Stub implementation of xml interpolator

Author: allanrenucci

compiler/test/dotc/run-test-pickling.blacklist

@@ -83,3 +83,4 @@ typelevel-patmat.scala
 typelevel.scala
 typelevel1.scala
 typelevel3.scala
+xml-interpolation

tests/run/xml-interpolation/Test_2.scala

@@ -0,0 +1,8 @@
+import XmlQuote._
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val name = new Object{}
+    assert(xml"Hello $name!" == Xml("Hello !", name))
+  }
+}

tests/run/xml-interpolation/XmlQuote_1.scala

@@ -0,0 +1,52 @@
+import scala.quoted._
+import scala.tasty.Tasty
+
+case class Xml(parts: String, arg: Any)
+
+class XmlQuote(ctx: StringContext) {
+  rewrite def xml(args: => Any*): Xml = ~XmlQuote.impl('(ctx), '(args))
+}
+
+object XmlQuote {
+  implicit rewrite def XmlQuote(ctx: => StringContext): XmlQuote = new XmlQuote(ctx)
+
+  def impl(ctx: Expr[StringContext], args: Expr[Seq[Any]])(implicit tasty: Tasty): Expr[Xml] = {
+    import tasty._
+    import Term._
+
+    // for debugging purpose
+    def pp(tree: Tree): Unit = {
+      println(tasty.showSourceCode.showTree(tree))
+    }
+
+    def isStringConstant(tree: Term) = tree match {
+      case Literal(_) => true
+      case _ => false
+    }
+
+    // _root_.scala.StringContext.apply(("p0", "p1": scala.<repeated>[scala#Predef.String]))
+    val parts = ctx.toTasty match {
+      case Inlined(_, _,
+        Apply(
+          Select(Select(Select(Ident("_root_"), "scala", _), "StringContext", _), "apply", _),
+          List(Typed(Repeated(values), _)))) if values.forall(isStringConstant) =>
+      values.collect { case Literal(Constant.String(value)) => value }
+    case _ =>
+      ???
+    }
+
+    // (a0, a1: scala.<repeated>[scala.Any])
+    val args0: List[Term] = args.toTasty match {
+      case Inlined(_, _, Typed(Repeated(values), _)) =>
+        values
+      case _ =>
+        ???
+    }
+
+    val string = parts.mkString
+    // first one for test purpose
+    val arg0 = args0.head.toExpr[Any]
+
+    '(new Xml(~string.toExpr, ~arg0))
+  }
+}