Fix impure by name macro parameters

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

@@ -45,7 +45,7 @@ object Splicer {
    *  - Other parameters are lifted to quoted.Types.TreeExpr (may reference a binding)
    */
   private def getLiftedArgs(call: Tree, bindings: List[Tree])(implicit ctx: Context): List[Any] = {
-    val bindMap = bindings.map {
+    val bindMap = bindings.collect {
       case vdef: ValDef => (vdef.rhs, ref(vdef.symbol))
     }.toMap
     def allArgs(call: Tree, acc: List[List[Tree]]): List[List[Tree]] = call match {

tests/run/quote-impure-by-name.check

@@ -0,0 +1 @@
+1 + {Index.zero[String("bar"), scala.Tuple2[String("baz"), scala.Unit]]}

tests/run/quote-impure-by-name/quoted_1.scala

@@ -0,0 +1,18 @@
+import scala.quoted._
+
+import dotty.tools.dotc.quoted.Toolbox._
+
+class Index[K, Keys](val index: String) extends AnyVal {
+  override def toString: String = index
+}
+object Index {
+
+  implicit def zero[K, T]: Index[K, (K, T)] = new Index("0")
+
+  implicit inline def succ[K, H, T](implicit prev: => Index[K, T]): Index[K, (H, T)] = ~succImpl('(prev))('[K], '[H], '[T])
+
+  def succImpl[K, H, T](prev: Expr[Index[K, T]])(implicit k: Type[K], h: Type[H], t: Type[T]): Expr[Index[K, (H, T)]] = {
+    val value = s"1 + {${prev.show}}"
+    '(new Index(~value.toExpr))
+  }
+}

tests/run/quote-impure-by-name/quoted_2.scala

@@ -0,0 +1,6 @@
+object Test {
+
+  def main(args: Array[String]): Unit = {
+    println(Index.succ["bar", "foo", ("bar", ("baz", Unit))])
+  }
+}

tests/run/quote-indexed-map-by-name/quoted_1.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+class Index[K, Keys](val index: Int) extends AnyVal
+object Index {
+
+  implicit def zero[K, T]: Index[K, (K, T)] = new Index(0)
+
+  implicit inline def succ[K, H, T](implicit prev: => Index[K, T]): Index[K, (H, T)] = ~succImpl('[K], '[H], '[T])
+
+  def succImpl[K, H, T](implicit k: Type[K], h: Type[H], t: Type[T]): Expr[Index[K, (H, T)]] = {
+    '(new Index(0))
+  }
+}

tests/run/quote-indexed-map-by-name/quoted_2.scala

@@ -0,0 +1,6 @@
+object Test {
+
+  def main(args: Array[String]): Unit = {
+    Index.succ["bar", "foo", ("bar", ("baz", Unit))]
+  }
+}