Scaladoc: new heuristic for extension method parameter extraction

scaladoc-testcases/src/tests/extensionParams.scala

@@ -1,22 +1,54 @@
 package tests.extensionParams
 
+trait Animal
+
 extension [A](thiz: A)
-  def toTuple2[B](that: B): (A, B) = thiz -> that
+  def toTuple2[B](that: B): (A, B)
+   = thiz -> that
 
 extension [A](a: A)(using Int)
-  def f[B](b: B): (A, B) = ???
+  def f1[B](b: B): (A, B)
+  = ???
 
 extension [A](a: A)(using Int)
-  def ff(b: A): (A, A) = ???
+  def f2(b: A): (A, A)
+  = ???
 
 extension [A](a: A)(using Int)
-  def fff(using String)(b: A): (A, A) = ???
+  def f3(using String)(b: A): (A, A)
+  = ???
 
 extension (a: Char)(using Int)
-  def ffff(using String)(b: Int): Unit = ???
+  def f4(using String)(b: Int): Unit
+  = ???
 
 extension (a: Char)(using Int)
-  def fffff[B](using String)(b: B): Unit = ???
+  def f5[B](using String)(b: B): Unit
+  = ???
+
+extension [A <: List[Char]](a: Int)(using Int)
+  def f6[B](b: B): (A, B)
+  = ???
+
+extension [A <: List[Char]](using String)(using Unit)(a: A)(using Int)(using Number)
+  def f7[B, C](b: B)(c: C): (A, B)
+  = ???
+
+extension [A <: List[Char]](using String)(using Unit)(a: A)(using Int)(using Number)
+  def f8(b: Any)(c: Any): Any
+  = ???
+
+extension [A <: List[Char]](using String)(using Unit)(a: A)(using Int)(using Number)
+  def f9[B, C](using Int)(b: B)(c: C): (A, B)
+  = ???
+
+extension [A <: List[Char]](using String)(using Unit)(a: A)(using Int)(using Number)
+  def f10(using Int)(b: Any)(c: Any): Any
+   = ???
+
+  def f12(using Int)(b: A)(c: String): Number
+   = ???
 
-extension [A <: List[Char]](a: A)(using Int)
-  def ffffff[B](b: B): (A, B) = ???
+extension (using String)(using Unit)(a: Animal)(using Int)(using Number)
+  def f11(b: Any)(c: Any): Any
+  = ???

scaladoc/resources/dotty_res/styles/scalastyle.css

@@ -988,8 +988,7 @@ footer .socials {
   color: var(--type);
 }
 
-.signature *[t="t"] {
-  /* Types with links */
+.signature *[t="t"] { /* Types with links */
   color: var(--type-link);
 }
 

scaladoc/src/dotty/tools/scaladoc/renderers/MemberRenderer.scala

@@ -319,8 +319,8 @@ class MemberRenderer(signatureRenderer: SignatureRenderer)(using DocContext) ext
             .functionParameters(on.argsLists)
             .content
           val sig = typeSig ++ Signature(Plain(s"(${on.name}: ")) ++ on.signature ++ Signature(Plain(")")) ++ argsSig
-          MGroup(span(cls := "groupHeader")(sig.map(renderElement(_))), members.sortBy(_.name).toSeq, on.name)
-      }.toSeq
+          MGroup(span(cls := "groupHeader")(sig.map(renderElement(_))), members.sortBy(_.name).toSeq, on.name) -> on.position
+      }.toSeq.sortBy(_._2).map(_._1)
 
     div(cls := "membersList expand")(
     h2(cls := "h500")("Members list"),

scaladoc/src/dotty/tools/scaladoc/renderers/Resources.scala

@@ -166,7 +166,15 @@ trait Resources(using ctx: DocContext) extends Locations, Writer:
 
     def extensionTarget(member: Member): String =
       member.kind match
-        case Kind.Extension(on, _) => flattenToText(on.signature)
+        case Kind.Extension(on, _) =>
+          val typeSig = SignatureBuilder()
+            .keyword("extension ")
+            .generics(on.typeParams)
+            .content
+          val argsSig = SignatureBuilder()
+            .functionParameters(on.argsLists)
+            .content
+          flattenToText(typeSig ++ argsSig)
         case _ => ""
 
     def processPage(page: Page, pageFQName: List[String]): Seq[(JSON, Seq[String])] =

scaladoc/src/dotty/tools/scaladoc/tasty/ClassLikeSupport.scala

@@ -519,14 +519,13 @@ trait ClassLikeSupport:
         // Documenting method slightly different then its definition is withing the 'undefiend behaviour'.
         symbol.paramSymss.flatten.find(_.name == name).exists(_.flags.is(Flags.Implicit))
 
