Merge pull request #10269 from dotty-staging/define-expr-methods-in-quote-context

Define Expr methods in QuoteContext

Author: nicolasstucki

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

@@ -20,10 +20,6 @@ final class ExprImpl(val tree: tpd.Tree, val scopeId: Int) extends scala.quoted.
     case _ => false
   }
 
-  def unseal(using qctx: QuoteContext): qctx.reflect.Term =
-    checkScopeId(qctx.hashCode)
-    tree.asInstanceOf[qctx.reflect.Term]
-
   def checkScopeId(expectedScopeId: Int): Unit =
     if expectedScopeId != scopeId then
       throw new ScopeException("Cannot call `scala.quoted.staging.run(...)` within a macro or another `run(...)`")

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

@@ -43,6 +43,42 @@ object QuoteContextImpl {
 
 class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickler, QuoteMatching:
 
+  extension [T](self: scala.quoted.Expr[T]):
+    def show: String =
+      reflect.TreeMethodsImpl.show(self.asReflectTree)
+
+    def showAnsiColored: String =
+      reflect.TreeMethodsImpl.showAnsiColored(self.asReflectTree)
+
+    def matches(that: scala.quoted.Expr[Any]): Boolean =
+      treeMatch(self.asReflectTree, that.asReflectTree).nonEmpty
+
+    def asReflectTree: reflect.Term =
+      val expr = self.asInstanceOf[ExprImpl]
+      expr.checkScopeId(QuoteContextImpl.this.hashCode)
+      expr.tree
+
+  end extension
+
+  extension [X](self: scala.quoted.Expr[Any]):
+    /** Checks is the `quoted.Expr[?]` is valid expression of type `X` */
+    def isExprOf(using scala.quoted.Type[X]): Boolean =
+      reflect.TypeReprMethodsImpl.<:<(self.asReflectTree.tpe)(reflect.TypeRepr.of[X])
+
+    /** Convert this to an `quoted.Expr[X]` if this expression is a valid expression of type `X` or throws */
+    def asExprOf(using scala.quoted.Type[X]): scala.quoted.Expr[X] = {
+      if isExprOf[X] then
+        self.asInstanceOf[scala.quoted.Expr[X]]
+      else
+        throw Exception(
+          s"""Expr cast exception: ${self.show}
+            |of type: ${reflect.TypeReprMethodsImpl.show(self.asReflectTree.tpe)}
+            |did not conform to type: ${reflect.TypeReprMethodsImpl.show(reflect.TypeRepr.of[X])}
+            |""".stripMargin
+        )
+    }
+  end extension
+
   object reflect extends scala.tasty.Reflection:
 
     def rootContext: Context = ctx
@@ -72,15 +108,15 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickl
             case _ => false
         def asExpr: scala.quoted.Expr[Any] =
           if self.isExpr then
-            new dotty.tools.dotc.quoted.ExprImpl(self, QuoteContextImpl.this.hashCode)
+            new ExprImpl(self, QuoteContextImpl.this.hashCode)
           else self match
             case TermTypeTest(self) => throw new Exception("Expected an expression. This is a partially applied Term. Try eta-expanding the term first.")
             case _ => throw new Exception("Expected a Term but was: " + self)
       end extension
 
       extension [T](self: Tree)
         def asExprOf(using tp: scala.quoted.Type[T]): scala.quoted.Expr[T] =
-          self.asExpr.asExprOf[T](using tp)(using QuoteContextImpl.this)
+          QuoteContextImpl.this.asExprOf[T](self.asExpr)(using tp)
       end extension
 
     end TreeMethodsImpl
@@ -316,11 +352,11 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickl
     object TermMethodsImpl extends TermMethods:
       extension (self: Term):
         def seal: scala.quoted.Expr[Any] =
-          if self.isExpr then new dotty.tools.dotc.quoted.ExprImpl(self, QuoteContextImpl.this.hashCode)
+          if self.isExpr then new ExprImpl(self, QuoteContextImpl.this.hashCode)
           else throw new Exception("Cannot seal a partially applied Term. Try eta-expanding the term first.")
 
