I think the difficulty here is addressing: who is your target audience? Depending on that answer, you have different existing relatively succesful visual programming languages. For example, game designers have managed to make good use of Unreals' blueprints to great effect. Hobbists use Comfy UIs node language to wire up generative AI components to great effect. As far as generic computing goes, Scratch has managed to teach a lot of programming principles to people looking to learn. The problem comes in when you try and target a generic systems programmer: the target is too abstract to be able to create an effective visual language. In this article, they try and solve this issue by choosing specific subproblems which a visual representation is helpful: codebase visualization, computer network topology, memory layouts, etc...but none of them are programming languages
[post author] I agree. On many domains you can find a great mapping between some visual representation and how the developer (beginner or not) wants to think about the problem.
I personally don't see any one pictorial representation that maps to a general programming language. But if someone does find one, in the large and in the small, that'd be great!
Not even all textual languages map well to every problem space.
Blueprints are a good callout(and Kismet before them). Many PLCs[1] are heavily visual language based with Ladder, FBD or other variants. I wouldn't be surprised if they were the most widely used application of visual programming languages.
> I personally don't see any one pictorial representation that maps to a general programming language.
I agree. What I've had in mind for a while now is very different from this.
What I envision is "text" in the sense that it's not a diagram, but more advanced textual representation. Over hundreds of years mathematicians have evolved a concise, unambiguous, symbolic notation for formulae, yet programmers are still using tools that are backward compatible with dot matrix terminals from the 60's: simple characters used to write lines in files.
Blocks, conditions, iteration, exits (return, exception, etc.,) pipelines, assignment, type and other common concepts could be represented symbolically. The interface would still be text-like, but the textual representation would be similar to mathematical notation, where the basic constructs of code are depicted as common, well understood, dynamically drawn symbols that programmers deeply inculcate.
Key properties include extreme concision and clarity of the "instruction pointer." Concision is crucial to reduce the cognitive cost of large amounts of logic. The latter is a thing that is entirely obscured in most visual programming schemes and also absent from conventional mathematical notation: the location of the current instruction is absolutely crucial to understanding logic.
I wish I had more time to elaborate what I have in mind, much less actually work on it.
Scratch is the only type of visual programming I've enjoyed using. It's easy to read if you're an experienced programmer because it has the same structure as regular code, and it's easy to read for beginners because everything is broken into large blocks that have what they do written right on them. The way code is structured in most programming languages is actually very logical and intuitive, and it's the most successful system we have so far. The problem for beginners is that they can't figure out if they enjoy programming until they've learned the syntax, which can be very discouraging for some people. I've seen Scratch bridge that gap for people a couple of times, and I think it's probably the best model when it comes to teaching people to code.
I think other types of models would only be useful for situations where writing code isn't the most intuitive way to make something. From my limited experience, a visual system for making shaders is a pretty good idea, because ideally, you don't want to have many conditional branches or loops, but you might have a lot of expressions that would look ugly in regular code.
