3 ms·

I feel like you’re weaselling out of your earlier statement a bit. In your top comment you talk about it being hard to look up symbols. I point out that you nee

I feel like you’re weaselling out of your earlier statement a bit. In your top comment you talk about it being hard to look up symbols. I point out that you need to look up symbols for circuit diagrams and you say that actually one doesn’t need to look them up because they are actually intuitive and you invent a new criterion for diagrams to fail so that circuit diagrams can pass through but UML cannot. I claim that circuit diagram symbols aren’t particularly intuitive (e.g. the symbol for a resistor is just a longer wire? The symbol for a transistor is very non-obvious, I think. The symbol for a potentiometer is pretty difficult even if you know how one works.) And another example of a visual representation that works well even though it is for something intangible is the kind of grammar diagram you can see in the SQLite documentation where terminal symbols are in rounded rectangles, non-terminal symbols in regular rectangles, and arrows indicate concatenation (I.e. production rules). To be clear, I don’t want to disagree with your overall opinion that UML is bad or that the symbols are intuitive, and perhaps that is the reason that UML failed, but I think the reasoning about visual notations and the reasons they fail in general is faulty and I don’t think the answer is to find ever narrower definitions of the cases where visual notation systems don’t work.

lisper 4y ago
Fair points all. A few nits though: the symbol for a resistor is not "just a longer wire", it's a zig-zag shape, and IMHO the symbol for a potentiometer is pretty intuitive. And yes, SQL's syntax diagrams work well. But I think the reason they work well is that they aren't trying to describe software, they are trying to describe (the structure of) a certain kind of text and text is spatial. Electric circuit notation could probably be improved. Same for math notation. But both of these are pretty deeply entrenched at this point. (I will note, however, that I am currently working on maintaining a chip design tool that describes circuits using S-expressions so the situation is not hopeless. :-)
- rini17 4y ago
  How do you bridge the gap between trees (s-exprs) and graphs with cycles (actual circuits)?
  - lisper 4y ago
    By using names and references to those names. In the circuit modeling language I am working on the nodes in the graphs are components and the connections between them are signals. Both are first-class entities. They all get assigned unique names which end up being fairly complicated but which you hardly ever have to refer to directly because you are almost always dealing with them at some level of abstract hierarchy where there is a simple name by which they can be referred and the rest of the true global name is implied. This allows you produce a complete description of a chip, i.e. a graph with billions of nodes, using text that is orders of magnitude smaller. And as a bonus you can automatically compile that text down to a physical layout that allows you to actually fabricate the chip. There are graphical representations for the layout as well. But the text is primary.

lisper 4y ago

Fair points all. A few nits though: the symbol for a resistor is not "just a longer wire", it's a zig-zag shape, and IMHO the symbol for a potentiometer is pretty intuitive. And yes, SQL's syntax diagrams work well. But I think the reason they work well is that they aren't trying to describe software, they are trying to describe (the structure of) a certain kind of text and text is spatial. Electric circuit notation could probably be improved. Same for math notation. But both of these are pretty deeply entrenched at this point. (I will note, however, that I am currently working on maintaining a chip design tool that describes circuits using S-expressions so the situation is not hopeless. :-)

rini17 4y ago
How do you bridge the gap between trees (s-exprs) and graphs with cycles (actual circuits)?
- lisper 4y ago
  By using names and references to those names. In the circuit modeling language I am working on the nodes in the graphs are components and the connections between them are signals. Both are first-class entities. They all get assigned unique names which end up being fairly complicated but which you hardly ever have to refer to directly because you are almost always dealing with them at some level of abstract hierarchy where there is a simple name by which they can be referred and the rest of the true global name is implied. This allows you produce a complete description of a chip, i.e. a graph with billions of nodes, using text that is orders of magnitude smaller. And as a bonus you can automatically compile that text down to a physical layout that allows you to actually fabricate the chip. There are graphical representations for the layout as well. But the text is primary.