         def sealOpt: Option[scala.quoted.Expr[Any]] =
-          if self.isExpr then Some(new dotty.tools.dotc.quoted.ExprImpl(self, QuoteContextImpl.this.hashCode))
+          if self.isExpr then Some(new ExprImpl(self, QuoteContextImpl.this.hashCode))
           else None
 
         def tpe: TypeRepr = self.tpe
@@ -1003,7 +1039,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickl
 
     object TypeTree extends TypeTreeModule:
       def of[T <: AnyKind](using tp: scala.quoted.Type[T]): TypeTree =
-        tp.asInstanceOf[dotty.tools.dotc.quoted.TypeImpl].typeTree
+        tp.asInstanceOf[TypeImpl].typeTree
     end TypeTree
 
     object TypeTreeMethodsImpl extends TypeTreeMethods:
@@ -1572,7 +1608,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickl
 
     object TypeRepr extends TypeReprModule:
       def of[T <: AnyKind](using tp: scala.quoted.Type[T]): TypeRepr =
-        tp.asInstanceOf[dotty.tools.dotc.quoted.TypeImpl].typeTree.tpe
+        tp.asInstanceOf[TypeImpl].typeTree.tpe
       def typeConstructorOf(clazz: Class[?]): TypeRepr =
         if (clazz.isPrimitive)
           if (clazz == classOf[Boolean]) dotc.core.Symbols.defn.BooleanType
@@ -1609,7 +1645,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickl
         def seal: scala.quoted.Type[_] = self.asType
 
         def asType: scala.quoted.Type[?] =
-          new dotty.tools.dotc.quoted.TypeImpl(Inferred(self), QuoteContextImpl.this.hashCode)
+          new TypeImpl(Inferred(self), QuoteContextImpl.this.hashCode)
 
         def =:=(that: TypeRepr): Boolean = self =:= that
         def <:<(that: TypeRepr): Boolean = self <:< that
@@ -2624,16 +2660,16 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext, QuoteUnpickl
 
   def unpickleExpr[T](pickled: String | List[String], typeHole: (Int, Seq[Any]) => scala.quoted.Type[?], termHole: (Int, Seq[Any], scala.quoted.QuoteContext) => scala.quoted.Expr[?]): scala.quoted.Expr[T] =
     val tree = PickledQuotes.unpickleTerm(pickled, typeHole, termHole)(using reflect.rootContext)
-    new dotty.tools.dotc.quoted.ExprImpl(tree, hash).asInstanceOf[scala.quoted.Expr[T]]
+    new ExprImpl(tree, hash).asInstanceOf[scala.quoted.Expr[T]]
 
   def unpickleType[T <: AnyKind](pickled: String | List[String], typeHole: (Int, Seq[Any]) => scala.quoted.Type[?], termHole: (Int, Seq[Any], scala.quoted.QuoteContext) => scala.quoted.Expr[?]): scala.quoted.Type[T] =
     val tree = PickledQuotes.unpickleTypeTree(pickled, typeHole, termHole)(using reflect.rootContext)
-    new dotty.tools.dotc.quoted.TypeImpl(tree, hash).asInstanceOf[scala.quoted.Type[T]]
+    new TypeImpl(tree, hash).asInstanceOf[scala.quoted.Type[T]]
 
   object ExprMatch extends ExprMatchModule:
     def unapply[TypeBindings <: Tuple, Tup <: Tuple](scrutinee: scala.quoted.Expr[Any])(using pattern: scala.quoted.Expr[Any]): Option[Tup] =
-      val scrutineeTree = scrutinee.unseal(using QuoteContextImpl.this)
-      val patternTree = pattern.unseal(using QuoteContextImpl.this)
+      val scrutineeTree = QuoteContextImpl.this.asReflectTree(scrutinee)
+      val patternTree = QuoteContextImpl.this.asReflectTree(pattern)
       treeMatch(scrutineeTree, patternTree).asInstanceOf[Option[Tup]]
   end ExprMatch
 

