WIP: Start porting to Scala 3

.scalafmt.conf

@@ -1,11 +1,11 @@
-version = "3.5.9"
+version = "3.7.17"
+runner.dialect=scala213
 
 style = defaultWithAlign
 
-danglingParentheses = true
-indentOperator = spray
+danglingParentheses.preset = true
+indentOperator.preset = spray
 maxColumn = 140
 project.excludeFilters = [".*\\.sbt"]
 rewrite.rules = [AsciiSortImports, RedundantBraces, RedundantParens]
 spaces.inImportCurlyBraces = true
-unindentTopLevelOperators = true

build.sbt

@@ -6,9 +6,9 @@ enablePlugins(GitBranchPrompt)
 organization := "com.davegurnell"
 name         := "bridges"
 
-ThisBuild / scalaVersion       := "2.13.8"
+ThisBuild / scalaVersion       := "3.5.0"
 
-ThisBuild / crossScalaVersions := Seq("2.13.8", "2.12.17")
+ThisBuild / crossScalaVersions := Seq("2.13.13", "3.5.0")
 
 ThisBuild / scalacOptions ++= {
   CrossVersion.partialVersion(scalaVersion.value) match {
@@ -29,6 +29,15 @@ ThisBuild / scalacOptions ++= {
         "-Xfatal-warnings",
       )
 
+    case Some((3, _)) =>
+      Seq(
+        "-feature",
+        "-unchecked",
+        "-deprecation",
+        "-Xfatal-warnings",
+        "-old-syntax",
+      )
+
     case _ =>
       Seq(
         "-feature",
@@ -41,14 +50,25 @@ ThisBuild / scalacOptions ++= {
 }
 
 ThisBuild / libraryDependencies ++= Seq(
-  "com.chuusai"       %% "shapeless"          % "2.3.10",
   "com.davegurnell"   %% "unindent"           % "1.8.0",
   "org.apache.commons" % "commons-text"       % "1.9",
   "org.scalatest"     %% "scalatest"          % "3.2.13" % Test,
   "eu.timepit"        %% "refined"            % "0.10.1" % Provided,
-  "eu.timepit"        %% "refined-shapeless"  % "0.10.1" % Provided
 )
 
+ThisBuild / libraryDependencies ++= {
+  CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((2, _)) =>
+      Seq(
+        "com.chuusai" %% "shapeless"         % "2.3.10",
+        "eu.timepit"  %% "refined-shapeless" % "0.10.1" % Provided
+      )
+
+    case _ =>
+      Seq.empty
+  }
+}
+
 // Versioning -----------------------------------
 
 ThisBuild / versionScheme := Some("early-semver")

project/build.properties

@@ -1 +1 @@
-sbt.version=1.7.1
+sbt.version=1.10.0

project/metals.sbt

@@ -1,4 +1,6 @@
 // DO NOT EDIT! This file is auto-generated.
+
 // This file enables sbt-bloop to create bloop config files.
 
-addSbtPlugin("ch.epfl.scala" % "sbt-bloop" % "1032048a")
+addSbtPlugin("ch.epfl.scala" % "sbt-bloop" % "1.5.13")
+

project/project/metals.sbt

@@ -0,0 +1,6 @@
+// DO NOT EDIT! This file is auto-generated.
+
+// This file enables sbt-bloop to create bloop config files.
+
+addSbtPlugin("ch.epfl.scala" % "sbt-bloop" % "1.5.13")
+

project/project/project/metals.sbt

@@ -0,0 +1,6 @@
+// DO NOT EDIT! This file is auto-generated.
+
+// This file enables sbt-bloop to create bloop config files.
+
+addSbtPlugin("ch.epfl.scala" % "sbt-bloop" % "1.5.13")
+

