package bait import ( "hilbish/util" rt "github.com/arnodel/golua/runtime" "github.com/arnodel/golua/lib/packagelib" ) type listenerType int const ( goListener listenerType = iota luaListener ) type Recoverer func(event string, handler, err interface{}) type Listener struct{ typ listenerType caller func(...interface{}) luaCaller *rt.Closure } type Bait struct{ Loader packagelib.Loader recoverer Recoverer handlers map[string][]*Listener rtm *rt.Runtime } func New(rtm *rt.Runtime) Bait { b := Bait{ handlers: make(map[string][]*Listener), rtm: rtm, } b.Loader = packagelib.Loader{ Load: b.loaderFunc, Name: "bait", } return b } func (b *Bait) Emit(event string, args ...interface{}) { handles := b.handlers[event] if handles == nil { return } for _, handle := range handles { defer func() { if err := recover(); err != nil { b.callRecoverer(event, handle, err) } }() if handle.typ == luaListener { funcVal := rt.FunctionValue(handle.luaCaller) var luaArgs []rt.Value for _, arg := range args { var luarg rt.Value switch arg.(type) { case rt.Value: luarg = arg.(rt.Value) default: luarg = rt.AsValue(arg) } luaArgs = append(luaArgs, luarg) } _, err := rt.Call1(b.rtm.MainThread(), funcVal, luaArgs...) if err != nil { // panicking here won't actually cause hilbish to panic and instead will // print the error and remove the hook. reference the recoverer function in lua.go panic(err) } } else { handle.caller(args...) } } } func (b *Bait) On(event string, handler func(...interface{})) *Listener { listener := &Listener{ typ: goListener, caller: handler, } b.addListener(event, listener) return listener } func (b *Bait) OnLua(event string, handler *rt.Closure) *Listener { listener :=&Listener{ typ: luaListener, luaCaller: handler, } b.addListener(event, listener) return listener } func (b *Bait) SetRecoverer(recoverer Recoverer) { b.recoverer = recoverer } func (b *Bait) addListener(event string, listener *Listener) { if b.handlers[event] == nil { b.handlers[event] = []*Listener{} } b.handlers[event] = append(b.handlers[event], listener) } func (b *Bait) callRecoverer(event string, handler, err interface{}) { if b.recoverer == nil { panic(err) } b.recoverer(event, handler, err) } func (b *Bait) loaderFunc(rtm *rt.Runtime) (rt.Value, func()) { exports := map[string]util.LuaExport{ "catch": util.LuaExport{b.bcatch, 2, false}, "catchOnce": util.LuaExport{b.bcatchOnce, 2, false}, "throw": util.LuaExport{b.bthrow, 1, true}, } mod := rt.NewTable() util.SetExports(rtm, mod, exports) util.Document(mod, `Bait is the event emitter for Hilbish. Why name it bait? Because it throws hooks that you can catch (emits events that you can listen to) and because why not, fun naming is fun. This is what you will use if you want to listen in on hooks to know when certain things have happened, like when you've changed directory, a command has failed, etc. To find all available hooks, see doc hooks.`) return rt.TableValue(mod), nil } func handleHook(t *rt.Thread, c *rt.GoCont, name string, catcher *rt.Closure, args ...interface{}) { funcVal := rt.FunctionValue(catcher) var luaArgs []rt.Value for _, arg := range args { var luarg rt.Value switch arg.(type) { case rt.Value: luarg = arg.(rt.Value) default: luarg = rt.AsValue(arg) } luaArgs = append(luaArgs, luarg) } _, err := rt.Call1(t, funcVal, luaArgs...) if err != nil { e := rt.NewError(rt.StringValue(err.Error())) e = e.AddContext(c.Next(), 1) // panicking here won't actually cause hilbish to panic and instead will // print the error and remove the hook (look at emission recover from above) panic(e) } } // throw(name, ...args) // Throws a hook with `name` with the provided `args` // --- @param name string // --- @vararg any func (b *Bait) bthrow(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { if err := c.Check1Arg(); err != nil { return nil, err } name, err := c.StringArg(0) if err != nil { return nil, err } ifaceSlice := make([]interface{}, len(c.Etc())) for i, v := range c.Etc() { ifaceSlice[i] = v } b.Emit(name, ifaceSlice...) return c.Next(), nil } // catch(name, cb) // Catches a hook with `name`. Runs the `cb` when it is thrown // --- @param name string // --- @param cb function func (b *Bait) bcatch(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { name, catcher, err := util.HandleStrCallback(t, c) if err != nil { return nil, err } b.OnLua(name, catcher) return c.Next(), nil } // catchOnce(name, cb) // Same as catch, but only runs the `cb` once and then removes the hook // --- @param name string // --- @param cb function func (b *Bait) bcatchOnce(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) { name, catcher, err := util.HandleStrCallback(t, c) if err != nil { return nil, err } // todo: add once b.On(name, func(args ...interface{}) { handleHook(t, c, name, catcher, args...) }) return c.Next(), nil }