Add the Getting Started tutorial

docs/tutorials/1-getting-started.md

@@ -1,7 +1,207 @@
-Goal: show the power of auto-derivation
+# Getting started
+Let's start our adventure with jsoniter-scala from parsing and serialization of some complex data structure of nested 
+collections and case classes.
 
-Example: 
-1. 
-Nested case classes with a couple of collections (`Seq` and `Map`)
+## Prerequisites
+In all tutorials we will use [scala-cli](https://scala-cli.virtuslab.org) for running Scala scripts, so you'll need to install it upfront.
 
-Challenge: find concrete (non-abstract) collection from standard Scala library that is not supported yet by auto-derivation
+You can use any text editor to copy and paste provided code snippets. Please, also, check Scala CLI Cookbooks 
+documentation if you use [VSCode](https://scala-cli.virtuslab.org/docs/cookbooks/ide/vscode), [Intellij IDEA](https://scala-cli.virtuslab.org/docs/cookbooks/ide/intellij), or [emacs](https://scala-cli.virtuslab.org/docs/cookbooks/ide/emacs) editors.
+
+Support of Scala CLI by IDEs is improving over time, so that [IntelliJ IDEA](https://www.jetbrains.com/idea/) with the latest version of Scala 
+plugin you can try its [improved support for Scala CLI projects](https://blog.jetbrains.com/scala/2024/11/13/intellij-scala-plugin-2024-3-is-out/#scala-cli).
+
+Latest versions of jsoniter-scala libraries require JDK 11 or above. You can use any of its distributions.
+
+In all tutorials we will start from a file with the following dependencies and imports:
+
+```scala
+//> using scala 3
+//> using dep "com.github.plokhotnyuk.jsoniter-scala::jsoniter-scala-core::2.31.3"
+//> using compileOnly.dep "com.github.plokhotnyuk.jsoniter-scala::jsoniter-scala-macros::2.31.3"
+
+import com.github.plokhotnyuk.jsoniter_scala.core._
+import com.github.plokhotnyuk.jsoniter_scala.macros._
+```
+
+Please just copy and paste code snippets from the subsequent steps and run by pressing some `Run` button/keystroke in 
+your IDE or run it using `scala-cli <file_name>` command from the terminal.
+
+Make sure to preserve indentation when copying and pasting because we will use indenting syntax of Scala 3.
+
+## Definition of a complex data structure
+
+Let's imagine that we need to generate a JSON representation of some report for a US shop.
+
+Below is a definition of its data structures and instantiation of some sample data: 
+
+```scala
+enum Category extends Enum[Category]:
+  case Electronics, Fashion, HomeGoods
+
+case class Product(id: Long, name: String, category: Category, price: BigDecimal, description: String)
+
+enum OrderStatus extends Enum[OrderStatus]:
+  case Pending, Shipped, Delivered, Cancelled
+
+case class OrderItem(product: Product, quantity: Int)
+
+case class Order(id: Long, customer: Customer, items: List[OrderItem], status: OrderStatus)
+
+case class Customer(id: Long, name: String, email: String, address: Address)
+
+case class Address(street: String, city: String, state: String, zip: String)
+
+enum PaymentType extends Enum[PaymentType]:
+  case CreditCard, PayPal
+
+case class PaymentMethod(`type`: PaymentType, details: Map[String, String]/*e.g. card number, expiration date*/)
+
+case class Payment(method: PaymentMethod, amount: BigDecimal, timestamp: java.time.Instant)
+
+case class OrderPayment(order: Order, payment: Payment)
+
+val product1 = Product(
+  id = 1L,
+  name = "Apple iPhone 16",
+  category = Category.Electronics,
+  price = BigDecimal(999.99),
+  description = "A high-end smartphone with advanced camera and AI capabilities"
+)
+val product2 = Product(
+  id = 2L,
+  name = "Nike Air Max 270",
+  category = Category.Fashion,
+  price = BigDecimal(129.99),
+  description = "A stylish and comfortable sneaker with a full-length air unit"
+)
+val product3 = Product(
+  id = 3L,
+  name = "KitchenAid Stand Mixer",
