Hands-On Design Patterns and Best Practices with Julia

Developing the state object

To simulate the growth of an L-System model, we can develop an LState type that keeps track of the current state of the growth. It's a simple type that just keeps a reference to the model, the current iteration of growth, and the current result. For this, consider the following code:

struct LState    model    current_iteration    resultend

The constructor just needs to take the model as the only argument. It defaults current_iteration to 1 and defaults result to the axiom of the model, as shown here:

"Create a L-system state from a `model`."LState(model::LModel) = LState(model, 1, model.axiom)

We need a function to advance to the next stage of the growth. So, we just provide a next function:

function next(state::LState) ...