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Show HN: Octopus – a directed acyclic graph for app development

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Show HN: Octopus – a directed acyclic graph for app development

#1

Post by bbsimonbb »

Directed acyclic graphs are muched discussed in comp-sci, but octopus appears to be the first reusable, turnkey, ready-to-wear, off-the-shelf implementation of a DAG for application development, in any language, that I'm aware of.

This is remarkable because DAGs hit a sweet spot in the middle of the three common programming paradigms (OO, event-driven, functional). Let's have a DAG as the top-level structure of our applications. Data-fetching and onChange handlers live in DAG nodes, next to the data they act on. The UI flows out from the DAG with fine-grained reactivity. Our app state is effortlessly consistent, because any outside change (user action, api result) unleashes a graph traversal. Our UI components become much simpler, because they just need to dumbly reflect values in the graph.

I'm putting this up for a second time. Absolutely no-one bit the first time, which can't be right :-)

Show HN: Octopus – a directed acyclic graph for app development
github.com

Re: Show HN: Octopus – a directed acyclic graph for app development

#2

Post by kitd »

> Directed acyclic graphs are muched discussed in comp-sci, but octopus appears to be the first reusable, turnkey, ready-to-wear, off-the-shelf implementation of a DAG for application development, in any language, that I'm aware of.

I may be misunderstanding what this is, but back in the J2EE days ISTR Struts having something very similar to this, ie a flow from page to page declared apart from the actual page logic itself. Edit: and all done in XML, so obviously doesn't count!

Cool project though!

Re: Show HN: Octopus – a directed acyclic graph for app development

#5

Post by efnx »

> Directed acyclic graphs are muched discussed in comp-sci, but octopus appears to be the first reusable, turnkey, ready-to-wear, off-the-shelf implementation of a DAG for application development, in any language, that I'm aware of.

I wrote one for Rust called moongraph: https://crates.io/crates/moongraph https://github.com/schell/moongraph

It powers my configurable renderer and my ECS. I'm sure lots of other folks have written their own and they might not even know it's a DAG.

Re: Show HN: Octopus – a directed acyclic graph for app development

#6

Post by archibaldJ »

I don’t really understand what values such design pattern can bring worth (that will outweigh its own complexities)

my experience working with DAGs programmatically (ie not as an abstraction (like in React) but actually handling the edges&nodes of a graph-based abstraction in code) is that it looks nice theoretically but in practice top-down (conceptual) approach like this often tends to over-complicate things

would love to see some real-world examples where an actual dev team, etc, find values in graph-theortical-based abstractions like this

Re: Show HN: Octopus – a directed acyclic graph for app development

#7

Post by kokanee »

How is React state not a DAG out of the box? What problems does this solve? The pitch appears to be:

> any outside change (user action, api result) unleashes a graph traversal. Our UI components become much simpler, because they just need to dumbly reflect values in the graph.

But that sounds the same as the reasoning behind React's one-way data flow.

Re: Show HN: Octopus – a directed acyclic graph for app development

#8

Post by 082349872349872 »

kitd wrote: post #2

> Directed acyclic graphs are muched discussed in comp-sci, but octopus appears to be the first reusable, turnkey, ready-to-wear, off-the-shelf implementation of a DAG for application development, in any language, that I'm aware of. I may be misunderstanding what this is, but back in the J2EE days ISTR Struts having something very similar to this, ie a flow from page to page declared apart from the actual page logic…

it's tempting to write a sh(1) based webapp that uses make(1) under the hood to provide similar functionality...

Re: Show HN: Octopus – a directed acyclic graph for app development

#9

Post by hobofan »

Almost every modern framework is implicitly modeled as a DAG? It just rarely used that nomenclature. Heck with Elm a whole language exists for that principle.

I'm really not sure what's supposed to be different here. As is evident from the repository you obviously know about React and Vue, so maybe try to contrast it to them, or how it fits in in relation to them? To me it looks like you are building a system-in-a-system, where you are rebuilding the primitives that already come with React (or any of its peers).

Re: Show HN: Octopus – a directed acyclic graph for app development

#10

Post by catapart »

Like others are saying: I think a lot of modern frameworks already fit this mold, or are so close that people can't quite tell the difference. But for a near 1-1 example, maybe look at XState? Especially given that XState has a visual, graph view which interactively indicates state in real time.
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