Merge pull request #6885 from dotty-staging/move-refect-utils-into-TreeUtils

Integrate Reflection.utils into TreeUtils

Author: liufengyun

library/src/scala/tasty/Reflection.scala

@@ -40,9 +40,4 @@ class Reflection(val kernel: Kernel)
     def typeChecks(code: String)(implicit ctx: Context): Boolean = kernel.typeChecks(code)(ctx)
   }
 
-  // TODO integrate with TreeUtils
-  val util: reflect.utils.TreeUtils { val reflect: self.type } = new reflect.utils.TreeUtils {
-    val reflect: self.type = self
-  }
-
 }

library/src/scala/tasty/reflect/TreeUtils.scala

@@ -6,7 +6,7 @@ trait TreeUtils
     extends Core
     with PatternOps
     with SymbolOps
-    with TreeOps {
+    with TreeOps { self: Reflection =>
 
   abstract class TreeAccumulator[X] {
 
@@ -283,4 +283,29 @@ trait TreeUtils
 
   }
 
+  /** Bind the `rhs` to a `val` and use it in `body` */
+  def let(rhs: Term)(body: Ident => Term): Term = {
+    import scala.quoted.QuoteContext
+    delegate for QuoteContext = new QuoteContext(this)
+    type T // TODO probably it is better to use the Sealed contruct rather than let the user create their own existential type
+    implicit val rhsTpe: quoted.Type[T] = rhs.tpe.seal.asInstanceOf[quoted.Type[T]]
+    val rhsExpr = rhs.seal.cast[T]
+    val expr = '{
+      val x = $rhsExpr
+      ${
+        val id = ('x).unseal.asInstanceOf[Ident]
+        body(id).seal
+      }
+    }
+    expr.unseal
+  }
+
+  /** Bind the given `terms` to names and use them in the `body` */
+  def lets(terms: List[Term])(body: List[Term] => Term): Term = {
+    def rec(xs: List[Term], acc: List[Term]): Term = xs match {
+      case Nil => body(acc)
+      case x :: xs => let(x) { (x: Term) => rec(xs, x :: acc) }
+    }
+    rec(terms, Nil)
+  }
 }

library/src/scala/tasty/reflect/utils/TreeUtils.scala

@@ -10,7 +10,7 @@ object Macros {
 
     val rhsTerm = rhs.unseal
 
-    import qctx.tasty.util.{let => letTerm}
+    import qctx.tasty.{let => letTerm}
     letTerm(rhsTerm) { rhsId =>
       body(rhsId.seal.asInstanceOf[Expr[T]]).unseal // Dangerous uncheked cast!
     }.seal.cast[Unit]