src/main/scala-2/bridges/core/DerivedEncoderInstances.scala

@@ -0,0 +1,62 @@
+package bridges.core
+
+import shapeless._
+import shapeless.labelled.FieldType
+
+import scala.reflect.runtime.universe.WeakTypeTag
+
+trait DerivedEncoderInstances extends DerivedEncoderInstances1 {
+  implicit def valueClassEncoder[A <: AnyVal, B](implicit unwrapped: Unwrapped.Aux[A, B], encoder: BasicEncoder[B]): BasicEncoder[A] =
+    pure(encoder.encode)
+}
+
+trait DerivedEncoderInstances1 extends DerivedEncoderInstances0 {
+  import Type._
+
+  implicit val hnilProdEncoder: ProdEncoder[HNil] =
+    pureProd(Prod(Nil))
+
+  implicit def hconsProdEncoder[K <: Symbol, H, T <: HList](implicit
+      witness: Witness.Aux[K],
+      hEnc: Lazy[BasicEncoder[H]],
+      tEnc: ProdEncoder[T]
+  ): ProdEncoder[FieldType[K, H] :: T] = {
+    val name = witness.value.name
+    val head = hEnc.value.encode
+    val tail = tEnc.encode
+    pureProd(Prod((name -> head) +: tail.fields))
+  }
+
+  implicit def cnilSumEncoder: SumEncoder[CNil] =
+    pureSum(Sum(Nil))
+
+  implicit def cconsSumEncoder[K <: Symbol, H, T <: Coproduct](implicit
+      witness: Witness.Aux[K],
+      hEnc: Lazy[ProdEncoder[H]],
+      tEnc: SumEncoder[T]
+  ): SumEncoder[FieldType[K, H] :+: T] = {
+    val name    = witness.value.name
+    val product = hEnc.value.encode
+    val tail    = tEnc.encode
+    pureSum(Sum((name -> product) +: tail.products))
+  }
+
+  implicit def genericProdEncoder[A, R](implicit
+      gen: LabelledGeneric.Aux[A, R],
+      enc: Lazy[ProdEncoder[R]]
+  ): ProdEncoder[A] =
+    pureProd(enc.value.encode)
+
+  implicit def genericSumEncoder[A, R](implicit
+      gen: LabelledGeneric.Aux[A, R],
+      enc: Lazy[SumEncoder[R]]
+  ): SumEncoder[A] =
+    pureSum(enc.value.encode)
+}
+
+trait DerivedEncoderInstances0 extends EncoderConstructors {
+  import Type._
+
+  implicit def genericBasicEncoder[A](implicit low: LowPriority, tpeTag: WeakTypeTag[A]): BasicEncoder[A] =
+    pure(Ref(TypeName.getTypeName[A]))
+}

src/main/scala-2/bridges/core/TypeName.scala

@@ -0,0 +1,15 @@
+package bridges.core
+
+import scala.reflect.runtime.universe.WeakTypeTag
+
+object TypeName {
+  // NOTE: we can't use `shapeless.Typeable` in here as it breaks the code for recursive types like
+  //   final case class Recursive(head: Int, tail: Option[Recursive])
+  //
+  // The only solution I found is to use a `WeakTypeTag` from scala runtime,
+  // which seems to manage the recursivity OK.
+  def getTypeName[A](implicit tpeTag: WeakTypeTag[A]): String = {
+    val fullName = tpeTag.tpe.typeSymbol.fullName
+    fullName.split('.').last
+  }
+}

src/main/scala/bridges/core/syntax.scala → src/main/scala-2/bridges/core/syntax.scala

@@ -1,26 +1,17 @@
 package bridges.core
 
 import shapeless.Lazy
+
 import scala.reflect.runtime.universe.WeakTypeTag
 
 object syntax extends RenamableSyntax {
   import Type._
 
-  // NOTE: we can't use `shapeless.Typeable` in here as it breaks the code for recursive types like
-  //   final case class Recursive(head: Int, tail: Option[Recursive])
-  //
-  // The only solution I found is to use a `WeakTypeTag` from scala runtime,
-  // which seems to manage the recursivity OK.
-  def getCleanTagName[A](implicit tpeTag: WeakTypeTag[A]): String = {
-    val fullName = tpeTag.tpe.typeSymbol.fullName
-    fullName.split('.').last
-  }
-
   def encode[A: Encoder]: Type =
     Encoder[A].encode
 
   def decl[A](implicit tpeTag: WeakTypeTag[A], encoder: Lazy[Encoder[A]]): Decl =
-    DeclF(getCleanTagName[A], encoder.value.encode)
+    DeclF(TypeName.getTypeName[A], encoder.value.encode)
 
   // To be used for classes with generic parameters as we can't use shapeless to derive them
   def decl(name: String, params: String*)(tpe: Type): Decl =

src/main/scala/bridges/flow/syntax.scala → src/main/scala-2/bridges/flow/syntax.scala

@@ -1,8 +1,8 @@
 package bridges.flow
 
 import bridges.core._
-import bridges.core.syntax.getCleanTagName
 import shapeless.Lazy
+
 import scala.language.implicitConversions
 import scala.reflect.runtime.universe.WeakTypeTag
 
@@ -13,7 +13,7 @@ object syntax extends RenamableSyntax {
     encoder.encode
 
   def decl[A](implicit tpeTag: WeakTypeTag[A], encoder: Lazy[FlowEncoder[A]]): FlowDecl =
-    DeclF(getCleanTagName[A], encoder.value.encode)
+    DeclF(TypeName.getTypeName[A], encoder.value.encode)
 
   def decl(name: String, params: String*)(tpe: FlowType): FlowDecl =
     DeclF(name, params.toList, tpe)

src/main/scala/bridges/typescript/syntax.scala → src/main/scala-2/bridges/typescript/syntax.scala

