[donaldihunter]

Visual languages often fail when it comes to concurrent development where the state of the art is textual diff and merge. The IBM Rational suite attempted visual model diff/merge but I recall it being unworkable in practice.

Modern collaborative visual tools like Miro sidestep the concurrent development problem by being live multiplayer and by essentially having no version management at all.

Most visual BPM tools that I'm aware of try to mix flowchart style programming with e.g. Javascript on activity nodes, but they fail provide any developer-time syntax checking or completion. They also tend to serialise to XML which is unworkable in practice for diff/merge of the visual logic.

In a previous job we developed an in-house flowchart based language that embedded Javascript. We put the effort into writing a first-class Eclipse plugin that had syntax checking and completion across all graphical and Javascript constructs. It even had interactive debugging that interleaved graphical and textual single-stepping. We never solved the diff/merge problem in a satisfactory way.

[james_ross]

for a long time I've believed that the way to bridge the visual and the textual worlds is to generate the visuals from a plain text source of truth. I've never gone so far as to make a visually editable programming language, but I have done multiple projects where, for example, process diagrams in an IDEF0 style were generated from human readable text propositions of the form:

Prepare Meal is a Process Oven enables Prepare Meal Utensils enable Prepare Meal Prepare Meal transforms Raw Ingredients Prepare Meal produces Finished Meal Menu governs Prepare Meal Customer Order governs Prepare Meal

You can map out a business process using a very simple (and XML-free, and diffable) plain text DSL and generate interactive diagrams from it. My most recent example is for concept maps along similar lines.