merged

--- a/src/Pure/System/scala.scala	Sat Apr 09 12:10:17 2022 +0200
+++ b/src/Pure/System/scala.scala	Sat Apr 09 12:35:48 2022 +0200
@@ -112,11 +112,15 @@
         }
       }
 
-      def toplevel(source: String): List[String] = {
+      def toplevel(interpret: Boolean, source: String): List[String] = {
         val out = new StringWriter
         val interp = interpreter(new PrintWriter(out))
         val marker = '\u000b'
-        val ok = interp.withLabel(marker.toString) { (new interp.ReadEvalPrint).compile(source) }
+        val ok =
+          interp.withLabel(marker.toString) {
+            if (interpret) interp.interpret(source) == Results.Success
+            else (new interp.ReadEvalPrint).compile(source)
+          }
         out.close()
 
         val Error = """(?s)^\S* error: (.*)$""".r
@@ -131,9 +135,15 @@
 
   object Toplevel extends Fun_String("scala_toplevel") {
     val here = Scala_Project.here
-    def apply(source: String): String = {
+    def apply(arg: String): String = {
+      val (interpret, source) =
+        YXML.parse_body(arg) match {
+          case Nil => (false, "")
+          case List(XML.Text(source)) => (false, source)
+          case body => import XML.Decode._; pair(bool, string)(body)
+        }
       val errors =
-        try { Compiler.context().toplevel(source) }
+        try { Compiler.context().toplevel(interpret, source) }
         catch { case ERROR(msg) => List(msg) }
       locally { import XML.Encode._; YXML.string_of_body(list(string)(errors)) }
     }

--- a/src/Pure/System/scala_compiler.ML	Sat Apr 09 12:10:17 2022 +0200
+++ b/src/Pure/System/scala_compiler.ML	Sat Apr 09 12:35:48 2022 +0200
@@ -6,7 +6,7 @@
 
 signature SCALA_COMPILER =
 sig
-  val toplevel: string -> unit
+  val toplevel: bool -> string -> unit
   val static_check: string * Position.T -> unit
 end;
 
@@ -15,15 +15,18 @@
 
 (* check declaration *)
 
-fun toplevel source =
+fun toplevel interpret source =
   let val errors =
-    \<^scala>\<open>scala_toplevel\<close> source
+    (interpret, source)
+    |> let open XML.Encode in pair bool string end
+    |> YXML.string_of_body
+    |> \<^scala>\<open>scala_toplevel\<close>
     |> YXML.parse_body
     |> let open XML.Decode in list string end
   in if null errors then () else error (cat_lines errors) end;
 
 fun static_check (source, pos) =
-  toplevel ("package test\nclass __Dummy__ { __dummy__ => " ^ source ^ " }")
+  toplevel false ("package test\nclass __Dummy__ { __dummy__ => " ^ source ^ " }")
     handle ERROR msg => error (msg ^ Position.here pos);