llSubStringIndex, parsing and efficiency

Hey all,

I'm a bit of a LSL newb (but I have a lot of experience being a newb in lots of other languages!), and I had a quick question about scripting efficiency, more for later than for now, but anyway...

For a script I'm writing, I needed to parse the first and last name of the avatar who touches a button. This was pretty easy to figure out:



But I was curious if that was the best way to do it. For example, I thought I could get rid of the inString step and that would be better.

so now I have



which saves me a string. For efficiency's sake, is it better to use functions like that, and maybe literals ( " " vs. oneSpace )? I feel like it's better to use variables for more readable code, but I was curious how I should be planning to mold my scripting habits.

Anyway, thanks for any input. Also, is there a bbCode for formatting the code output active on the forum?

ill

I always use literals for simple things like a space, for example, in 'llParseString2List(message, [" "], []);'

I would also likely declare a string variable in the event to store the result of llDetectedName, because I believe it's a little faster that way, and should cost less memory.

Lastly, don't you need to use the index of that space - 1 or + 1 for the first and last name respectively? At least, if you want to get rid of the space itself in those strings.

You can use the

 or 
CODE
 tags, and I recommend doing so, but it won't show up normally. To get it to format properly (since bbCode has been disabled here), I suggest installing the GreaseMonkey addon for FireFox and downloading the bbCode formatting script made by Strife Onizuka, I believe it's here: http://userscripts.org/scripts/show/9651.

You save the space for a string, but you end up calling a function 3 times. Usually, that's not a great trade-off. In SL things get weird though, because the built-in functions sometimes run faster than a few lines of code in a script, so... who knows

You could try and benchmark it. Put that code in a loop and run it 100,000 times and measure how long it takes (add some calls before and after it to get timestamps, diff, print result). Then do it the other way and measure that. Repeat both several times and see if you get a consistent difference.

You are correct, thanks for the catch. I didn't notice the double space in the output.




Sorry, I have a bad head for prefiguring how brutal code will be on a system -- is 100,000 times a bit excessive? I realize it might be less than a second to compute, but on the other hand I just don't want to be the one who brought down my sim.

I'm already afraid the neighbors don't like me.


Thanks for your replies!

Heh, good point, maybe start with a smaller number of iterations Ideally you'd want it to run for several seconds so your numbers are more meaningful, but you're right, it probably doesn't need to run for hours

For situations like this, in which I want to omit the delimiting character, I'd use llDeleteSubString, rather than llGetSubstring and the additional math to offset the index:

avatarFirstName = llDeleteSubString( inString, nameSplitIndex, -1 );
avatarLastName = llDeleteSubString( inString, 0, nameSplitIndex );

Personally, I'd just use llParseString2List. It's likely to be comparable in cost, and saves the headache of dealing with the off-by-1 errors.

No doubt.