Switch TypeApplications to given extensions

compiler/src/dotty/tools/backend/jvm/BCodeBodyBuilder.scala

@@ -16,6 +16,7 @@ import dotty.tools.dotc.CompilationUnit
 import dotty.tools.dotc.core.Constants.*
 import dotty.tools.dotc.core.Flags.{Label => LabelFlag, _}
 import dotty.tools.dotc.core.Types.*
+import dotty.tools.dotc.core.TypeApplications.*
 import dotty.tools.dotc.core.StdNames.{nme, str}
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.transform.Erasure

compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala

@@ -17,6 +17,7 @@ import dotty.tools.dotc.core.NameKinds.*
 import dotty.tools.dotc.core.Names.TermName
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Types.*
+import dotty.tools.dotc.core.TypeApplications.*
 import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.util.Spans.*
 import dotty.tools.dotc.report

compiler/src/dotty/tools/debug/ExtractExpression.scala

@@ -8,6 +8,7 @@ import dotty.tools.dotc.core.Flags.*
 import dotty.tools.dotc.core.Names.*
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.Types.*
+import dotty.tools.dotc.core.TypeApplications.*
 import dotty.tools.dotc.core.DenotTransformers.DenotTransformer
 import dotty.tools.dotc.core.Denotations.SingleDenotation
 import dotty.tools.dotc.core.SymDenotations.SymDenotation

compiler/src/dotty/tools/debug/ResolveReflectEval.scala

@@ -12,6 +12,7 @@ import dotty.tools.dotc.core.StdNames.*
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.core.TypeErasure.ErasedValueType
 import dotty.tools.dotc.core.Types.*
+import dotty.tools.dotc.core.TypeApplications.*
 import dotty.tools.dotc.report
 import dotty.tools.dotc.transform.MegaPhase.MiniPhase
 import dotty.tools.dotc.transform.ValueClasses

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -4,6 +4,7 @@ package ast
 
 import core.*
 import util.Spans.*, Types.*, Contexts.*, Constants.*, Names.*, NameOps.*, Flags.*
+import TypeApplications.*
 import Symbols.*, StdNames.*, Trees.*, ContextOps.*
 import Decorators.*
 import Annotations.Annotation

compiler/src/dotty/tools/dotc/ast/DesugarEnums.scala

@@ -4,6 +4,7 @@ package ast
 
 import core.*
 import util.Spans.*, Types.*, Contexts.*, Constants.*, Names.*, Flags.*
+import TypeApplications.*
 import Symbols.*, StdNames.*, Trees.*
 import Decorators.*
 import util.{Property, SourceFile}

compiler/src/dotty/tools/dotc/ast/MainProxies.scala

@@ -3,6 +3,7 @@ package ast
 
 import core.*
 import Symbols.*, Types.*, Contexts.*, Decorators.*, util.Spans.*, Flags.*, Constants.*
+import TypeApplications.*
 import StdNames.{nme, tpnme}
 import ast.Trees.*
 import Names.Name

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -4,6 +4,7 @@ package ast
 
 import core.*
 import Flags.*, Trees.*, Types.*, Contexts.*
+import TypeApplications.*
 import Names.*, StdNames.*, NameOps.*, Symbols.*
 import Annotations.Annotation
 import NameKinds.ContextBoundParamName

compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala

@@ -4,6 +4,7 @@ package ast
 
 import core.*
 import Types.*, Contexts.*, Flags.*
+import TypeApplications.*
 import Symbols.*, Annotations.*, Trees.*, Symbols.*, Constants.Constant
 import Decorators.*
 

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -4,6 +4,7 @@ package ast
 
 import core.*
 import Types.*, Names.*, NameOps.*, Flags.*, util.Spans.*, Contexts.*, Constants.*
+import TypeApplications.*
 import typer.{ ConstFold, ProtoTypes }
 import SymDenotations.*, Symbols.*, Denotations.*, StdNames.*, Comments.*
 import collection.mutable.ListBuffer

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -7,6 +7,7 @@ import typer.ProtoTypes
 import core.*
 import Scopes.newScope
 import util.Spans.*, Types.*, Contexts.*, Constants.*, Names.*, Flags.*, NameOps.*
+import TypeApplications.*
 import Symbols.*, StdNames.*, Annotations.*, Trees.*, Symbols.*
 import Decorators.*, DenotTransformers.*
 import collection.{immutable, mutable}

