Make rednet functions throw an error if rednet isn't open.

I'm not sure if it's just me because I'm stupid, but when I make rednet-based programs, I almost always forget to place a modem on the computers and to open them. I'm sitting here for half an hour trying to figure out why nothing is happening and I don't fix it right away because I'm not given an error.

Errors are annoying, but at the same time, they're probably one of the best things in programming. They tell you exactly where and how you've screwed up. It would be monumentally helpful if the computers simply stopped the program and told you to open rednet, instead of doing nothing. It's like someone screaming at you constantly, without telling you why.

Nah, just try to remember the rednet…..

Cranium, on 04 October 2012 - 12:20 AM said:

Nah, just try to remember the rednet…..

Haha, you think I didn't already try that?

Sticky notes, brah….best way to remember ANYTHING.

Is there a sticky note mod for minecraft? :U

The difficulty with this is rednet also works on bundled cables - and no easy way to detect them.

Cloudy, on 04 October 2012 - 12:54 AM said:

The difficulty with this is rednet also works on bundled cables - and no easy way to detect them.

It would be awesome if they could though… But no, there is no sticky note mod…as far as I know, anyway… They are in what we call "The real world" in a fanciful place called "Outside". It's all the rage these days. :(/>/>

Cloudy, on 04 October 2012 - 12:54 AM said:

The difficulty with this is rednet also works on bundled cables - and no easy way to detect them.

Wouldn't rednet.send() or rednet.broadcast() return false if called without rednet open?

So instead of returning false, would it be possible to instead simply give an error?

In fact I could do some edits and make it so that it errors myself, just by storing the function as a local function and redefining the global one to error if the result of the stored local function is false.

Cloudy, on 04 October 2012 - 12:54 AM said:

The difficulty with this is rednet also works on bundled cables - and no easy way to detect them.

You still have to open the bundled cables. "Throw an error if no sides are open" is much easier than "throw an error if no modems or cables are connected".
Throwing the error could break existing programs though.

The programs shouldn't try to send rednet signals without an open modem anyway. Programs would do the same in real life, right? If there's no internet connection available?

I know you're not going for realism here, but that's just something I'd imagine a program would do - throw an error if there's no medium through which to send rednet signals.

Kingdaro, on 04 October 2012 - 02:51 AM said:

The programs shouldn't try to send rednet signals without an open modem anyway. Programs would do the same in real life, right? If there's no internet connection available?

I know you're not going for realism here, but that's just something I'd imagine a program would do - throw an error if there's no medium through which to send rednet signals.

Actually, depending on the scenario, lots of communication systems send data regardless of connected media. They do throw an error though, when no data is coming back. (This is implemented in multiple layers of the ISO OSI model). You could go for that approach…

It'd be crappy practice for it to throw an error. Making it crash because the network is unavailable? That's silly. Network is never a reliable thing. If Chrome crashed every time i wasn't connected to wifi i'd be pretty annoyed. The fact that send and broadcast return false when there's no rednet is perfect.

Agree. I also did that once and was struggling for 30 minutes to figure out that I just forgot to open the modem.

ElvishJerricco, on 04 October 2012 - 04:13 AM said:

It'd be crappy practice for it to throw an error. Making it crash because the network is unavailable? That's silly. Network is never a reliable thing. If Chrome crashed every time i wasn't connected to wifi i'd be pretty annoyed. The fact that send and broadcast return false when there's no rednet is perfect.

This is not really good comparison.

1. Chrome would throw an error if there is no network
2. Rednet IS reliable, there is always a network. Why would rednet opening/closing be unreliable?

Rednet.send returns a sucess boolean.

Kingdaro, on 04 October 2012 - 01:20 AM said:

Wouldn't rednet.send() or rednet.broadcast() return false if called without rednet open?
So instead of returning false, would it be possible to instead simply give an error?

So you got result_success=false but want your program to be stopped?
Use some assertion wrapping for yourself. No need to demand it for all.

Sebra for the win. So I pile on top with some noobish ranting.

If you aren't familiar with it, there is an error command in the APIs somewhere. Using that, I have prepared a noob code fragment for you.

if not rednet.send(id, msg) then
   if rednet.isOpen() then
      print("ID or message Invaild")
   else
      error("No network detected")
   end
else
   print("Message Sent, awaiting response.")
end

And I just pressed control thinking I was typing in minecraft. >.<

OmegaVest, on 04 October 2012 - 10:41 PM said:

And I just pressed control thinking I was typing in minecraft. >.<

That's alright. I have been pressing t in IRC lately to bring up the chat console… >.<

ardera, on 04 October 2012 - 03:21 PM said:

Rednet.send returns a sucess boolean.

