Goofing around with Box

App/Utilities/Box.swift

@@ -0,0 +1,50 @@
+//
+//  Box.swift
+//  Box
+//
+//  Created by James Magahern on 7/13/21.
+//
+
+import UIKit
+
+struct Box<Identifier: Hashable> {
+    typealias Compartment = (Identifier, CGRect)
+    typealias Realized = (Identifier, UIView)
+    
+    @resultBuilder
+    struct BoxBuilder {
+        static func buildEither(first component: [Compartment]) -> Compartment {
+            component[0]
+        }
+        
+        static func buildEither(second component: [Compartment]) -> Compartment {
+            component[0]
+        }
+        
+        static func buildBlock(_ compartments: Compartment...) -> [Compartment] {
+            return compartments
+        }
+    }
+    
+    public var boundingRect: CGRect {
+        get {
+            compartmentMap.reduce(into: CGRect.zero) { (result, compartment) in
+                result = result.union(compartment.value)
+            }
+        }
+    }
+    
+    private var compartmentMap: [Identifier: CGRect] = [:]
+    
+    init(@BoxBuilder _ compartments: () -> [Compartment]) {
+        self.compartmentMap = compartments().reduce(into: [:]) { (result, compartment) in
+            result[compartment.0] = compartment.1
+        }
+    }
+    
+    public func fill(_ realized: [Identifier: UIView]) {
+        realized.forEach { (key, value) in
+            value.frame = compartmentMap[key] ?? .zero
+        }
+    }
+}