--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/System/scala.scala Wed May 20 20:45:43 2020 +0200
@@ -0,0 +1,130 @@
+/* Title: Pure/System/scala.scala
+ Author: Makarius
+
+Support for Scala at runtime.
+*/
+
+package isabelle
+
+
+import java.lang.reflect.{Method, Modifier, InvocationTargetException}
+
+import scala.util.matching.Regex
+
+
+object Scala
+{
+ /** invoke JVM method via Isabelle/Scala **/
+
+ /* method reflection */
+
+ private val Ext = new Regex("(.*)\\.([^.]*)")
+ private val STRING = Class.forName("java.lang.String")
+
+ private def get_method(name: String): String => String =
+ name match {
+ case Ext(class_name, method_name) =>
+ val m =
+ try { Class.forName(class_name).getMethod(method_name, STRING) }
+ catch {
+ case _: ClassNotFoundException | _: NoSuchMethodException =>
+ error("No such method: " + quote(name))
+ }
+ if (!Modifier.isStatic(m.getModifiers)) error("Not at static method: " + m.toString)
+ if (m.getReturnType != STRING) error("Bad method return type: " + m.toString)
+
+ (arg: String) => {
+ try { m.invoke(null, arg).asInstanceOf[String] }
+ catch {
+ case e: InvocationTargetException if e.getCause != null =>
+ throw e.getCause
+ }
+ }
+ case _ => error("Malformed method name: " + quote(name))
+ }
+
+
+ /* method invocation */
+
+ object Tag extends Enumeration
+ {
+ val NULL, OK, ERROR, FAIL, INTERRUPT = Value
+ }
+
+ def method(name: String, arg: String): (Tag.Value, String) =
+ Exn.capture { get_method(name) } match {
+ case Exn.Res(f) =>
+ Exn.capture { f(arg) } match {
+ case Exn.Res(null) => (Tag.NULL, "")
+ case Exn.Res(res) => (Tag.OK, res)
+ case Exn.Exn(Exn.Interrupt()) => (Tag.INTERRUPT, "")
+ case Exn.Exn(e) => (Tag.ERROR, Exn.message(e))
+ }
+ case Exn.Exn(e) => (Tag.FAIL, Exn.message(e))
+ }
+}
+
+
+/* protocol handler */
+
+class Scala extends Session.Protocol_Handler
+{
+ private var session: Session = null
+ private var futures = Map.empty[String, Future[Unit]]
+
+ override def init(init_session: Session): Unit =
+ synchronized { session = init_session }
+
+ override def exit(): Unit = synchronized
+ {
+ for ((id, future) <- futures) cancel(id, future)
+ futures = Map.empty
+ }
+
+ private def fulfill(id: String, tag: Scala.Tag.Value, res: String): Unit =
+ synchronized
+ {
+ if (futures.isDefinedAt(id)) {
+ session.protocol_command("Scala.fulfill", id, tag.id.toString, res)
+ futures -= id
+ }
+ }
+
+ private def cancel(id: String, future: Future[Unit])
+ {
+ future.cancel
+ fulfill(id, Scala.Tag.INTERRUPT, "")
+ }
+
+ private def invoke_scala(msg: Prover.Protocol_Output): Boolean = synchronized
+ {
+ msg.properties match {
+ case Markup.Invoke_Scala(name, id) =>
+ futures += (id ->
+ Future.fork {
+ val (tag, result) = Scala.method(name, msg.text)
+ fulfill(id, tag, result)
+ })
+ true
+ case _ => false
+ }
+ }
+
+ private def cancel_scala(msg: Prover.Protocol_Output): Boolean = synchronized
+ {
+ msg.properties match {
+ case Markup.Cancel_Scala(id) =>
+ futures.get(id) match {
+ case Some(future) => cancel(id, future)
+ case None =>
+ }
+ true
+ case _ => false
+ }
+ }
+
+ val functions =
+ List(
+ Markup.Invoke_Scala.name -> invoke_scala,
+ Markup.Cancel_Scala.name -> cancel_scala)
+}