Show HN: Visual flow-based programming for Erlang, inspired by Node-RED

Are there other similar projects that you're familiar with? Perhaps targeting other languages?

What are the major problems with this approach to programming? Are large programs hard to work with?

Main problems with visual flow based programming is the tooling: there aren't any good tools for doing visual comparison nor visual version control. Things like GitHub aren't able to render flow code as seen in the editor.

For Node-RED that means that the Json that defines a flow can be compared but that soon becomes meaningless because semantic changes get mixed with visual changes, i.e., that the x,y coordinates of a node have changed - is meaningless for the logic of the code.

This means that code sharing and collaborative development is difficult purely visually but only because tooling is missing. Compared to textual programming before things like SourceForge or Git and we had the same issues as we do with visual coding now.

Node-RED has a bunch of features to make large programs maintainable. Things like link nodes that allow jumping between flows also allow code reuse. There also subflows which encapsulate repeated code and can be referenced from anywhere.

That's also why I chose Node-RED for this because it seems to be the most mature and best maintained low-code visual flow-based programming tool. There are others such as n8n (which seems to be the other biggie) but they lack the generalness of Node-RED. I can create web sites with Node-RED while and the same time controlling my LEDs via Raspberry installation. Node-RED is extremely flexible.

[1]: https://github.com/mdkrieg/py-red

How stable are node and edge IDs and their ordering? Could you sort the JSON before saving so the output is more stable and diff-able?

Another thought is, how would you code up a flow like this in your preferred language if you were just writing code in that language (you didn't care about the visual editting). Call most of the same functions, but do it directly. Ok, think about that, then write a transformation from the NODE language to output source in your preferred language.

I have some sense that coding this type of control flow logic doesn't work well with text line based diffs because of the complexity of the problem, less the syntax.

Jsons are definitely diff-able but it's the difference between a change that changes the logic of the flow or a change that is purely visual and has no affect on the logic of the flow that is hard to distinguish by just diffing the JSONs.

Remember the Json contains location of nodes and labels of nodes as well as logic of nodes - if a label of a node changes it doesn't affect the flow logic or how it works.

So if the value of an 'x' changed, that means the node moved along the x-axis. Did the value of 'func' (function value for a function node) change, then that is a logically change. Now what change is important if you only looking at the JSON. So you need to remember that 'x' and 'y' are visual, 'func', 'tmpl', 'rules' are logical. And what is important for each node isn't the same across all possible nodes ...

> this type of control flow logic doesn't work well with text line

Exactly that's why places like GitHub would need a lot work to support visual coding in proper way. Diffs would have to become like image comparisons that line-by-line diffs.

And that is partly why visual coding has taken off - the tooling isn't available.