scarpet corountines idea

src/main/java/carpet/script/Context.java

@@ -1,6 +1,7 @@
 package carpet.script;
 
 import carpet.script.exception.InternalExpressionException;
+import carpet.script.value.ThreadValue;
 import carpet.script.value.Value;
 
 import java.util.HashMap;
@@ -30,6 +31,8 @@ public class Context
 
     public final ScriptHost host;
 
+    private ThreadValue threadContext = null;
+
     public Context(ScriptHost host)
     {
         this.host = host;
@@ -69,10 +72,21 @@ public class Context
     public Context recreate()
     {
         Context ctx = duplicate();
+        ctx.threadContext = threadContext;
         ctx.initialize();
         return ctx;
     }
 
+    public void setThreadContext(ThreadValue callingThread)
+    {
+        this.threadContext = callingThread;
+    }
+
+    public ThreadValue getThreadContext()
+    {
+        return threadContext;
+    }
+
     protected void initialize()
     {
         //special variables for second order functions so we don't need to check them all the time