Generating Custom Data Structures

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Generating Custom Data Structures

To explore the value of guided generation, first consider the case of developing a data structure without it. Run the app and enter the following prompt:

Create a menu for lunch at a casual dining restaurant
Menu created by asking the chat app.
Vupi jsiawem cm ijgakg pra rfil ihp.

import Foundation
import FoundationModels

enum MealType: String {
  case breakfast = "Breakfast"
  case lunch = "Lunch"
  case dinner = "Dinner"
}

struct MenuItem {
  let name: String
  let description: String
  let ingredients: [String]
  let cost: Decimal
}

struct RestaurantMenu {
  let type: MealType
  let menu: [MenuItem]
}

@Generable(description: "A menu of offerings for a restaurant for a single meal.")

@Generable

@Generable(description: "A single dish for a restaurant menu.")

@Generable(description: "A single dish for a restaurant menu.")
struct MenuItem {
  @Guide(description: "Name for this dish.")
  let name: String

  @Guide(description: "The description of this dish in a style appropriate for a restaurant menu.")
  let description: String

  @Guide(description: "The main ingredients for this dish.")
  let ingredients: [String]

  @Guide(description: "A cost for this dish in US dollars, which should be appropriate for the ingredients", )
  let cost: Decimal
}

@Generable(description: "A menu of offerings for a restaurant for a single meal.")
struct RestaurantMenu {
  let type: MealType

  @Guide(description: "A list of menu items, appropriate for the selected type of meal.", .count(4...8))
  let menu: [MenuItem]
}

import SwiftUI
import FoundationModels

struct MenuItemView: View {
  var menuItem: MenuItem

  var body: some View {
      HStack {
        Text(menuItem.name)
        Spacer()
        Text(menuItem.cost, format: .currency(code: "USD"))
      }
      .font(.title)
    Text(menuItem.description)
      .frame(maxWidth: .infinity, alignment: .leading)
      .padding(.leading, 15.0)
      .font(.headline)
    Text(menuItem.ingredients.joined(separator: " • "))
      .font(.subheadline)
  }
}

#Preview {
  let item = MenuItem(
    name: "Caesar Salad",
    description: "Romaine lettuce tossed in Caesar dressing with parmesan cheese and croutons.",
    ingredients: ["romaine lettuce", "Caesar dressing", "parmesan cheese", "croutons"],
    cost: 10.0
  )
  MenuItemView(menuItem: item)
}

@State var menu: RestaurantMenu?

// 1
func generateLunchMenu() async {
  // 2
  let session = LanguageModelSession(instructions: "You are a helpful model assisting with generating realistic restaurant menus.")
  // 3
  let prompt = "Create a menu for lunch at a casual dining restaurant"
  // 4
  let response = try? await session.respond(to: prompt, generating: RestaurantMenu.self)
  // 5
  menu = response?.content
}

Task {
  await generateLunchMenu()
}

if let menu = menu {
  ScrollView {
    ForEach(menu.menu, id: \.name) { item in
      MenuItemView(menuItem: item)
      Divider()
    }
  }
}
Complete generated menu.
Sosydegi sopaheqad fevi.
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