What is the difference between static and dynamic member lookup?

Swift provides both static and dynamic member lookup for flexible API design.\n\n• **Static Member Lookup:**\n• Resolved at compile time\n• Type-safe and performant\n• Standard Swift behavior\n\n\nstruct Point { \n let x: Double\n let y: Double\n \n let zero = Point(x: 0, y: 0)\n}\n\nlet origin = Point.zero // Static lookup\n\n\n• **Dynamic Member Lookup:**\n• Resolved at runtime\n• Enables flexible APIs\n• Requires @dynamicMemberLookup\n\n\n@dynamicMemberLookup\nstruct DynamicStruct { \n var storage: [String: Any] = [:]\n \n subscript(dynamicMember key: String) -> Any? {\n get { return storage[key] }\n set { storage[key] = newValue }\n }\n}\n\nvar dynamic = DynamicStruct()\ndynamic.name = "Swift" // Dynamic lookup\ndynamic.version = 5.5\n\n\n• **Advanced Dynamic Lookup:**\n\n@dynamicMemberLookup\nstruct JSON { \n let data: [String: Any]\n \n subscript(dynamicMember key: String) -> JSON? {\n let value = data[key] else { return nil }\n let dict = value as? [String: Any] {\n return JSON(data: dict)\n }\n return nil\n }\n}\n\n// Usage\nlet json = JSON(data: ["user": ["name": "Alice", "age": 30]])\nlet userName = json.user?.name // Dynamic chaining\n\n\n• **Use Cases:**\n• JSON/Dictionary wrappers\n• Scripting language bridges\n• Dynamic configuration\n• Builder patterns