Re: Best way to pause (sleep?) inside of lua script

[John Klimek <jklimek@...>]

Thanks for the examples!

So it seems like I can't do what I wanted above because suppose my
script was run twice and "myNewNpc" was created twice?  (once from
each script)

Whats the best way to handle this?  Even the example above wouldn't
work (local myNewNpc = NPCManager.GetNPC("Bob")) because suppose that
two NPC's were named Bob?



On 12/12/05, Pavel Antokolsky aka Zigmar <zigmar@gmail.com> wrote:
> On 12/12/05, John Klimek <jklimek@gmail.com> wrote:
> > Ok, I understand that I have to store this function in the Lua
> > registry, but how would I do this from my C/Delphi function?  Can you
> > give me a code example?
> See the attachment. I've created a simple app (with C++) that allows
> to register some hypothetic event handler and later calls to
> registered function.
>
> > Also, lets say I have the following code:
> >
> > -- Funcion to be executed later
> > function SayHello()
> >   myNewNpc:SayRoom("Hello everybody!");
> > end
> >
> > -- Create a new NPC and store it in "myNewNpc"
> > myNewNpc := NPCManager.New("Bob");
> >
> > -- Create a timer to run the SayHello function in 10 seconds
> > local eventId = mud:onTimer(10, SayHello);
> >
> > -- end of lua script
> >
> >
> > What would the code look like (in C/Delphi) for the onTimer function?
> > Also, if I store my function SayHello in the Lua registry and execute
> > it later, won't it lose the value of myNewNpc and then throw an error?
> >  Would I have to modify my function to something like this:
> No, you don't have to. A global variable are always visible and
> persistent - once you have declared it - it there until you remove it,
> even if the script body finished running. Actually lua-based ini files
> parsers - work line this - some variable are declared in script and
> host app exectues the script body, and read the global variables
> afterwards.
> Note the 'a' gloval variable in attached example.
>
> > function SayHello()
> >   myNewNpc = NPCManager.GetNPC("Bob");
> >   myNewNpc:SayRoom("Hello everybody!");
> > end
> Here you actually modify (or create) _global_ variable "myNewNpc". If
> you wanted to create local variable, you should have written:
>
> function SayHello()
>   local myNewNpc = NPCManager.GetNPC("Bob");
>   myNewNpc:SayRoom("Hello everybody!");
> end
>
>
> > On 12/11/05, Pavel Antokolsky aka Zigmar <zigmar@gmail.com> wrote:
> > > On 12/10/05, John Klimek <jklimek@gmail.com> wrote:
> > >
> > >  > Zigmar, can you explain what you mean when you say "register a
> > >  > function itself, not its name"?
> > >  Functions are first-class objects in lua, and therefore function can
> > > get another function as parameter, functions can be stored in
> > > variables, etc. So what I mean, as the function that registers event,
> > > can receive not the name of the function (which therefor must be
> > > global) but a function object itself. It allows you to pass local
> > > function, function stored in some tables or even anonymous function
> > > (as I wrote in example)
> > >
> > >  > For example, in your lua code you have:
> > >  > mud.onTimer(10, function() npc:say("Hello") end )
> > >  >
> > >  > It looks like mud is a table filled with cfunctions.  Am I right?
> > >  Yep. It probably some library filled with function that gives you a
> > > connectivity to your host application (mud server). For example
> > > queries about different statuses, registering/removing events,
> > > spawning monsters, etc.
> > >
> > >  > Furthermore it looks like you are calling this cfuntion (wherever
> > >  > mud.onTimer is mapped) and passing it a lua function parameter.  Am I
> > >  > right on this as well?
> > >  Exactly. onTimer is a function that registers user event and calls
> > > it with specific interval.
> > >
> > >  >  If so, how would you declare the cfunction
> > >  > onTimer that would handle this input?
> > >  Just like any other cfunction - you just handle the parameters on
> > > stack in appropriate way. The tricky thing is that you can non pop and
> > > store function object in C-app as you can do with strings. The
> > > function has to be stored inside lua state itself. To do this, you can
> > > use "registry".
> > >
> > >  >  Delphi examples are preferred
> > >  > but C/C++ will work too =)
> > >  Here is an excelent explanation, along with code examples
> > >  http://www.lua.org/pil/27.3.html
> > >
> > >  BTW, I  thought that it might be a good idea, that event registration
> > > function will return some kind of event id (integral or whatever), so
> > > it can be used later to remove that event notification.
> > >
> > >  For example:
> > >
> > >  local eventId = mud.onTimer(10, someFunc);
> > >  ....
> > >  mud.removeEvent(eventId); -- or maybe "removeTimerEvent"?
> > >  --from now on someFunc will not be called anymore
> > >
> > >
> > >  Also there should be some functionality to allow to reset all event
> > > notifications.
> > >
> > >
> > >  > Thanks!!
> > >  You are welcome :)
> > >
> > >  > On 12/9/05, Pavel Antokolsky aka Zigmar <zigmar@gmail.com> wrote:
> > >  > > Just an idea - I think it will be much more convinient and flexible to
> > >  > > register a function itself, not its name. Then, you can write
> > >  > > something like:
> > >  > >
> > >  > > -- Every ten seconds
> > >  > > mud.onTimer(10, function() npc:say("Hello") end )
> > >  > >
> > >  > > This system can be also extended to handle different events. For example:
> > >  > > mud:onRoomEnter("main", function(who,where) npc:say("Hello, " ..
> > > who.name) end )
> > >  > > it can be, for example, extended to handle rooms with masks
> > >  > > mud:onRoomEnter("dungeon_*",
> > >  > >    function(who, where)
> > >  > >        if where:name != "dungen_saferoom" then
> > >  > >            local monster = mud:spawn("monster",where)
> > >  > >            monter:attack(who)
> > >  > >        end
> > >  > >   end
> > >  > > )
> > >  > >
> > >  > > And so on... I can't even think of all possibilites with such system :)
>
> --
> Best regards,
> Zigmar
>
>
>