initial Kodkod.warmup: preloading and basic integrity test;

--- a/src/HOL/Tools/Nitpick/kodkod.scala	Thu Aug 27 17:05:59 2020 +0200
+++ b/src/HOL/Tools/Nitpick/kodkod.scala	Thu Aug 27 17:15:33 2020 +0200
@@ -133,11 +133,19 @@
     context.result()
   }
 
+
+  /** protocol handler **/
+
   def warmup(): String =
     execute(
       "solver: \"MiniSat\"\n" +
       File.read(Path.explode("$KODKODI/examples/weber3.kki"))).check
 
+  class Handler extends Session.Protocol_Handler
+  {
+    override def init(session: Session): Unit = warmup()
+  }
+
 
 
   /** scala function **/

--- a/src/HOL/Tools/etc/settings	Thu Aug 27 17:05:59 2020 +0200
+++ b/src/HOL/Tools/etc/settings	Thu Aug 27 17:15:33 2020 +0200
@@ -1,3 +1,4 @@
 # -*- shell-script -*- :mode=shellscript:
 
+isabelle_scala_service 'isabelle.nitpick.Kodkod$Handler'
 isabelle_scala_service 'isabelle.nitpick.Scala_Functions'