Implemented configurable derivation

modules/benchmarks/src/main/scala/json/bench/tethysjson/TethysBench.scala

@@ -11,8 +11,8 @@ import json.bench.{DataReader, DataWriter}
   */
 object TethysBench {
 
-  implicit val dataWriter: JsonWriter[Data] = jsonWriter[Data]
-  implicit val dataReader: JsonReader[Data] = jsonReader[Data]
+  implicit val dataWriter: JsonWriter[Data] = JsonWriter.derived[Data]
+  implicit val dataReader: JsonReader[Data] = JsonReader.derived[Data]
 
   object TethysJacksonDataProcessor extends DataWriter with DataReader {
 

modules/core/src/main/scala-2.12/tethys/derivation/JsonObjectWriterDerivation.scala

@@ -0,0 +1,6 @@
+package tethys.derivation
+
+
+private [tethys] trait JsonObjectWriterDerivation {
+
+}

modules/core/src/main/scala-2.13+/tethys/derivation/JsonObjectWriterDerivation.scala

@@ -0,0 +1,6 @@
+package tethys.derivation
+
+
+private [tethys] trait JsonObjectWriterDerivation {
+
+}

modules/core/src/main/scala-3/tethys/JsonConfig.scala

@@ -0,0 +1,10 @@
+package tethys
+
+sealed trait JsonConfig[A]:
+  def discriminateBy[Field](select: A => Field): JsonConfig[A]
+
+
+object JsonConfig:
+  @scala.annotation.compileTimeOnly("Config must be an inlined given or provided directly to 'derived'")
+  def configure[A]: JsonConfig[A] =
+    throw IllegalStateException("Config must be an inlined given or provided directly to 'derived'")

modules/core/src/main/scala-3/tethys/JsonFieldStyle.scala

@@ -0,0 +1,46 @@
+package tethys
+
+import java.util.regex.Pattern
+
+
+enum JsonFieldStyle {
+  case Capitalize, Uncapitalize, LowerCase, UpperCase
+
+  case KebabCase, LowerKebabCase, UpperKebabCase, CapitalizedKebabCase
+
+  case SnakeCase, LowerSnakeCase, UpperSnakeCase, CapitalizedSnakeCase
+}
+
+private[tethys]
+object JsonFieldStyle:
+  private val regexp1: Pattern = Pattern.compile("([A-Z]+)([A-Z][a-z])")
+  private val regexp2: Pattern = Pattern.compile("([a-z\\d])([A-Z])")
+  private val replacement: String = "$1_$2"
+  private val snakeCase: String => String = splitName(_).mkString("_")
+  private val kebabcase: String => String = splitName(_).mkString("-")
+  private val capitalize: String => String = _.capitalize
+  private val uncapitalize: String => String = (field: String) => field.updated(0, field.charAt(0).toLower)
+  private val lowercase: String => String = _.toLowerCase()
+  private val uppercase: String => String = _.toUpperCase()
+
+  def applyStyle(string: String, style: JsonFieldStyle): String =
+    style match
+      case JsonFieldStyle.Capitalize => capitalize(string)
+      case JsonFieldStyle.Uncapitalize => uncapitalize(string)
+      case JsonFieldStyle.LowerCase => lowercase(string)
+      case JsonFieldStyle.UpperCase => uppercase(string)
+
+      case JsonFieldStyle.KebabCase => kebabcase(string)
+      case JsonFieldStyle.LowerKebabCase => (kebabcase andThen lowercase)(string)
+      case JsonFieldStyle.UpperKebabCase => (kebabcase andThen uppercase)(string)
+      case JsonFieldStyle.CapitalizedKebabCase => (kebabcase andThen capitalize)(string)
+
+      case JsonFieldStyle.SnakeCase => snakeCase(string)
+      case JsonFieldStyle.LowerSnakeCase => (snakeCase andThen lowercase)(string)
+      case JsonFieldStyle.UpperSnakeCase => (snakeCase andThen uppercase)(string)
+      case JsonFieldStyle.CapitalizedSnakeCase => (snakeCase andThen capitalize)(string)
+
+
+  private def splitName(name: String): List[String] =
+    val first = JsonFieldStyle.regexp1.matcher(name).replaceAll(JsonFieldStyle.replacement)
+    JsonFieldStyle.regexp2.matcher(first).replaceAll(JsonFieldStyle.replacement).split("_").toList