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -4,6 +4,7 @@ package ast
 
 import core.*
 import Types.*, Contexts.*, Constants.*, Names.*, Flags.*
+import TypeApplications.*
 import dotty.tools.dotc.typer.ProtoTypes
 import Symbols.*, StdNames.*, Trees.*
 import util.{Property, SourceFile, NoSource}

compiler/src/dotty/tools/dotc/cc/CaptureSet.scala

@@ -4,6 +4,7 @@ package cc
 
 import core.*
 import Types.*, Symbols.*, Flags.*, Contexts.*, Decorators.*
+import TypeApplications.*
 import config.Printers.{capt, captDebug}
 import Annotations.Annotation
 import annotation.threadUnsafe

compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala

@@ -6,6 +6,7 @@ import core.*
 import Phases.*, DenotTransformers.*, SymDenotations.*
 import Contexts.*, Names.*, Flags.*, Symbols.*, Decorators.*
 import Types.*, StdNames.*, Denotations.*
+import TypeApplications.*
 import config.Printers.{capt, recheckr, noPrinter}
 import config.{Config, Feature}
 import ast.{tpd, untpd, Trees}

compiler/src/dotty/tools/dotc/cc/Setup.scala

@@ -6,6 +6,7 @@ import core.*
 import Phases.*, DenotTransformers.*, SymDenotations.*
 import Contexts.*, Names.*, Flags.*, Symbols.*, Decorators.*
 import Types.*, StdNames.*
+import TypeApplications.*
 import Annotations.Annotation
 import config.Feature
 import config.Printers.{capt, captDebug}

compiler/src/dotty/tools/dotc/core/Annotations.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Symbols.*, Types.*, Contexts.*, Constants.*, Phases.*
+import TypeApplications.*
 import ast.tpd, tpd.*
 import util.Spans.Span
 import printing.{Showable, Printer}

compiler/src/dotty/tools/dotc/core/CheckRealizable.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Contexts.*, Types.*, Symbols.*, Names.*, Flags.*
+import TypeApplications.*
 import Denotations.SingleDenotation
 import Decorators.*
 import collection.mutable

compiler/src/dotty/tools/dotc/core/Comments.scala

@@ -4,6 +4,7 @@ package core
 
 import ast.{ untpd, tpd }
 import Symbols.*, Contexts.*
+import TypeApplications.*
 import util.{SourceFile, ReadOnlyMap}
 import util.Spans.*
 import util.CommentParsing.*

compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Types.*
+import TypeApplications.*
 import Contexts.*
 import Symbols.*
 import Decorators.*

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -8,6 +8,7 @@ import Periods.*
 import Names.*
 import Phases.*
 import Types.*
+import TypeApplications.*
 import Symbols.*
 import Scopes.*
 import Uniques.*

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -4,6 +4,7 @@ package core
 
 import scala.annotation.{threadUnsafe => tu}
 import Types.*, Contexts.*, Symbols.*, SymDenotations.*, StdNames.*, Names.*, Phases.*
+import TypeApplications.*
 import Flags.*, Scopes.*, Decorators.*, NameOps.*, Periods.*, NullOpsDecorator.*
 import unpickleScala2.Scala2Unpickler.ensureConstructor
 import scala.collection.mutable

compiler/src/dotty/tools/dotc/core/NamerOps.scala

@@ -3,9 +3,9 @@ package dotc
 package core
 
 import Contexts.*, Symbols.*, Types.*, Flags.*, Scopes.*, Decorators.*, Names.*, NameOps.*
+import TypeApplications.*
 import SymDenotations.{LazyType, SymDenotation}, StdNames.nme
 import ContextOps.enter
-import TypeApplications.EtaExpansion
 import collection.mutable
 import config.Printers.typr
 import rewrites.Rewrites.patch

compiler/src/dotty/tools/dotc/core/PatternTypeConstrainer.scala

@@ -5,6 +5,7 @@ package core
 import Decorators.*
 import Symbols.*
 import Types.*
+import TypeApplications.*
 import Flags.*
 import Contexts.ctx
 import dotty.tools.dotc.reporting.trace

