Once more at this. This time after seeing Hexagony.

One problem I have with Befunge (not the one you're thinking of, ha) and other fungeoids is that you have a bunch of static information about a program visible in 2D on screen, but a key piece -- the stack -- is invisible. The question I keep returning to is how one might go about making the stack (or any other run-time state used by the program) visible without just bolting it on on the side. This time around, I got hooked on the following metaphor. Imagine a spaceship that contains some data, sets out on a voyage across an infinite 2D plane, and performs various operations depending on the objects it collides with.

Example 1: The space ship contains a row of boxes. Colliding with a number pushes a box on to the nose, colliding with an operator operates on the 1 or 2 front-most boxes in the front. This is a way to display a stack, but a stack in isolation doesn't seem to scale well to larger programs.

Example 2: The spaceship contains a number. Colliding with the BF-inspired primitives + and - causes the number to be incremented and decremented, respectively. Now build addition out of it. Zooming into a number n shows it to be a loop of n iterations. When the spaceship collides with n it loops through n times, and the number inside it has n added to it. At a high zoom, you see the spaceship loop n times before exiting the "solar system". At a low zoom you see the spaceship exit instantaneously with n added to its value. Now you can imagine a reduce operation as a series of solar systems that the spaceship visits one by one.

Example 3: The spaceship contains a binary heap to insert and delete elements from depending on objects it collides with. Zooming into any single collision reveals the tree structure to be the "space" that a smaller spaceship containing a single number bounces among.

Two properties that seem important from these examples:

• A hierarchical nature where space and spaceship are duals, and zooming in and out causes them to turn into each other.
• Rendering the state of a spaceship needs to be extensible (like in my old Pong demo). We need to leave Befunge's ASCII behind.

At the largest scale, state machines feel like a really powerful way to represent the state within a spaceship. I often find them to be the outermost architecture of a large program. But to actually find the state machine I have to flail around for a long time. If we could use some visual paradigm at the largest scales but zoom into text as needed, programs might be much more comprehensible.

This post is part of my Freewheeling Apps Devlog.

Comments gratefully appreciated. Please send them to me by any method of your choice and I'll include them here.