-    def handlePolyType(polyType: PolyType): MemberInfo =
-      MemberInfo(polyType.paramNames.zip(polyType.paramBounds).toMap, List.empty, polyType.resType)
+    def handlePolyType(memberInfo: MemberInfo, polyType: PolyType): MemberInfo =
+      MemberInfo(polyType.paramNames.zip(polyType.paramBounds).toMap, memberInfo.paramLists, polyType.resType)
 
     def handleMethodType(memberInfo: MemberInfo, methodType: MethodType): MemberInfo =
       val rawParams = methodType.paramNames.zip(methodType.paramTypes).toMap
       val (evidences, notEvidences) = rawParams.partition(e => isSyntheticEvidence(e._1))
 
-
       def findParamRefs(t: TypeRepr): Seq[ParamRef] = t match
         case paramRef: ParamRef => Seq(paramRef)
         case AppliedType(_, args) => args.flatMap(findParamRefs)
@@ -563,7 +562,7 @@ trait ClassLikeSupport:
       MemberInfo(memberInfo.genericTypes, memberInfo.paramLists, byNameType.underlying)
 
     def recursivelyCalculateMemberInfo(memberInfo: MemberInfo): MemberInfo = memberInfo.res match
-      case p: PolyType => recursivelyCalculateMemberInfo(handlePolyType(p))
+      case p: PolyType => recursivelyCalculateMemberInfo(handlePolyType(memberInfo, p))
       case m: MethodType => recursivelyCalculateMemberInfo(handleMethodType(memberInfo, m))
       case b: ByNameType => handleByNameType(memberInfo, b)
       case _ => memberInfo

scaladoc/src/dotty/tools/scaladoc/tasty/SymOps.scala

@@ -147,28 +147,43 @@ object SymOps:
 
     def extendedSymbol: Option[reflect.ValDef] =
       import reflect.*
-      Option.when(sym.isExtensionMethod){
-        val termParamss = sym.tree.asInstanceOf[DefDef].termParamss
-        if sym.isLeftAssoc || termParamss.size == 1 then termParamss(0).params(0)
-        else termParamss(1).params(0)
+      if sym.isExtensionMethod then
+        sym.extendedTermParamLists.find(param => !param.isImplicit && !param.isGiven).flatMap(_.params.headOption)
+      else None
+
+    def splitExtensionParamList: (List[reflect.ParamClause], List[reflect.ParamClause]) =
+      import reflect.*
+
+      def getPositionStartOption(pos: Option[Position]): Option[Int] = pos.flatMap {
+        case dotty.tools.dotc.util.NoSourcePosition => None
+        case pos: Position => Some(pos.start)
       }
 
+      def comparePositionStarts(posA: Option[Position], posB: Option[Position]): Option[Boolean] =
+        for {
+          startA <- getPositionStartOption(posA)
+          startB <- getPositionStartOption(posB)
+        } yield startA < startB
+
+      sym.tree match
+        case tree: DefDef =>
+          tree.paramss.partition(_.params.headOption.flatMap(param =>
+            comparePositionStarts(param.symbol.pos, tree.symbol.pos)).getOrElse(false)
+          )
+        case _ => Nil -> Nil
+
     def extendedTypeParams: List[reflect.TypeDef] =
       import reflect.*
-      val method = sym.tree.asInstanceOf[DefDef]
-      method.leadingTypeParams
+      sym.tree match
+        case tree: DefDef =>
+          tree.leadingTypeParams
+        case _ => Nil
 
     def extendedTermParamLists: List[reflect.TermParamClause] =
       import reflect.*
-      if sym.nonExtensionLeadingTypeParams.nonEmpty then
-        sym.nonExtensionParamLists.takeWhile {
-          case _: TypeParamClause => false
-          case _ => true
-        }.collect {
-          case tpc: TermParamClause => tpc
-        }
-      else
-        List.empty
+      sym.splitExtensionParamList._1.collect {
+        case tpc: TermParamClause => tpc
+      }
 
     def nonExtensionTermParamLists: List[reflect.TermParamClause] =
       import reflect.*
@@ -185,14 +200,7 @@ object SymOps:
         }
 
     def nonExtensionParamLists: List[reflect.ParamClause] =
-      import reflect.*
-      val method = sym.tree.asInstanceOf[DefDef]
-      if sym.isExtensionMethod then
-        val params = method.paramss
-        val toDrop = if method.leadingTypeParams.nonEmpty then 2 else 1
-        if sym.isLeftAssoc || params.size == 1 then params.drop(toDrop)
-        else params.head :: params.tail.drop(toDrop)
-      else method.paramss
+      sym.splitExtensionParamList._2
 
     def nonExtensionLeadingTypeParams: List[reflect.TypeDef] =
       import reflect.*

scaladoc/test/dotty/tools/scaladoc/signatures/TranslatableSignaturesTestCases.scala

@@ -41,6 +41,8 @@ class MergedPackageSignatures extends SignatureTest("mergedPackage", SignatureTe
 
 class ExtensionMethodSignature extends SignatureTest("extensionMethodSignatures", SignatureTest.all)
 
+class ExtensionMethodParamsSignature extends SignatureTest("extensionParams", SignatureTest.all)
+
 class ClassModifiers extends SignatureTest("classModifiers", SignatureTest.classlikeKinds)
 
 class EnumSignatures extends SignatureTest("enumSignatures", SignatureTest.all)