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -4,10 +4,10 @@ package core
 
 import Periods.*, Contexts.*, Symbols.*, Denotations.*, Names.*, NameOps.*, Annotations.*
 import Types.*, Flags.*, Decorators.*, DenotTransformers.*, StdNames.*, Scopes.*
+import TypeApplications.*
 import NameOps.*, NameKinds.*
 import Phases.{Phase, typerPhase, unfusedPhases}
 import Constants.Constant
-import TypeApplications.TypeParamInfo
 import Scopes.Scope
 import dotty.tools.io.AbstractFile
 import Decorators.*

compiler/src/dotty/tools/dotc/core/Symbols.scala

@@ -14,6 +14,7 @@ import Denotations.*
 import printing.Texts.*
 import printing.Printer
 import Types.*
+import TypeApplications.*
 import util.Spans.*
 import DenotTransformers.*
 import StdNames.*

compiler/src/dotty/tools/dotc/core/TypeApplications.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Types.*
+import TypeApplications.*
 import Contexts.*
 import Symbols.*
 import SymDenotations.LazyType
@@ -13,16 +14,10 @@ import StdNames.nme
 import Flags.{Module, Provisional}
 import dotty.tools.dotc.config.Config
 
-object TypeApplications {
+object TypeApplications:
 
   type TypeParamInfo = ParamInfo.Of[TypeName]
 
-  /** Assert type is not a TypeBounds instance and return it unchanged */
-  def noBounds(tp: Type): Type = tp match {
-    case tp: TypeBounds => throw new AssertionError("no TypeBounds allowed")
-    case _ => tp
-  }
-
   /** Extractor for
    *
    *    [X1: B1, ..., Xn: Bn] -> C[X1, ..., Xn]
@@ -31,7 +26,7 @@ object TypeApplications {
    *
    *  @param tycon     C
    */
-  object EtaExpansion:
+  object EtaExpansion: // note typer.EtaExpansion
 
     /** Test that the parameter bounds in a hk type lambda `[X1,...,Xn] => C[X1, ..., Xn]`
      *  contain the bounds of the type parameters of `C`. This is necessary to be able to
@@ -153,13 +148,9 @@ object TypeApplications {
         mapOver(t)
     }
   }
-}
-
-import TypeApplications.*
-
-/** A decorator that provides methods for modeling type application */
-class TypeApplications(val self: Type) extends AnyVal {
 
+  // Extensions that model type application.
+  extension (self: Type) { // braces to avoid indent
   /** The type parameters of this type are:
    *  For a ClassInfo type, the type parameters of its class.
    *  For a typeref referring to a class, the type parameters of the class.
@@ -315,7 +306,7 @@ class TypeApplications(val self: Type) extends AnyVal {
   /** Convert a type constructor `TC` which has type parameters `X1, ..., Xn`
    *  to `[X1, ..., Xn] -> TC[X1, ..., Xn]`.
    */
-  def etaExpand(using Context): Type =
+  def etaExpand(using Context): Type = // note typer.EtaExpansion.etaExpand
     val tparams = self.typeParams
     val resType = self.appliedTo(tparams.map(_.paramRef))
     self.dealias match
@@ -554,7 +545,7 @@ class TypeApplications(val self: Type) extends AnyVal {
     case _ => self.dropDependentRefinement.dealias.argInfos
 
   /** Argument types where existential types in arguments are disallowed */
-  def argTypes(using Context): List[Type] = argInfos mapConserve noBounds
+  def argTypes(using Context): List[Type] = argInfos.mapConserve(_.noBounds)
 
   /** Argument types where existential types in arguments are approximated by their lower bound */
   def argTypesLo(using Context): List[Type] = argInfos.mapConserve(_.loBound)
@@ -588,4 +579,9 @@ class TypeApplications(val self: Type) extends AnyVal {
       .orElse(self.baseType(defn.ArrayClass))
       .argInfos.headOption.getOrElse(NoType)
   }
-}
+
+  /** Assert type is not a TypeBounds instance and return it unchanged */
+  def noBounds: self.type =
+    assert(!self.isInstanceOf[TypeBounds], "no TypeBounds allowed")
+    self
+  }

compiler/src/dotty/tools/dotc/core/TypeComparer.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Types.*, Contexts.*, Symbols.*, Flags.*, Names.*, NameOps.*, Denotations.*
+import TypeApplications.*
 import Decorators.*
 import Phases.{gettersPhase, elimByNamePhase}
 import StdNames.nme

