Shader Nodes Control Flow

Geometry Nodes has recently gotten some nice control flow features:

• Repeat Zone
• Closures (available in daily builds)
• Bundles (available in daily builds)
• Menu Switch

It would open up some amazing possibilities for reusable node groups if these kinds of features were also usable in shader nodes.

I recognize that some of these features may be somewhat more limited than their geometry nodes implementation though. Specifically, repeat zones may have to have a fixed (maximum) length in order to be usable in some (mostly older) graphics APIs.

An example use case is a reusable parallax mapping node group, where you can input the depth map as a closure.