@@ -1,10 +1,10 @@
 package bridges.typescript
 
-import bridges.core.{ DeclF, Encoder, RenamableSyntax }
-import bridges.core.syntax.getCleanTagName
+import bridges.core.{ DeclF, RenamableSyntax, TypeName }
 import shapeless.Lazy
-import scala.reflect.runtime.universe.WeakTypeTag
+
 import scala.language.implicitConversions
+import scala.reflect.runtime.universe.WeakTypeTag
 
 object syntax extends RenamableSyntax {
   import TsType._
@@ -13,7 +13,7 @@ object syntax extends RenamableSyntax {
     encoder.encode
 
   def decl[A](implicit tpeTag: WeakTypeTag[A], encoder: Lazy[TsEncoder[A]]): TsDecl =
-    DeclF(getCleanTagName[A], encoder.value.encode)
+    DeclF(TypeName.getTypeName[A], encoder.value.encode)
 
   def decl(name: String, params: String*)(tpe: TsType): TsDecl =
     DeclF(name, params.toList, tpe)

src/main/scala-3/bridges/core/DerivedEncoderInstances.scala

@@ -0,0 +1,64 @@
+package bridges.core
+
+import scala.compiletime._
+import scala.deriving._
+
+trait DerivedEncoderInstances extends DerivedEncoderInstances1 {
+  // given valueClassEncoder[A <: AnyVal, B](implicit encoder: BasicEncoder[B]): BasicEncoder[A] =
+  //   ???
+}
+
+trait DerivedEncoderInstances1 extends DerivedEncoderInstances0 {
+  inline given allEncoders[A <: Tuple]: List[Encoder[Any]] = {
+    inline erasedValue[A] match {
+      case _: EmptyTuple => Nil
+      case _: (h *: t) => summonInline[Encoder[h]].asInstanceOf[Encoder[Any]] :: allEncoders[t]
+    }
+  }
+
+  inline given allProdEncoders[A <: Tuple]: List[ProdEncoder[Any]] = {
+    inline erasedValue[A] match {
+      case _: EmptyTuple => Nil
+      case _: (h *: t) => summonInline[ProdEncoder[h]].asInstanceOf[ProdEncoder[Any]] :: allProdEncoders[t]
+    }
+  }
+
+  private inline def allLabels[A <: Tuple]: List[String] = {
+    inline erasedValue[A] match {
+      case _: EmptyTuple => Nil
+      case _: (h *: t)  => constValue[h].asInstanceOf[String] :: allLabels[t]
+    }
+  }
+
+  inline given deriveEncoder[A](using mirror: Mirror.Of[A]): Encoder[A] = {
+    lazy val name = TypeName.getTypeName[A]
+
+    println(s"derivedEncoder[${name}]")
+
+    lazy val labels: List[String] =
+      allLabels[mirror.MirroredElemLabels]
+
+    inline mirror match {
+      case mirror: Mirror.ProductOf[A] => prodEncoder(mirror, labels)
+      case mirror: Mirror.SumOf[A]     => sumEncoder(mirror, labels)
+    }
+  }
+
+  private inline def prodEncoder[A](mirror: Mirror.ProductOf[A], labels: List[String]): Encoder[A] = {
+    lazy val types: List[Type] = allEncoders[mirror.MirroredElemTypes].map(_.encode)
+    pureProd(Type.Prod(labels.zip(types)))
+  }
+
+  private inline def sumEncoder[A](mirror: Mirror.SumOf[A], labels: List[String]): Encoder[A] = {
+    lazy val types: List[Type.Prod] = allProdEncoders[mirror.MirroredElemTypes].map(_.encode)
+    pure(Type.Sum(labels.zip(types)))
+  }
+}
+
+trait DerivedEncoderInstances0 extends EncoderConstructors {
+  inline given genericBasicEncoder[A]: BasicEncoder[A] = {
+    lazy val name = TypeName.getTypeName[A]
+    println(s"genericBasicEncoder[${name}]")
+    pure(Type.Ref(name))
+  }
+}

src/main/scala-3/bridges/core/TypeName.scala

@@ -0,0 +1,14 @@
+package bridges.core
+
+import scala.quoted.*
+
+object TypeName {
+  inline def getTypeName[T]: String =
+    ${ getTypeNameImpl[T] }
+
+  private def getTypeNameImpl[T: Type](using Quotes): Expr[String] = {
+    import quotes.reflect.*
+    val typeRepr = TypeRepr.of[T]
+    Expr(typeRepr.show.split("\\.").last)
+  }
+}

src/main/scala-3/bridges/core/syntax.scala

@@ -0,0 +1,28 @@
+package bridges.core
+
+object syntax extends RenamableSyntax {
+  import Type._
+
+  def encode[A: Encoder]: Type =
+    Encoder[A].encode
+
+  inline def decl[A](implicit encoder: => Encoder[A]): Decl =
+    DeclF(TypeName.getTypeName[A], encoder.encode)
+
+  def decl(name: String, params: String*)(tpe: Type): Decl =
+    DeclF(name, params.toList, tpe)
+
+  def prod(fields: (String, Type)*): Prod =
+    Prod(fields.toList)
+
+  def sum(products: (String, Prod)*): Sum =
+    Sum(products.toList)
+
+  def dict(keyType: Type, valueType: Type): Type =
+    Dict(keyType, valueType)
+
+  implicit class StringDeclOps(str: String) {
+    def :=[A](tpe: A): DeclF[A] =
+      DeclF(str, tpe)
+  }
+}