+  category = Category.HomeGoods,
+  price = BigDecimal(299.99),
+  description = "A versatile and powerful stand mixer for baking and cooking"
+)
+val customer1 = Customer(
+  id = 1L,
+  name = "John Doe",
+  email = "[email protected]",
+  address = Address(
+    street = "123 Main St",
+    city = "Anytown",
+    state = "CA",
+    zip = "12345"
+  )
+)
+val customer2 = Customer(
+  id = 2L,
+  name = "Jane Smith",
+  email = "[email protected]",
+  address = Address(
+    street = "456 Elm St",
+    city = "Othertown",
+    state = "NY",
+    zip = "67890"
+  )
+)
+val order1 = Order(
+  id = 1L,
+  customer = customer1,
+  items = List(
+    OrderItem(product1, 1),
+    OrderItem(product2, 2)
+  ),
+  status = OrderStatus.Pending
+)
+val order2 = Order(
+  id = 2L,
+  customer = customer2,
+  items = List(
+    OrderItem(product3, 1)
+  ),
+  status = OrderStatus.Shipped
+)
+val paymentMethod1 = PaymentMethod(
+  `type` = PaymentType.CreditCard,
+  details = Map(
+    "card_number" -> "1234-5678-9012-3456",
+    "expiration_date" -> "12/2026"
+  )
+)
+val paymentMethod2 = PaymentMethod(
+  `type` = PaymentType.PayPal,
+  details = Map(
+    "paypal_id" -> "[email protected]"
+  )
+)
+val payment1 = Payment(
+  method = paymentMethod1,
+  amount = BigDecimal(1259.97),
+  timestamp = java.time.Instant.parse("2025-01-03T12:30:45Z")
+)
+val payment2 = Payment(
+  method = paymentMethod2,
+  amount = BigDecimal(299.99),
+  timestamp = java.time.Instant.parse("2025-01-15T19:10:55Z")
+)
+val orderPayment1 = OrderPayment(
+  order = order1,
+  payment = payment1
+)
+val orderPayment2 = OrderPayment(
+  order = order2,
+  payment = payment2
+)
+val report = List(
+  orderPayment1,
+  orderPayment2
+)
+```
+
+## Defining the codec
+
+To derive a codec the report type (`List[OrderPayment]` type in our case) we will use `JsonCodecMaker.make` macros:
+```scala
+given JsonValueCodec[List[OrderPayment]] = JsonCodecMaker.make
+```
+
+An instance of this codec (also known as a type-class instance) is getting to be visible in the scope of subsequent
+calls of parsing and serialization methods. 
+
+## Serialization
+
+Now we are ready to serialize the report. Just need to define some entry point method and call `writeToString`.
+We will also print resulting JSON to the system output to see it as a process output:
+
+```scala
+@main def gettingStarted: Unit =
+  val json = writeToString(report)
+  println(json)
+```
+
+From this moment you can run the script and see a long JSON string on the screen.
+
+## Parsing
+
+Having the JSON string in memory you can parse it using following lines that should be pasted to the end of the
+`gettingStarted` method:
+```scala
+  val parsedReport = readFromString(json)
+  println(parsedReport)
+```
+
+Now you can rerun the script and get additionally printed `toString` representation of a report parsed from JSON string.
+
+If something gone wrong you can pick the final version of [a script for this tutorial](1-getting-started.scala) and then run it.
+
+## Challenge
+Experiment with different types of collections and try to find any collection type from the standard Scala library that
+is not supported by `JsonCodecMaker.make` macros to derive codec for serialization *and* parsing.
+
+## Recap
+In this tutorial we learned basics for parsing and serialization of complex nested data structures using `scala-cli`.
+Having definition of data structures and their instances in memory we need to:
+1. Add dependency usage and package imports of `core` and `macros` modules of jsoniter-scala 
+2. Define `given` type-class instance of `JsonValueCodec` for top-level data structure
+3. Call `writeToString` to serialize an instance of complex data structure to JSON representation
+4. Call `readFromString` to parse a complex data structure from JSON representation

