It’s a bit niche for HN, but SwiftUI rendering works way better when following this. In a ForEach, you really shouldn’t have any branching, or you‘ll pay quite catastrophic performance penalties. I found out the hard way when rendering a massive chart with Swift Charts. All branching must be pushed upwards.
Kind of, it’s a declarative framework like React & co. Under the hood it maps to either UIKit components or GPU (Metal) rendering. And view identity is very important for change detection. AFAICT, putting a branch in a ForEach invalidates all elements in that ForEach whenever one branch changes, because its whole identity changes.
So say I have an set of elements to render (A,B,C) but they can can come in any order or number (C,B,A,B). If I want to render in the given order, how would I approach this for the best performance implementation?
Why? Does it interpret the code?