A Betakey loop is failing

ID:139161
 
May 28 2011, 5:57 am
Code:
var/newkey = ""//this is for the new betakey setup
verb
    AddKey()//randomizes a key for you to use
        var/num = input("How many keys do you want? Max of 100")as num//how many keys do you want?
        if(num>>100)
            num=100
        else if(num <= 0)
            num = 1
        while(num)
            RandomBetaKey()
            betakeylist+=newkey
proc
    RandomBetaKey()//the process for making a new betakey

        var/html = ""
        var/n = rand(1,26)//randomize n
        var/char = ""
        loop//set a link for a looping later
        spawn()
            switch(n)//randomize n again
                if(1)//if n == 1 the char var will be A
                    char = "A"
                else if (2)//repeat for each letter of alphabet, increasing n by 1
                    char = "B"
                else if (3)
                    char = "C"
                else if (4)
                    char = "D"
                else if (5)
                    char = "E"
                else if (6)
                    char = "F"
                else if (7)
                    char = "G"
                else if (8)
                    char = "H"
                else if (9)
                    char = "I"
                else if (10)
                    char = "J"
                else if (11)
                    char = "K"
                else if (12)
                    char = "L"
                else if (13)
                    char = "M"
                else if (14)
                    char = "N"
                else if (15)
                    char = "O"
                else if (16)
                    char = "P"
                else if (17)
                    char = "Q"
                else if (18)
                    char = "R"
                else if (19)
                    char = "S"
                else if (20)
                    char = "T"
                else if (21)
                    char = "U"
                else if (22)
                    char = "V"
                else if (23)
                    char = "W"
                else if (24)
                    char = "X"
                else if (25)
                    char = "Y"
                else if (26)
                    char = "Z"
        if(length(html)==4)//after 4 chars
            html+="-"//add a -
            goto loop//loop this
        else if(length(html)==9)//after the second set of 4
            html+="-"//add -
            goto loop//loop
        else if(length(html)==14)//after the third set
            html+="-"
            goto loop
        else if(length(html)==19)//after the fourth set
            html+="-"
        else if(length(html)>=23)//when we finish
            goto end
        else//if the length is not specified and we haven't ended yet
            html+=char//add the char to html
            goto loop//loop
        end//link for end
        newkey = html//make the variable newkey as html (so we can have the verb make the new key and such)


Problem description:
When I run the AddKey Verb, it literally crashes the world. The window turns non responding, I waited 15 minutes but it never finished, and I only tried making one (1) key.
May 28 2011, 6:24 am (Edited on May 28 2011, 6:41 am)
The reason for that happening is due to the while(num) in AddKey() is causing an infinite loop (because you did not add 'break' nor decrease num's value to 0 which can break the loop).

In your RandomBetaKey():
  1. To make the procedure more efficient, use while() instead of label... go to label... you can break out of the loop by using break. It's probably best if you did while(length(html) < 23) so that the loop breaks when html is >= 23 in length.
  2. You are using switch() incorrectly. For all options, you must use if(), once 'else' appears (including in 'else if') - it breaks out of the switch(). This means you are saying: 
    switch(n)
       if(1)
          char = "A"
       else
           if(2) //  Always true since it is no longer considered to be part of the switch()
               char = "B"
           ... etc... which doesn't matter since B will always be true
    The way you have it now will result in a 1/26 chance for A and 25/26 chance for B with no chance for all the other letters.

    The correct method would be: 
    switch(n)
       if(1)
          char = "A"
       if(2)
          char = "B"
       if(3)
          char = "C"
       ...etc...
       else
           None of the if() above happened and this was called
       if(X)
           This will never be checked as it happens after the 'else', which is like a break for switch()
  3. For more efficiency, you can use ascii2text(100+n+((n-(n%8))/4)) or ascii2text(100+n+(n<8)0?:(n<16)?2:(n<24)?4:6) to produce A-Z instead of one giant switch(). This is due to the ASCII result for 101 is A, 102 is B ... and 132 is Z. Note that 1X8 & 1X9 are other characters
    http://www.asciitable.com/
May 28 2011, 7:08 am
In response to GhostAnime
Thank you!

I fixed the while(num) loop and added 'num--' to the end of it. It does now output a key (after I fixed the RandomBetaKey() process). I would never have thought of using the ascii2text() process, I would have kept switching for the characters. Again, thank you! I now successfully have it output a key using your help. If only BYOND had a rep system.
May 28 2011, 7:29 am
In response to Fluidfire
You're welcome. One thing I forgot to point out is the >> in your first if() statement. It will not give you the effect of > as the >> would be a bit shift operator.

You can replace 
      if(num>100)
            num=100
        else if(num <= 0)
            num = 1
with 
num = max(1,min(100, num))
to limit the range to 1 - 100 (max() picks the highest number so that the lowest possible # is 0... ex: max(3, 0) = 3, max(-4, 0) = 0. Same idea with min() and 100)
May 28 2011, 7:54 am
In response to GhostAnime
Thats a rather handy tip, thank you, must be more effective than the 'if' method as well. I have much left to learn about DM. I must go find another neat idea, mess around with it, break it, and ask for help again later ._.