which I'm guilty of, and very animated

ah cool 🙂

also didn't realise that Datomic used Datalog, like you did, doh!

you have to squint a little, but it's datalog semantics if not its syntax

heh, I was talking to a dev friend about the similarity of react to imgui the other day. I'd been wondering what the more strict functional crowd thought of imgui (in C or elsewhere)...

I really love it, very refreshing way to spit out UI

I think there's actually a more fundamental idea underlying all the immediate mode ideas over the years: at it's core it's really the idea of reducing a domain to a datastructure and then feeding a complete representation of that domain to an interpreter

(both imgui and react that is!) having spent years building Java UIs!

it's a wonderful pattern for lots of problems 🙂

Right .. but my "boiling down" of that key concept sidesteps event logs/sourcing and just sees state--f()-->state

datomic is built on a log I think

Couldn't you make the argument that event logs and CRDTs are just retained mode interfaces for state management? You're applying a series of transformations to a cached representation. The transformations (events/CRDT updates) are the canonical representation.

the main advantage is enabling you to change your mind

argh. .. ok .. go on!

with the log, I can choose an entirely different interpreter (in the information theory sense) and arrive at a valid alternate future

(just thinking that over..) 🙂

one way of looking at it is that if you only store final states, then you're tying the meaning of events/information to your current, likely incomplete, interpretation of those

yeah, but "barring effects that escape into the real world"

nope

hmm ... (skeptical feelings but unfocused as a response) 🙂

the bank example is good because it's not a closed system

yus

banks today generally do what you'd expect: your balance goes negative

I'll need to sleep on it and think about it in the shower tomorrow.. 😄

yeah 🙂

which scares me as Git is a nightmare!

well, it's the principle

basic problem is when you have system A rolled back to prior state/version, and system B has already assimilated the 'wrong' state - its behaviour can't be determined when A is back in time

depends entirely on the way the systems communicate 🙂

off to bed now, it's Wed 2nd here . . g'night!

In the Granger talk there were comments about how industry and academia are coming together. I don't see anything useful for simplicity coming out of academia or the slightest bit of cooperation in terms of practical language development. The brilliant work of Prof N. Wirth of ETH has been dumped onto the ash-heap of history. His stuff was real simple compared to anything else of the time. Academia is busy using R, or playing around with Coq and similar tools which is not a practical tool for general purpose programming. The obsession with proving programs correct is a mostly pointless exercise, as you can't even prove TicTacToe correct using that system, because it doesn't have concept of drawing. Hardly anyone is doing raw computation now, it is 99% about interactive graphics as expressed as websites, IOS/Android Apps, etc. I wish academia was making the next generation of tools for us to use, with their tens of billions in funding that collectively they have each year, but alas i can't think of a useful project originating from academia in a long time. All the action i see is around what Google is doing, or Amazon with AWS, Apple with Swift, or what JetBrains is doing with their now dominant IDE. By my estimates, Academia is using far more closed-source, monthly-subscription software than private companies, tools like ArcGIS, R, Mathematica, Adobe Creative Suite, are all dirt cheap for students, but quite expensive for post-students, and that is the business model, of capturing academics with really nice packaged software that they will end up licensing as they graduate into companies. I see a bizarro world now, where academia is entrenched in commercial tools, and industry is going more open source and doing the R&D at their own expense, and ignoring the academic output for the most part. I think the universities are so fat now, they are like the pentagon; with deans flying around in private jets, pulling 7 figures. And i don't see the serfs known as graduate students empowered to do big enough projects to make a toolchain.

@Duncan Cragg wrote

basic problem is when you have system A rolled back to prior state/version, and system B has already assimilated the 'wrong' state

Can the the idea of managed time be pushed down to the OS? Then all systems built on this OS use the same psuedo time base and cross system consistent state is tractable.

probably .. sounds a bit over the top to me though! 😄

Time control of a client + server program is a fascinating challenge. It can be done, at least to the point of reversing both in sync. It would be wonderful for diagnosing a multiplayer game.

@ibdknox Welcome to the 2x club. Two favorite lines, ""we deal with concurrency through this horrid mess of locks and sadness" and "C is not going to save us."

I think the real reason academia is so heavily using R, ArcGIS and other subscription products is that they aren't sharing code; they instead need to share data using the same program, and their datasets are complex and it is just too painful to have different data structures, so they tend to standardize on a small set of products so it is easy to ship data back and forth. In many fields like Archaeology,. Geology, etc., the main work they do is actually collecting data. Data hoarding is a big problem in archaeology for example, because if you spent hot days using a small brush to delicately expose some ancient thing the last thing you want is some hotshot doing a better job analyzing your hard-won data. And let's not forget that the vast majority of people using computers are not in the computer field. But the real issue i see is that for the purposes of this future of coding group, i don't think we can expect a warm welcome from the academic communities in any field, because they are so already standardized on high quality subscription-based commercial software, with strong support groups already formed. I think the early adopter audience for new languages is going to come from the hobbyist and curious professionals, who have quite a different need set than the other users, but are at least open to something new. So this is why R, MatLab, ArcGIS and many other expensive subscription products dominate the academic space. In the hobbyist environment on the other hand, free tools are very common, and you see Python, Atom, etc.

@wtaysom - interesting. I think we've had a similar conversation before. Do you have any publicly available material about your experiments with managed time?

I wish. Was last working on it seriously in February, and have since come to reject the specifics of that approach, want to try something more Eve-like the next time around. Let me share two tricky bits instead. Start with identity of introduced entities when comparing parallel histories. Suppose the conceptual different between two histories is that in one you added an extra entity somewhere along the way. If, for example, you are tracking them by some index, then all indices will be affected and you're in for trouble. This is essentially the same trouble one encounters with operational transformation of text and even good old textual diff.

Thanks for the insights @wtaysom.