zlacker

>> you need a hierarchical organization, functions calling functions calling functions. How do you represent that graphically?

Not saying graphical programming is a good idea, but the basic abstraction mechanism is to define new boxes, which you can look inside by opening (like some VHDL modeling tools do). Even in SICP it is said it is a bad idea and do not escalate. But is clear that the primitive is “the box” the means of combination, the lines between boxes, and mean of abstraction is making new boxes.

I thin the real problem is that there is exactly 1 primitive, one mean of abstraction, and one of combination, and that seems to not be enough.

>>f1shy+(OP)
What else could you have? Whatever you are building, you will always have some primitives and ways of combining them and that's practically it. To make things more manageable, you start abstracting, give names to things and refer to them by name instead of by their structure. The next level up would probably by parameterization, instead of having a name for a thing you have a name plus parameters for a family of things. Maybe before that you could get a bit more fancy with instantiation, allow things like repetition. But that again is pretty much it, make parameterized instantiation a bit more fancy and you will quickly create a Turing complete meta layer capable of generating arbitrary constructs in the layer we started with.