Drop (using ...) closures in compiler codebase

Author: odersky

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

@@ -124,7 +124,7 @@ object Annotations {
   object LazyBodyAnnotation {
     def apply(bodyFn: Context ?=> Tree): LazyBodyAnnotation =
       new LazyBodyAnnotation:
-        protected var myTree: Tree | (Context ?=> Tree) = (using ctx) => bodyFn(using ctx)
+        protected var myTree: Tree | (Context ?=> Tree) = ctx ?=> bodyFn(using ctx)
   }
 
   object Annotation {
@@ -155,15 +155,15 @@ object Annotations {
     /** Create an annotation where the tree is computed lazily. */
     def deferred(sym: Symbol)(treeFn: Context ?=> Tree)(using Context): Annotation =
       new LazyAnnotation {
-        protected var myTree: Tree | (Context ?=> Tree) = (using ctx) => treeFn(using ctx)
+        protected var myTree: Tree | (Context ?=> Tree) = ctx ?=> treeFn(using ctx)
         protected var mySym: Symbol | (Context ?=> Symbol) = sym
       }
 
     /** Create an annotation where the symbol and the tree are computed lazily. */
     def deferredSymAndTree(symFn: Context ?=> Symbol)(treeFn: Context ?=> Tree)(using Context): Annotation =
       new LazyAnnotation {
-        protected var mySym: Symbol | (Context ?=> Symbol) = (using ctx) => symFn(using ctx)
-        protected var myTree: Tree | (Context ?=> Tree) = (using ctx) => treeFn(using ctx)
+        protected var mySym: Symbol | (Context ?=> Symbol) = ctx ?=> symFn(using ctx)
+        protected var myTree: Tree | (Context ?=> Tree) = ctx ?=> treeFn(using ctx)
       }
 
     /** Extractor for child annotations */

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

@@ -2506,7 +2506,7 @@ object SymDenotations {
   }
 
   object LazyType:
-    private val NoSymbolFn = (using _: Context) => NoSymbol
+    private val NoSymbolFn = (_: Context) ?=> NoSymbol
 
   /** A subtrait of LazyTypes where completerTypeParams yields a List[TypeSymbol], which
    *  should be completed independently of the info.

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

@@ -5148,7 +5148,7 @@ object Types {
           derivedSuperType(tp, this(thistp), this(supertp))
 
         case tp: LazyRef =>
-          LazyRef { (using refCtx) =>
+          LazyRef { refCtx ?=>
             val ref1 = tp.ref
             if refCtx.runId == mapCtx.runId then this(ref1)
             else // splice in new run into map context

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

@@ -587,10 +587,10 @@ class ClassfileParser(
       }
 
     protected var mySym: Symbol | (Context ?=> Symbol) =
-      (using ctx: Context) => annotType.classSymbol
+      (ctx: Context) ?=> annotType.classSymbol
 
     protected var myTree: Tree | (Context ?=> Tree) =
-      (using ctx: Context) => untpd.resolveConstructor(annotType, args)
+      (ctx: Context) ?=> untpd.resolveConstructor(annotType, args)
 
     def untpdTree(using Context): untpd.Tree =
       untpd.New(untpd.TypeTree(annotType), List(args))

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

@@ -603,7 +603,7 @@ class TreeUnpickler(reader: TastyReader,
         forkAt(templateStart).indexTemplateParams()(using localContext(sym))
       }
       else if (sym.isInlineMethod)
-        sym.addAnnotation(LazyBodyAnnotation { (using ctx0: Context) =>
+        sym.addAnnotation(LazyBodyAnnotation { (ctx0: Context) ?=>
           val ctx1 = localContext(sym)(using ctx0).addMode(Mode.ReadPositions)
           inContext(sourceChangeContext(Addr(0))(using ctx1)) {
             // avoids space leaks by not capturing the current context

compiler/src/dotty/tools/dotc/quoted/PickledQuotes.scala

@@ -74,7 +74,7 @@ object PickledQuotes {
       override def transform(tree: tpd.Tree)(using Context): tpd.Tree = tree match {
         case Hole(isTerm, idx, args) =>
           val reifiedArgs = args.map { arg =>
-            if (arg.isTerm) (using q: Quotes) => new ExprImpl(arg, QuotesImpl.scopeId)
+            if (arg.isTerm) (q: Quotes) ?=> new ExprImpl(arg, QuotesImpl.scopeId)
             else new TypeImpl(arg, QuotesImpl.scopeId)
           }
           if isTerm then

compiler/src/dotty/tools/dotc/typer/Implicits.scala

@@ -249,7 +249,7 @@ object Implicits:
       else
         val candidates = new mutable.ListBuffer[Candidate]
         def tryCandidate(extensionOnly: Boolean)(ref: ImplicitRef) =
-          var ckind = exploreInFreshCtx { (using ctx: FreshContext) =>
+          var ckind = exploreInFreshCtx { (ctx: FreshContext) ?=>
             ctx.setMode(ctx.mode | Mode.TypevarsMissContext)
             candidateKind(ref.underlyingRef)
           }