Interesting concept! It does remind me of the observables somewhat, where nodes are functions, which accept data coming in from events, which it transforms, and then chooses to emit new values or not.
This flips that, so nodes are data, which accept functions from events, it applies that function to itself, then decides to propagate that event onwards or not.
I like it! That model works really well for this sort of visual programming demoed in the infinite canvas stuff.
I only glanced at the article, but it also reminds me of Dataflow programming, incrementally updated materialized views, etc. (all the same concept at the end of the day, and yes, very similar to observables)
Some of the videos are broken for me (using Firefox). Otherwise looks pretty neat.
Compared to FRP it is perhaps a bit more declarative in the definition of scopes, but otherwise seems equivalent. I'm interested in more details on this. I'm also a bit confused by
> This model has not yet been formalised, and while the propagators themselves can be simply expressed as a function ... I have not yet found an appropriate way to express scopes and the relationship between the two.
This seems straightforward to me (e.g. a scope could be a set of types, where each distinct event has a distinct type) so I think I'm missing something here.
All but two of the videos are broken for me on both Chrome and Firefox. I would love to see the rest!
I encourage people to read the original Propagator Networks paper by Alexey Radul (advisor: Prof. Gerald Sussman of SICP) referenced in the Prior Work section. It's full of fascinating ideas.
I think tools like these, with better UX and more guard rails for the code, can really help people understand logic and systems in a much more visually intuitive way. In some aspects, these propagators work similar to Excel, which I think a lot of people already have some intuition for.
As written, a "scope" is a function, s: G² → None + T, from the current global state and the previous global state to an optional value of some type T. Meanwhile, a "propagator" is a function, p: G² × A × B → B, from the current global state, the previous global state, a source node, and a target node to a new target node, such that p(g, g', a, b) = if s(g, g') is None then b else f(s(g, g'), a, b) for some f: T × A × B → B.
For example tick(g, g') = time(g') - time(g), and change(g, g') = if node_s(g') ≠ node_s(g) then () else None where node_s(g) gets the source node of the change scope from global state g.
In practice the outputs of a scope can be computed once per state change and called an event, rather than computed on demand each time it's used, and scopes which return None don't need to be propagated. Also, I suspect it would be useful to restrict scopes to (A × B)² → None + T or even just A² → None + T, so that events are limited to propagating along chains of edges.
Wow! That's neat! There are a lot to explore beyond interactive objects.
One of the first thing that comes to mind was is about Smalltalk, and the idea that it is about the messages and not the objects.
The next thing to come in mind is about how this allows for composition of interactions. I think it can enable highly local customization that can still receive software updates from upstream. I am thinking about how one of the problems with extensible specifications (such as XMPP) eventually lead to an ecosystem where feature updates cannot propogate easily; and we might see something like that in the Fediverse
What is separating this concept from dataflow programming, perhaps with slightly different semantics and interaction patterns? (I reckon my understanding might be limited so I'm genuinely seeking enlightenment)
This kind of node/edge based programming model is one I've been interested to see applied to LLMs.
In some sense, we can see the input of an LLM as a node, the LLM itself as a function describing the edge of the graph, and the output of the LLM as a new node.
This feels very similar to how database table triggers work. You define trigger conditions, and then the trigger on table A tells table B how to update itself. The tables store only data.
Could be a meaningful bridge between “nocode” and code, avoiding what seems like a common pain point of eventual nocode limitations. I know there are other solutions in this space, but yours is very nicely done.
Please continue work on this, and yell out if you need collaborators.
graypegg|1 year ago
This flips that, so nodes are data, which accept functions from events, it applies that function to itself, then decides to propagate that event onwards or not.
I like it! That model works really well for this sort of visual programming demoed in the infinite canvas stuff.
chatmasta|1 year ago
CyberDildonics|1 year ago
noelwelsh|1 year ago
Compared to FRP it is perhaps a bit more declarative in the definition of scopes, but otherwise seems equivalent. I'm interested in more details on this. I'm also a bit confused by
> This model has not yet been formalised, and while the propagators themselves can be simply expressed as a function ... I have not yet found an appropriate way to express scopes and the relationship between the two.
This seems straightforward to me (e.g. a scope could be a set of types, where each distinct event has a distinct type) so I think I'm missing something here.
aag|1 year ago
I encourage people to read the original Propagator Networks paper by Alexey Radul (advisor: Prof. Gerald Sussman of SICP) referenced in the Prior Work section. It's full of fascinating ideas.
https://dspace.mit.edu/handle/1721.1/54635
davexunit|1 year ago
FRP systems are typically limited to acyclic graphs. The system in this article allows for cycles.
low_tech_punk|1 year ago
https://youtu.be/HB5TrK7A4pI?si=99cUwmS_03VwLUP7&t=2038
blixt|1 year ago
A game of cat and mouse: https://x.com/blixt/status/1797384954172625302
An analog clock: https://x.com/blixt/status/1798393279194824952
I think tools like these, with better UX and more guard rails for the code, can really help people understand logic and systems in a much more visually intuitive way. In some aspects, these propagators work similar to Excel, which I think a lot of people already have some intuition for.
GrantMoyer|1 year ago
For example tick(g, g') = time(g') - time(g), and change(g, g') = if node_s(g') ≠ node_s(g) then () else None where node_s(g) gets the source node of the change scope from global state g.
In practice the outputs of a scope can be computed once per state change and called an event, rather than computed on demand each time it's used, and scopes which return None don't need to be propagated. Also, I suspect it would be useful to restrict scopes to (A × B)² → None + T or even just A² → None + T, so that events are limited to propagating along chains of edges.
hosh|1 year ago
One of the first thing that comes to mind was is about Smalltalk, and the idea that it is about the messages and not the objects.
The next thing to come in mind is about how this allows for composition of interactions. I think it can enable highly local customization that can still receive software updates from upstream. I am thinking about how one of the problems with extensible specifications (such as XMPP) eventually lead to an ecosystem where feature updates cannot propogate easily; and we might see something like that in the Fediverse
omneity|1 year ago
zoogeny|1 year ago
In some sense, we can see the input of an LLM as a node, the LLM itself as a function describing the edge of the graph, and the output of the LLM as a new node.
donpark|1 year ago
https://github.com/OrionReed/scoped-propagators
https://github.com/dennishansen/holograph
jiggawatts|1 year ago
fiddlerwoaroof|1 year ago
MurrayHurps|1 year ago
Could be a meaningful bridge between “nocode” and code, avoiding what seems like a common pain point of eventual nocode limitations. I know there are other solutions in this space, but yours is very nicely done.
Please continue work on this, and yell out if you need collaborators.