Upgrade implicits in Interpreter

* Use `using` for `Env` parameters and arguments
* Remove unnecessary `Env` parameters

Author: nicolasstucki

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

@@ -35,14 +35,17 @@ abstract class Interpreter(pos: SrcPos, classLoader: ClassLoader)(using Context)
   import Interpreter._
   import tpd._
 
+  /** Local variable environment */
   type Env = Map[Symbol, Object]
+  def emptyEnv: Env = Map.empty
+  inline def env(using e: Env): e.type = e
 
   /** Returns the result of interpreting the code in the tree.
    *  Return Some of the result or None if the result type is not consistent with the expected type.
    *  Throws a StopInterpretation if the tree could not be interpreted or a runtime exception ocurred.
    */
-  final def interpret[T](tree: Tree)(implicit ct: ClassTag[T]): Option[T] =
-    interpretTree(tree)(Map.empty) match {
+  final def interpret[T](tree: Tree)(using ct: ClassTag[T]): Option[T] =
+    interpretTree(tree)(using emptyEnv) match {
       case obj: T => Some(obj)
       case obj =>
         // TODO upgrade to a full type tag check or something similar
@@ -53,7 +56,7 @@ abstract class Interpreter(pos: SrcPos, classLoader: ClassLoader)(using Context)
   /** Returns the result of interpreting the code in the tree.
    *  Throws a StopInterpretation if the tree could not be interpreted or a runtime exception ocurred.
    */
-  protected def interpretTree(tree: Tree)(implicit env: Env): Object = tree match {
+  protected def interpretTree(tree: Tree)(using Env): Object = tree match {
     case Literal(Constant(value)) =>
       interpretLiteral(value)
 
@@ -135,26 +138,26 @@ abstract class Interpreter(pos: SrcPos, classLoader: ClassLoader)(using Context)
         Nil
   }
 
-  private def interpretBlock(stats: List[Tree], expr: Tree)(implicit env: Env) = {
+  private def interpretBlock(stats: List[Tree], expr: Tree)(using Env) = {
     var unexpected: Option[Object] = None
-    val newEnv = stats.foldLeft(env)((accEnv, stat) => stat match {
+    val newEnv = stats.foldLeft(env)((accEnv, stat) => stat match
       case stat: ValDef =>
-        accEnv.updated(stat.symbol, interpretTree(stat.rhs)(accEnv))
+        accEnv.updated(stat.symbol, interpretTree(stat.rhs)(using accEnv))
       case stat =>
         if (unexpected.isEmpty)
           unexpected = Some(unexpectedTree(stat))
         accEnv
-    })
-    unexpected.getOrElse(interpretTree(expr)(newEnv))
+    )
+    unexpected.getOrElse(interpretTree(expr)(using newEnv))
   }
 
-  private def interpretLiteral(value: Any)(implicit env: Env): Object =
+  private def interpretLiteral(value: Any): Object =
     value.asInstanceOf[Object]
 
-  private def interpretVarargs(args: List[Object])(implicit env: Env): Object =
+  private def interpretVarargs(args: List[Object]): Object =
     args.toSeq
 
-  private def interpretedStaticMethodCall(moduleClass: Symbol, fn: Symbol)(implicit env: Env): List[Object] => Object = {
+  private def interpretedStaticMethodCall(moduleClass: Symbol, fn: Symbol): List[Object] => Object = {
     val (inst, clazz) =
       try
         if (moduleClass.name.startsWith(str.REPL_SESSION_LINE))
@@ -174,22 +177,22 @@ abstract class Interpreter(pos: SrcPos, classLoader: ClassLoader)(using Context)
     (args: List[Object]) => stopIfRuntimeException(method.invoke(inst, args: _*), method)
   }
 
-  private def interpretedStaticFieldAccess(sym: Symbol)(implicit env: Env): Object = {
+  private def interpretedStaticFieldAccess(sym: Symbol): Object = {
     val clazz = loadClass(sym.owner.fullName.toString)
     val field = clazz.getField(sym.name.toString)
     field.get(null)
   }
 
-  private def interpretModuleAccess(fn: Symbol)(implicit env: Env): Object =
+  private def interpretModuleAccess(fn: Symbol): Object =
     loadModule(fn.moduleClass)
 
-  private def interpretNew(fn: Symbol, args: => List[Object])(implicit env: Env): Object = {
+  private def interpretNew(fn: Symbol, args: => List[Object]): Object = {
     val clazz = loadClass(fn.owner.fullName.toString)
     val constr = clazz.getConstructor(paramsSig(fn): _*)
     constr.newInstance(args: _*).asInstanceOf[Object]
   }
 
-  private def unexpectedTree(tree: Tree)(implicit env: Env): Object =
+  private def unexpectedTree(tree: Tree): Object =
     throw new StopInterpretation("Unexpected tree could not be interpreted: " + tree, tree.srcPos)
 
   private def loadModule(sym: Symbol): Object =
@@ -209,7 +212,7 @@ abstract class Interpreter(pos: SrcPos, classLoader: ClassLoader)(using Context)
       clazz.getConstructor().newInstance().asInstanceOf[Object]
     }
 
-  private def loadReplLineClass(moduleClass: Symbol)(implicit env: Env): Class[?] = {
+  private def loadReplLineClass(moduleClass: Symbol): Class[?] = {
     val lineClassloader = new AbstractFileClassLoader(ctx.settings.outputDir.value, classLoader)
     lineClassloader.loadClass(moduleClass.name.firstPart.toString)
   }