1 files changed, 15 insertions, 6 deletions
diff --git a/lua.go b/lua.go
index 11eec3e..79b5ba3 100644
--- a/lua.go
+++ b/lua.go
@@ -36,6 +36,7 @@ type Lua struct {
 	running **Lua
 	yield func()
 	resume func() bool
+	deferred func()
 }
 
 //export luna_run_go_func
@@ -46,19 +47,26 @@ func luna_run_go_func(f C.uintptr_t) C.int {
 }
 
 // Start opens the Lua context with all built-in libraries.
-func (l *Lua) Start() {
+func (l *Lua) Start() error {
+	if l.l != nil {
+		return errors.New("already started")
+	}
 	l.l = C.luaL_newstate()
 	l.running = &l
+	l.yield = nil
+	l.resume = nil
 	C.luaL_openlibs(l.l)
 
 	// Put traceback function at the start of the stack so it's always
 	// possible to refer to it via stack index 1.
 	l.PushGoFunction(TracebackHandler)
+	return nil
 }
 
 // Close closes the Lua context.
 func (l *Lua) Close() {
 	C.lua_close(l.l)
+	l.l = nil
 }
 
 // PCall calls a function with the stack index (-nargs-1) expecting nresults
@@ -71,8 +79,13 @@ func (l *Lua) PCall(nargs int, nresults int, errfunc int) error {
 	if res != C.LUA_OK {
 		errMsg := l.ToString(-1)
 		l.Pop(1)
+		l.deferred = nil
 		return errors.New(errMsg)
 	}
+	if l.deferred != nil {
+		l.deferred()
+		l.deferred = nil
+	}
 	return nil
 }
 
@@ -271,11 +284,7 @@ func (l *Lua) LoadAndCall(code string) error {
 		l.Pop(1)
 		return errors.New(errMsg)
 	}
-	err := l.PCall(0, C.LUA_MULTRET, 1)
-	if err != nil {
-		return err
-	}
-	return nil
+	return l.PCall(0, C.LUA_MULTRET, 1)
 }
 
 // SetGlobal sets a global value at the -1 stack index with the name.