library/src-bootstrapped/scala/quoted/Expr.scala

@@ -1,71 +1,10 @@
 package scala.quoted
 
 /** Quoted expression of type `T` */
-abstract class Expr[+T] private[scala] {
-
-  /** Show a source code like representation of this expression without syntax highlight */
-  def show(using qctx: QuoteContext): String = this.unseal.show
-
-  /** Shows the tree as fully typed source code colored with ANSI */
-  def showAnsiColored(using qctx: QuoteContext): String = this.unseal.showAnsiColored
-
-  /** Pattern matches `this` against `that`. Effectively performing a deep equality check.
-   *  It does the equivalent of
-   *  ```
-   *  this match
-   *    case '{...} => true // where the contents of the pattern are the contents of `that`
-   *    case _ => false
-   *  ```
-   */
-  final def matches(that: Expr[Any])(using qctx: QuoteContext): Boolean =
-    val ExprMatch = qctx.asInstanceOf[scala.quoted.internal.QuoteMatching].ExprMatch
-    ExprMatch.unapply[EmptyTuple, EmptyTuple](this)(using that).nonEmpty
-
-  /** Checks is the `quoted.Expr[?]` is valid expression of type `X` */
-  def isExprOf[X](using tp: scala.quoted.Type[X])(using qctx: QuoteContext): Boolean =
-    this.unseal.tpe <:< qctx.reflect.TypeRepr.of[X]
-
-  /** Convert this to an `quoted.Expr[X]` if this expression is a valid expression of type `X` or throws */
-  def asExprOf[X](using tp: scala.quoted.Type[X])(using qctx: QuoteContext): scala.quoted.Expr[X] = {
-    if isExprOf[X] then
-      this.asInstanceOf[scala.quoted.Expr[X]]
-    else
-      throw Exception(
-        s"""Expr cast exception: ${this.show}
-           |of type: ${this.unseal.tpe.show}
-           |did not conform to type: ${qctx.reflect.TypeRepr.of[X].show}
-           |""".stripMargin
-      )
-  }
-
-  /** View this expression `quoted.Expr[T]` as a `Term` */
-  def unseal(using qctx: QuoteContext): qctx.reflect.Term
-
-}
+abstract class Expr[+T] private[scala]
 
 object Expr {
 
-  extension [T](expr: Expr[T]):
-    /** Return the unlifted value of this expression.
-     *
-     *  Returns `None` if the expression does not contain a value or contains side effects.
-     *  Otherwise returns the `Some` of the value.
-     */
-    def unlift(using qctx: QuoteContext, unlift: Unliftable[T]): Option[T] =
-      unlift.fromExpr(expr)
-
-    /** Return the unlifted value of this expression.
-     *
-     *  Emits an error and throws if the expression does not contain a value or contains side effects.
-     *  Otherwise returns the value.
-     */
-    def unliftOrError(using qctx: QuoteContext, unlift: Unliftable[T]): T =
-      def reportError =
-        val msg = s"Expected a known value. \n\nThe value of: ${expr.show}\ncould not be unlifted using $unlift"
-        report.throwError(msg, expr)
-      unlift.fromExpr(expr).getOrElse(reportError)
-  end extension
-
   /** `e.betaReduce` returns an expression that is functionally equivalent to `e`,
    *   however if `e` is of the form `((y1, ..., yn) => e2)(e1, ..., en)`
    *   then it optimizes this the top most call by returning the result of beta-reducing the application.

