toExprOfTuple method added

Author: anatoliykmetyuk

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

@@ -0,0 +1,30 @@
+package scala.quoted
+
+trait ToExprOfTuple[T] {
+  type Repr <: Tuple
+  def apply(t: T): given QuoteContext => Expr[Repr]
+}
+
+object ToExprOfTuple {
+  type Aux[T, R <: Tuple] = ToExprOfTuple[T] { type Repr = R }
+}
+
+def (t: T) toExprOfTuple[T] given (tc: ToExprOfTuple[T], ctx: QuoteContext): Expr[tc.Repr] = tc(t)
+
+given [T <: NonEmptyTuple, KA, TEOT <: Tuple] as ToExprOfTuple.Aux[T, KA *: TEOT] given (
+    eqv: Tuple.Head[T] =:= Expr[KA],
+    teot: ToExprOfTuple.Aux[Tuple.Tail[T], TEOT],
+    tph: Type[KA],
+    tpt: Type[TEOT]) = new ToExprOfTuple[T] {
+  type Repr = KA *: TEOT
+  def apply(t: T): given QuoteContext => Expr[Repr] = {
+    val hd: Expr[KA] = eqv(t.head)
+    val tl: Expr[TEOT] = teot(t.tail)
+    '{$hd *: $tl}
+  }
+}
+
+given as ToExprOfTuple[Unit] {
+  type Repr = Unit
+  def apply(t: Unit) = Expr.unitExpr
+}

library/src/scala/quoted/package.scala

@@ -80,8 +80,6 @@ package object quoted {
      */
     def (list: List[Expr[T]]) toExprOfList[T] given Type[T], QuoteContext: Expr[List[T]] =
       if (list.isEmpty) '{ Nil } else '{ List(${list.toExprOfSeq}: _*) }
-
-
   }
 
 }

tests/neg/toexproftuple.scala

@@ -0,0 +1,8 @@
+import scala.quoted._, scala.deriving._
+import given scala.quoted._
+
+inline def mcr: Any = ${mcrImpl}
+def mcrImpl given (ctx: QuoteContext): Expr[Any] = {
+  val tpl: (Expr[1], Expr[2], Expr[3]) = ('{1}, '{2}, '{3})
+  '{val res: (1, 3, 3) = ${tpl.toExprOfTuple}; res}  // error
+}

tests/pos/toexproftuple.scala

@@ -0,0 +1,8 @@
+import scala.quoted._, scala.deriving._
+import given scala.quoted._
+
+inline def mcr: Any = ${mcrImpl}
+def mcrImpl given (ctx: QuoteContext): Expr[Any] = {
+  val tpl: (Expr[1], Expr[2], Expr[3]) = ('{1}, '{2}, '{3})
+  '{val res: (1, 2, 3) = ${tpl.toExprOfTuple}; res}
+}