docs/tutorials/1-getting-started.scala

@@ -0,0 +1,135 @@
+//> using scala 3
+//> using dep "com.github.plokhotnyuk.jsoniter-scala::jsoniter-scala-core::2.31.3"
+//> using compileOnly.dep "com.github.plokhotnyuk.jsoniter-scala::jsoniter-scala-macros::2.31.3"
+
+import com.github.plokhotnyuk.jsoniter_scala.core._
+import com.github.plokhotnyuk.jsoniter_scala.macros._
+
+enum Category extends Enum[Category]:
+  case Electronics, Fashion, HomeGoods
+
+case class Product(id: Long, name: String, category: Category, price: BigDecimal, description: String)
+
+enum OrderStatus extends Enum[OrderStatus]:
+  case Pending, Shipped, Delivered, Cancelled
+
+case class OrderItem(product: Product, quantity: Int)
+
+case class Order(id: Long, customer: Customer, items: List[OrderItem], status: OrderStatus)
+
+case class Customer(id: Long, name: String, email: String, address: Address)
+
+case class Address(street: String, city: String, state: String, zip: String)
+
+enum PaymentType extends Enum[PaymentType]:
+  case CreditCard, PayPal
+
+case class PaymentMethod(`type`: PaymentType, details: Map[String, String]/*e.g. card number, expiration date*/)
+
+case class Payment(method: PaymentMethod, amount: BigDecimal, timestamp: java.time.Instant)
+
+case class OrderPayment(order: Order, payment: Payment)
+
+val product1 = Product(
+  id = 1L,
+  name = "Apple iPhone 16",
+  category = Category.Electronics,
+  price = BigDecimal(999.99),
+  description = "A high-end smartphone with advanced camera and AI capabilities"
+)
+val product2 = Product(
+  id = 2L,
+  name = "Nike Air Max 270",
+  category = Category.Fashion,
+  price = BigDecimal(129.99),
+  description = "A stylish and comfortable sneaker with a full-length air unit"
+)
+val product3 = Product(
+  id = 3L,
+  name = "KitchenAid Stand Mixer",
+  category = Category.HomeGoods,
+  price = BigDecimal(299.99),
+  description = "A versatile and powerful stand mixer for baking and cooking"
+)
+val customer1 = Customer(
+  id = 1L,
+  name = "John Doe",
+  email = "[email protected]",
+  address = Address(
+    street = "123 Main St",
+    city = "Anytown",
+    state = "CA",
+    zip = "12345"
+  )
+)
+val customer2 = Customer(
+  id = 2L,
+  name = "Jane Smith",
+  email = "[email protected]",
+  address = Address(
+    street = "456 Elm St",
+    city = "Othertown",
+    state = "NY",
+    zip = "67890"
+  )
+)
+val order1 = Order(
+  id = 1L,
+  customer = customer1,
+  items = List(
+    OrderItem(product1, 1),
+    OrderItem(product2, 2)
+  ),
+  status = OrderStatus.Pending
+)
+val order2 = Order(
+  id = 2L,
+  customer = customer2,
+  items = List(
+    OrderItem(product3, 1)
+  ),
+  status = OrderStatus.Shipped
+)
+val paymentMethod1 = PaymentMethod(
+  `type` = PaymentType.CreditCard,
+  details = Map(
+    "card_number" -> "1234-5678-9012-3456",
+    "expiration_date" -> "12/2026"
+  )
+)
+val paymentMethod2 = PaymentMethod(
+  `type` = PaymentType.PayPal,
+  details = Map(
+    "paypal_id" -> "[email protected]"
+  )
+)
+val payment1 = Payment(
+  method = paymentMethod1,
+  amount = BigDecimal(1259.97),
+  timestamp = java.time.Instant.parse("2025-01-03T12:30:45Z")
+)
+val payment2 = Payment(
+  method = paymentMethod2,
+  amount = BigDecimal(299.99),
+  timestamp = java.time.Instant.parse("2025-01-15T19:10:55Z")
+)
+val orderPayment1 = OrderPayment(
+  order = order1,
+  payment = payment1
+)
+val orderPayment2 = OrderPayment(
+  order = order2,
+  payment = payment2
+)
+val report = List(
+  orderPayment1,
+  orderPayment2
+)
+
+given JsonValueCodec[List[OrderPayment]] = JsonCodecMaker.make
+
+@main def gettingStarted: Unit =
+  val json = writeToString(report)
+  println(json)
+  val parsedReport = readFromString(json)
+  println(parsedReport)