Add comments to RawQuotes

Author: nicolasstucki

compiler/src/dotty/tools/dotc/interpreter/RawExpr.scala

@@ -2,6 +2,5 @@ package dotty.tools.dotc.interpreter
 
 import dotty.tools.dotc.ast.tpd
 
-class RawExpr(val tree: tpd.Tree) extends quoted.Expr[Any] with RawQuoted {
-  override def toString: String = s"RawExpr(${tree.toString})"
-}
+/** Expression `quoted.Expr[_]` for which its internal representation is its tree. */
+final class RawExpr(val tree: tpd.Tree) extends quoted.Expr[Any] with RawQuoted

compiler/src/dotty/tools/dotc/interpreter/RawQuoted.scala

@@ -2,6 +2,11 @@ package dotty.tools.dotc.interpreter
 
 import dotty.tools.dotc.ast.tpd
 
+/** Quoted `quoted.Quoted` for which its internal representation is its tree.
+ *  - Used for trees that cannot be serialized, such as references to local symbols that will be spliced in.
+ *  - Used for trees that do not need to be serialized to avoid the overhead of serialization/deserialization.
+ */
 trait RawQuoted extends quoted.Quoted {
   def tree: tpd.Tree
+  override def toString: String = s"${this.getClass.getName}(${tree.toString})"
 }

compiler/src/dotty/tools/dotc/interpreter/RawType.scala

@@ -2,6 +2,5 @@ package dotty.tools.dotc.interpreter
 
 import dotty.tools.dotc.ast.tpd
 
-class RawType(val tree: tpd.Tree) extends quoted.Type[Any] with RawQuoted {
-  override def toString: String = s"RawType(${tree.toString})"
-}
+/** Type `quoted.Type[_]` for which its internal representation is its type tree. */
+final class RawType(val tree: tpd.Tree) extends quoted.Type[Any] with RawQuoted