Implement extractor for quoted trees

Author: nicolasstucki

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

@@ -8,7 +8,7 @@ import dotty.tools.dotc.core.Contexts._
 import dotty.tools.dotc.core.Flags._
 import dotty.tools.dotc.core.Decorators._
 import dotty.tools.dotc.core.Symbols._
-
+import dotty.tools.dotc.quoted.Quoted
 import scala.reflect.ClassTag
 import java.net.URLClassLoader
 
@@ -53,13 +53,9 @@ class Interpreter(implicit ctx: Context) {
   private def interpretTreeImpl(tree: Tree): Object = {
     try {
       tree match {
-        case Apply(_, quote :: Nil) if tree.symbol eq defn.quoteMethod =>
-          RawQuoted(quote)
-        case TypeApply(_, quote :: Nil) if tree.symbol eq defn.typeQuoteMethod =>
-          RawQuoted(quote)
+        case Quoted(quotedTree) => RawQuoted(quotedTree)
 
-        case Literal(Constant(c)) =>
-          c.asInstanceOf[AnyRef]
+        case Literal(Constant(c)) => c.asInstanceOf[AnyRef]
 
         case Apply(fn, args) if fn.symbol.isConstructor =>
           val cls = fn.symbol.owner

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

@@ -0,0 +1,20 @@
+package dotty.tools.dotc.quoted
+
+import dotty.tools.dotc.ast.Trees.GenericApply
+import dotty.tools.dotc.ast.tpd
+import dotty.tools.dotc.core.Contexts.Context
+import dotty.tools.dotc.core.Types.Type
+import dotty.tools.dotc.transform.SymUtils._
+
+/** Extractors for quotes */
+object Quoted {
+
+  /** Extracts the content of a quoted tree.
+   *  The result can be the contents of a term ot type quote, which
+   *  will return a term or type tree respectively.
+   */
+  def unapply(tree: tpd.Tree)(implicit ctx: Context): Option[tpd.Tree] = tree match {
+    case tree: GenericApply[Type] if tree.symbol.isQuote => Some(tree.args.head)
+    case _ => None
+  }
+}

compiler/src/dotty/tools/dotc/transform/ReifyQuotes.scala

@@ -17,6 +17,7 @@ import NameKinds.OuterSelectName
 import scala.collection.mutable
 import dotty.tools.dotc.core.StdNames._
 import dotty.tools.dotc.quoted.PickledQuotes
+import dotty.tools.dotc.quoted.Quoted
 
 
 /** Translates quoted terms and types to `unpickle` method calls.
@@ -316,10 +317,8 @@ class ReifyQuotes extends MacroTransform {
               enteredSyms = enteredSyms.tail
             }
         tree match {
-          case Apply(fn, arg :: Nil) if fn.symbol == defn.quoteMethod =>
-            quotation(arg, tree)
-          case TypeApply(fn, arg :: Nil) if fn.symbol == defn.typeQuoteMethod =>
-             quotation(arg, tree)
+          case Quoted(quotedTree) =>
+            quotation(quotedTree, tree)
           case Select(body, _) if tree.symbol.isSplice =>
             splice(body, tree)
           case Block(stats, _) =>

compiler/src/dotty/tools/dotc/transform/Splicer.scala

@@ -7,6 +7,7 @@ import dotty.tools.dotc.ast.Trees._
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.interpreter._
 import dotty.tools.dotc.quoted.PickledQuotes
+import dotty.tools.dotc.quoted.Quoted
 
 import scala.quoted
 
@@ -19,8 +20,7 @@ object Splicer {
    *  resulting expression is return as a `Tree`
    */
   def splice(tree: Tree)(implicit ctx: Context): Tree = tree match {
-    case Apply(quote, quoted :: Nil) if quote.symbol == defn.quoteMethod => quoted
-    case TypeApply(quote, quoted :: Nil) if quote.symbol == defn.typeQuoteMethod => quoted
+    case Quoted(quotedTree) => quotedTree
     case tree: RefTree => reflectiveSplice(tree)
     case tree: Apply => reflectiveSplice(tree)
     case tree: Inlined => reflectiveSplice(tree)