compiler/src/dotty/tools/dotc/core/TypeErasure.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Symbols.*, Types.*, Contexts.*, Flags.*, Names.*, StdNames.*, Phases.*
+import TypeApplications.*
 import Flags.JavaDefined
 import Uniques.unique
 import backend.sjs.JSDefinitions

compiler/src/dotty/tools/dotc/core/TypeEval.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Types.*, Contexts.*, Symbols.*, Constants.*, Decorators.*
+import TypeApplications.*
 import config.Printers.typr
 import reporting.trace
 import StdNames.tpnme

compiler/src/dotty/tools/dotc/core/TypeOps.scala

@@ -3,6 +3,7 @@ package dotc
 package core
 
 import Contexts.*, Types.*, Symbols.*, Names.*, NameKinds.*, Flags.*
+import TypeApplications.*
 import SymDenotations.*
 import util.Spans.*
 import util.Stats

compiler/src/dotty/tools/dotc/core/TypeUtils.scala

@@ -4,6 +4,7 @@ package core
 
 import TypeErasure.ErasedValueType
 import Types.*, Contexts.*, Symbols.*, Flags.*, Decorators.*, SymDenotations.*
+import TypeApplications.*
 import Names.{Name, TermName}
 import Constants.Constant
 

compiler/src/dotty/tools/dotc/core/Types.scala

@@ -19,6 +19,7 @@ import Denotations.*
 import Periods.*
 import CheckRealizable.*
 import Variances.{Variance, setStructuralVariances, Invariant}
+import TypeApplications.*
 import typer.Nullables
 import util.Stats.*
 import util.{SimpleIdentityMap, SimpleIdentitySet}
@@ -2132,8 +2133,7 @@ object Types extends TypeUtils {
     /** Is the `hash` of this type the same for all possible sequences of enclosing binders? */
     def hashIsStable: Boolean = true
   }
-
-  // end Type
+  end Type
 
 // ----- Type categories ----------------------------------------------
 
@@ -7160,8 +7160,6 @@ object Types extends TypeUtils {
 
   // ----- Helpers and Decorator implicits --------------------------------------
 
-  implicit def decorateTypeApplications(tpe: Type): TypeApplications = new TypeApplications(tpe)
-
   extension (tps1: List[Type]) {
     @tailrec def hashIsStable: Boolean =
       tps1.isEmpty || tps1.head.hashIsStable && tps1.tail.hashIsStable

compiler/src/dotty/tools/dotc/core/Variances.scala

@@ -2,7 +2,7 @@ package dotty.tools.dotc
 package core
 
 import Types.*, Contexts.*, Flags.*, Symbols.*, Annotations.*
-import TypeApplications.TypeParamInfo
+import TypeApplications.*
 import Decorators.*
 
 object Variances {

compiler/src/dotty/tools/dotc/core/classfile/ClassfileParser.scala

@@ -8,6 +8,7 @@ import scala.language.unsafeNulls
 import dotty.tools.tasty.{ TastyReader, TastyHeaderUnpickler }
 
 import Contexts.*, Symbols.*, Types.*, Names.*, StdNames.*, NameOps.*, Scopes.*, Decorators.*
+import TypeApplications.*
 import SymDenotations.*, unpickleScala2.Scala2Unpickler.*, Constants.*, Annotations.*, util.Spans.*
 import Phases.*
 import ast.{ tpd, untpd }

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -9,6 +9,7 @@ import Comments.docCtx
 import Contexts.*
 import Symbols.*
 import Types.*
+import TypeApplications.*
 import Scopes.*
 import SymDenotations.*
 import Denotations.*

compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala

@@ -10,6 +10,7 @@ import java.lang.Float.intBitsToFloat
 import java.lang.Double.longBitsToDouble
 
 import Contexts.*, Symbols.*, Types.*, Scopes.*, SymDenotations.*, Names.*, NameOps.*
+import TypeApplications.*
 import StdNames.*, Denotations.*, NameOps.*, Flags.*, Constants.*, Annotations.*, Phases.*
 import NameKinds.{Scala2MethodNameKinds, SuperAccessorName, ExpandedName}
 import util.Spans.*

compiler/src/dotty/tools/dotc/inlines/Inliner.scala

@@ -4,6 +4,7 @@ package inlines
 
 import ast.*, core.*
 import Flags.*, Symbols.*, Types.*, Decorators.*, Constants.*, Contexts.*
+import TypeApplications.*
 import StdNames.nme
 import typer.*
 import Names.Name