modules/core/src/main/scala-3/tethys/OrdinalEnumJsonReader.scala

@@ -0,0 +1,21 @@
+package tethys
+
+import tethys.readers.{FieldName, ReaderError}
+import tethys.readers.tokens.TokenIterator
+
+trait OrdinalEnumJsonReader[A] extends JsonReader[A]
+
+object OrdinalEnumJsonReader:
+  inline def derived[A <: scala.reflect.Enum]: OrdinalEnumJsonReader[A] =
+    new OrdinalEnumJsonReader[A]:
+      def read(it: TokenIterator)(implicit fieldName: FieldName): A =
+        if it.currentToken().isNumberValue then
+          val res = it.int()
+          it.next()
+          try derivation.EnumCompanion.getByOrdinal[A](res)
+          catch
+            case ex: NoSuchElementException =>
+              ReaderError.wrongJson(s"Unknown enum ordinal: $res")
+        else
+          ReaderError.wrongJson(s"Expected int value but found: ${it.currentToken()}")
+

modules/core/src/main/scala-3/tethys/OrdinalEnumWriter.scala → modules/core/src/main/scala-3/tethys/OrdinalEnumJsonWriter.scala

@@ -2,10 +2,10 @@ package tethys
 import tethys.writers.tokens.TokenWriter
 
 
-trait OrdinalEnumWriter[A] extends JsonWriter[A]
+trait OrdinalEnumJsonWriter[A] extends JsonWriter[A]
 
-object OrdinalEnumWriter:
-  inline def derived[A <: scala.reflect.Enum]: OrdinalEnumWriter[A] =
+object OrdinalEnumJsonWriter:
+  inline def derived[A <: scala.reflect.Enum]: OrdinalEnumJsonWriter[A] =
     (value: A, tokenWriter: TokenWriter) => tokenWriter.writeNumber(value.ordinal)
 
   inline def withLabel[A <: scala.reflect.Enum](label: String): JsonObjectWriter[A] =

modules/core/src/main/scala-3/tethys/StringEnumJsonReader.scala

@@ -0,0 +1,23 @@
+package tethys
+
+import tethys.readers.{FieldName, ReaderError}
+import tethys.readers.tokens.TokenIterator
+
+trait StringEnumJsonReader[A] extends JsonReader[A]
+
+object StringEnumJsonReader:
+  inline def derived[A <: scala.reflect.Enum]: StringEnumJsonReader[A] =
+    new StringEnumJsonReader[A]:
+      def read(it: TokenIterator)(implicit fieldName: FieldName): A =
+        if it.currentToken().isStringValue then
+          val res = it.string()
+          it.next()
+          try
+            derivation.EnumCompanion.getByName[A](res)
+          catch 
+            case ex: NoSuchElementException =>
+              ReaderError.wrongJson(s"Unknown enum name: $res")
+        else
+          ReaderError.wrongJson(s"Expected string value but found: ${it.currentToken()}")
+
+

modules/core/src/main/scala-3/tethys/StringEnumWriter.scala → modules/core/src/main/scala-3/tethys/StringEnumJsonWriter.scala

@@ -1,10 +1,10 @@
 package tethys
 import tethys.writers.tokens.TokenWriter
 
-trait StringEnumWriter[A] extends JsonWriter[A]
+trait StringEnumJsonWriter[A] extends JsonWriter[A]
 
-object StringEnumWriter:
-  inline def derived[A <: scala.reflect.Enum]: StringEnumWriter[A] = 
+object StringEnumJsonWriter:
+  inline def derived[A <: scala.reflect.Enum]: StringEnumJsonWriter[A] =
     (value: A, tokenWriter: TokenWriter) => tokenWriter.writeString(value.toString)
 
   inline def withLabel[A <: scala.reflect.Enum](label: String): JsonObjectWriter[A] =