Separate MatchReducer (Issue 24120)

Author: Lluc24

.git-blame-ignore-revs

@@ -1 +1,3 @@
 46a26945a172429740ebdd1fc83517130670080b
+# Move MatchReducer to its own file (from TypeComparer.scala to MatchReducer.scala)
+31aac54ad1a8079cb53903437a27b2de81b82de6

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

@@ -1,3 +1,34 @@
+package dotty.tools
+package dotc
+package core
+
+import Types.*, Contexts.*, Symbols.*, Flags.*, Names.*, NameOps.*, Denotations.*
+import Decorators.*
+import Phases.{gettersPhase, elimByNamePhase}
+import StdNames.nme
+import TypeOps.refineUsingParent
+import collection.mutable
+import util.{Stats, NoSourcePosition, EqHashMap}
+import config.Config
+import config.Feature.{migrateTo3, sourceVersion}
+import config.Printers.{subtyping, gadts, matchTypes, capt, noPrinter}
+import config.SourceVersion
+import TypeErasure.{erasedLub, erasedGlb}
+import TypeApplications.*
+import Variances.{Variance, variancesConform}
+import Constants.Constant
+import scala.util.control.NonFatal
+import typer.ProtoTypes.constrained
+import typer.Applications.productSelectorTypes
+import reporting.trace
+import annotation.constructorOnly
+import cc.*
+import Capabilities.Capability
+import NameKinds.WildcardParamName
+import MatchTypes.isConcrete
+import reporting.Message.Note
+import scala.util.boundary, boundary.break
+
 object MatchReducer:
   import printing.*, Texts.*
   enum MatchResult extends Showable:
@@ -15,8 +46,6 @@ object MatchReducer:
       case NoInstance(fails)  => "NoInstance(" ~ Text(fails.map(p.toText(_) ~ p.toText(_)), ", ") ~ ")"
 
 /** A type comparer for reducing match types.
- *  TODO: Not sure this needs to be a type comparer. Can we make it a
- *  separate class?
  */
 class MatchReducer(initctx: Context) extends TypeComparer(initctx) {
   import MatchReducer.*