* Simplify JSR-223 implementation.

* Add in Compilable interface (and use in all cases).
* Add in Invocable interface for creating Java interfaces
  from JS implementations.

src/main/java/org/dynjs/jsr223/DynJSCompiledScript.java

@@ -0,0 +1,39 @@
+package org.dynjs.jsr223;
+
+import org.dynjs.Config;
+import org.dynjs.runtime.DynJS;
+import org.dynjs.runtime.JSProgram;
+import org.dynjs.runtime.Types;
+import org.dynjs.runtime.builtins.DynJSBuiltin;
+
+import javax.script.CompiledScript;
+import javax.script.ScriptContext;
+import javax.script.ScriptEngine;
+import javax.script.ScriptException;
+
+/**
+ * @author Bob McWhirter
+ */
+public class DynJSCompiledScript extends CompiledScript {
+
+    private final DynJSScriptEngine engine;
+    private final JSProgram program;
+
+    DynJSCompiledScript(DynJSScriptEngine engine, JSProgram program) {
+        this.engine = engine;
+        this.program = program;
+    }
+
+    @Override
+    public Object eval(ScriptContext context) throws ScriptException {
+        ScriptEngineGlobalObject global = RuntimeHelper.getGlobalObject( context );
+        DynJS runtime = RuntimeHelper.getRuntime( global, context );
+        return runtime.newRunner().withSource( this.program ).execute();
+    }
+
+    @Override
+    public ScriptEngine getEngine() {
+        return this.engine;
+    }
+
+}