I've already addressed this, and I will explain in further detail below.

Sebra, on 04 October 2012 - 04:32 PM said:

So you got result_success=false but want your program to be stopped?
Use some assertion wrapping for yourself. No need to demand it for all.

This doesn't even relate to the reason why I ask for this. When I make a program, all I type is "rednet.send 'blahblahblah'" and it takes me a while to figure out why nothing's happening because I'm not told that I'm doing something wrong - like basically every other mistake in programming, syntax errors and nil calls for example. It's the same as typing something without parentheses and the program still (somehow) continues on it's merry way.

By the time I've already written checks to see if the modem is there, I can already see if it's there because I have eyes, so there would be no point in doing so.

Also, I'm not "demanding", I'm making a request, but with stronger wording. I've proved in a tumblr post that periods make sentences more serious than if they were without periods, sorry for the misconception.

So you want an API to throw a fatal error, breaking many existing programs, instead of failing gracefully, because you don't want to change your habits?

Fatal_Exception, on 04 October 2012 - 11:58 PM said:

So you want an API to throw a fatal error, breaking many existing programs, instead of failing gracefully, because you don't want to change your habits?

If there really are that many programs that send rednet signals without opening their modem first, I suppose it makes sense.

Otherwise there shouldn't be a problem.

Or perhaps, if you, for some reason, wanted to send rednet signals without the modem open, you could just pass an argument like 1 to the function to prevent it from erroring?

Or you could check for error conditions in your own code like a responsible programmer.

Or you could put this in your startup:

local send = rednet.send
rednet.send = function(...) return assert(send(...), "No modem open.") end

Since it loads automatically you can't forget it.

And then I have to reference this because it seems that you've skipped over it:

Kingdaro, on 04 October 2012 - 11:50 PM said:

This doesn't even relate to the reason why I ask for this. When I make a program, all I type is "rednet.send 'blahblahblah'" and it takes me a while to figure out why nothing's happening because I'm not told that I'm doing something wrong - like basically every other mistake in programming, syntax errors and nil calls for example. It's the same as typing something without parentheses and the program still (somehow) continues on it's merry way.

By the time I've already written checks to see if the modem is there, I can already see if it's there because I have eyes, so there would be no point in doing so.

Also, I'm not "demanding", I'm making a request, but with stronger wording. I've proved in a tumblr post that periods make sentences more serious than if they were without periods, sorry for the misconception.

faubiguy, on 05 October 2012 - 12:15 AM said:

Or you could put this in your startup:

local send = rednet.send
rednet.send = function(...) return assert(send(...), "No modem open.") end

Since it loads automatically you can't forget it.

I was going to do this anyway though.

To be honest, it returns false. Would it be so hard for you to just check if it succeeded? Heck even assert would throw an error for you.

assert(rednet.send(), "Could not send. Please check port open")

Also even if you type rednet.send() in the lua prompt it will show a false return value.

Cloudy, on 05 October 2012 - 12:42 AM said:

To be honest, it returns false. Would it be so hard for you to just check if it succeeded? Heck even assert would throw an error for you.

assert(rednet.send(), "Could not send. Please check port open")

Also even if you type rednet.send() in the lua prompt it will show a false return value.

As I've already said before, by the time I've already made the check I will have remembered to throw the modem on and open rednet.

I don't really feel like repeating myself though, so just lock it or something.

If you make it a habit to always check return values when things can fail, you won't be surprised when they do. See: responsibility.

your repeating the same things over and over, just make your own function to open it and error if its not on, and even open the first available modem instead of specifying one

i dont get it? how do you forget to use rednet.open(),
and when you do that you sould automatically check if its on the right side

Why not just ask for the modems to come connected to the computers and auto enable?? lol J/K J/K!!!!

This is really just a personal issue, you need to figure out how to remember to turn them on. The mod can't do everything for you, there just wouldn't be any fun in that.

I forget it from time to time, but thats my fault. I've made my own little function that I put in all programs to check for it and yell at me if I forget. Its part of the standard set of functions that I put in all of my scripts.

Since I don't see the point in this - we already do something when failed - I'm closing this topic. I do understand your point, but we can't error for every single thing.