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Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

You may recognize this request from previous threads but I still need a solution. I hope someone can tell me a great way to do this in CMUD. What I want is what I ask for so please don't suggest alternatives like queues and such. They are not what I am looking for.

I need an alias that sends a command to the mud and await a certain response line from the mud before proceeding. I must be able to stop the command if for some reason the line of text I expect to see is not received.

I expect to use it like this perhaps:

Wizard Joined: 03 Mar 2001 Posts: 1127 Location: London

#WAITFOR seems to do exactly what you ask

GURU Joined: 23 Dec 2000 Posts: 4834 Location: USA

Use a multistate trigger:

#oninput {pick up rock} {}
#condition {You pick up} {throw rock}
#condition {You throw your rock} {pick up rock}

That's the basic outline, at least. The multi-state trigger stuff will make sure nothing executes out of order.

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sat Feb 09, 2008 11:00 pm

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sat Feb 09, 2008 11:24 pm

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sat Feb 09, 2008 11:47 pm

My comments have been constructive comments, I'm not sure how you can have construed them otherwise, perhaps there is a language barrier occurring. I think you are misunderstanding what I am saying. Forget that the way to cancel a #WAITFOR was called timeout and just rename it in your head to cancel since that is exactly what it does it cancels the #WAITFOR, you no longer want to wait and it stops you waiting, the bonus is you didn't have to press a button to achieve your not waiting any more.

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Well, perhaps there IS a language barrier here. In my world being constructive means that you help solving the problem. Until now you have only thrown short comments on my answer to Guinn's suggestion.

Well, bring on the solution if you have it, Taz. Show me how I can cancel a #WAITFOR. Do remember that I want to cancel it when I want on runtime. Setting a hardcoded timeout is no good.

Adept Joined: 04 Feb 2005 Posts: 246

If the "cancel" situation is simple, as in "not getting the response you expect within some number of lines" I use "within lines" #COND trigger. That cancels the entire trigger when you don't get it fast enough.

If the situation is more complicated, like canceling on command, I'm more prone to use a class I enable and disable. I know I could do that with #STATE commands too, but I just usually don't.

There are problems using #WAIT* to do this. A thread that is waiting uses resources. I imagine that if you #WAIT* enough where the response never comes, you'll start to chew up memory. Worse, if you ever trigger the condition, you'll then let all N threads go at once. For example, if you say "pick up rock" where there wasn't one, you might still be waiting. Say it again, and now you have two waiting. Go to a room minutes later, do "pick up rock" and when the correct response comes, you'll have 3 commands trigger on the response.

With your feedbackcommand, you will run into the problem I outlined in another thread. You'll be waiting on a response that isn't coming. If you try another feedbackcommand for a different (or same) command, you'll have two concurrent feedbackcommands pending, and that isn't thread-safe.

Posted: Sun Feb 10, 2008 12:07 am

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sun Feb 10, 2008 12:23 am

As long as there isn't more than one feedbackCommand waiting at a time it will work fine. If you wanted to extend it to allow that you would need to start using trigger ids and pass the id in as $id to your alias.

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sun Feb 10, 2008 12:44 am

#ALIAS feedbackCommand($id, $command, $feedback) {#THREAD $id {#WAITFOR {$feedback} {$command}}}
#ALIAS cancelFeedback($id) {#STOP $id}

feedbackCommand "pr" "throw rock at monster" "You pick up"
cancelFeedback pr

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sun Feb 10, 2008 1:04 am

The client will never send the command "throw rock at monster" to the mud if it never receives the feedback "You pick up" from the mud, that is your blocking.

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Posted: Sun Feb 10, 2008 1:31 am

I was under the impression that it isn't possible to block the main thread, that is why threads were put in to start off with so that the client continues to respond to your input no matter what you've told it to do.

I think you're saying that you block the main thread when you do #WAITSIGNAL but I'm fairly certain this creates a new thread.

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

Nope, #WAITSIGNAL is main thread... Smile

Posted: Sun Feb 10, 2008 1:44 am

I just checked, a new thread is definitely created!

Magician Joined: 18 Dec 2006 Posts: 317 Location: Denmark

How can you tell?

Anyway, the documentation says that it's suspending the current thread and it works that way too. Try it out - the working alias is somewhere in this thread. You just need to change "myprompt>" to hwo your own prompt looks.

Posted: Sun Feb 10, 2008 1:55 am

#thread lists the current threads.

I have your alias created by copying and pasting from earlier in this set of posts. It is what I used in order to check about the threads. If you type #thread in a new session you will see only 1 thread is listed, after using your alias you will see there are 2 threads listed.