library/src-non-bootstrapped/scala/quoted/Expr.scala

@@ -1,5 +1,3 @@
 package scala.quoted
 
-abstract class Expr[+T] private[scala]:
-  def unseal(using qctx: QuoteContext): qctx.reflect.Term
-  def asExprOf[X](using tp: scala.quoted.Type[X])(using qctx: QuoteContext): scala.quoted.Expr[X] = ???
+abstract class Expr[+T] private[scala]

library/src-non-bootstrapped/scala/quoted/Unliftable.scala

@@ -0,0 +1,4 @@
+package scala.quoted
+
+trait Unliftable[T]:
+  def fromExpr(x: Expr[T]): QuoteContext ?=> Option[T]

library/src-non-bootstrapped/scala/quoted/report.scala

@@ -10,6 +10,59 @@ package scala.quoted
  */
 trait QuoteContext { self: internal.QuoteUnpickler & internal.QuoteMatching =>
 
+  // Extension methods for `Expr[T]`
+  extension [T](self: Expr[T]):
+    /** Show a source code like representation of this expression without syntax highlight */
+    def show: String
+
+    /** Shows the tree as fully typed source code colored with ANSI */
+    def showAnsiColored: String
+
+    /** Pattern matches `this` against `that`. Effectively performing a deep equality check.
+    *  It does the equivalent of
+    *  ```
+    *  this match
+    *    case '{...} => true // where the contents of the pattern are the contents of `that`
+    *    case _ => false
+    *  ```
+    */
+    def matches(that: Expr[Any]): Boolean
+
+    /** Return the unlifted value of this expression.
+     *
+     *  Returns `None` if the expression does not contain a value or contains side effects.
+     *  Otherwise returns the `Some` of the value.
+     */
+    def unlift(using unlift: Unliftable[T]): Option[T] =
+      unlift.fromExpr(self)(using QuoteContext.this)
+
+    /** Return the unlifted value of this expression.
+     *
+     *  Emits an error and throws if the expression does not contain a value or contains side effects.
+     *  Otherwise returns the value.
+     */
+    def unliftOrError(using unlift: Unliftable[T]): T =
+      def reportError =
+        val msg = s"Expected a known value. \n\nThe value of: ${self.show}\ncould not be unlifted using $unlift"
+        report.throwError(msg, self)(using QuoteContext.this)
+      unlift.fromExpr(self)(using QuoteContext.this).getOrElse(reportError)
+
+    /** View this expression `quoted.Expr[T]` as a `Term` */
+    def unseal: reflect.Term = self.asReflectTree // TODO remove
+
+    /** View this expression `quoted.Expr[T]` as a `Term` */
+    def asReflectTree: reflect.Term
+  end extension
+
+  // Extension methods for `Expr[Any]` that take another explicit type parameter
+  extension [X](self: Expr[Any]):
+    /** Checks is the `quoted.Expr[?]` is valid expression of type `X` */
+    def isExprOf(using tp: scala.quoted.Type[X]): Boolean
+
+    /** Convert this to an `quoted.Expr[X]` if this expression is a valid expression of type `X` or throws */
+    def asExprOf(using tp: scala.quoted.Type[X]): scala.quoted.Expr[X]
+  end extension
+
   /** Low-level Typed AST API metaprogramming API.
    *  This API does not have the static type guarantiees that `Expr` and `Type` provide.
    */

library/src/scala/quoted/QuoteContext.scala

@@ -1,14 +1,12 @@
 import scala.quoted._
 
-object Macros {
-
-  implicit inline def identityMaped[T](x: => T): T = ${ impl('x) }
+object Macros:
+  implicit inline def identityMaped[T](x: => T): T = ${ MacrosImpl.impl('x) }
 
+object MacrosImpl:
   def impl[T: Type](x: Expr[T])(using qctx: QuoteContext) : Expr[T] = {
-    import qctx.reflect.{_, given} // FIXME: #8919
+    import qctx.reflect._
     val identityMap = new TreeMap { }
     val transformed = identityMap.transformTerm(x.unseal).asExprOf[T]
     transformed
   }
-
-}