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Wanderer Joined: 07 Oct 2001 Posts: 71

I understand the general concept of the local variables and that they greatly increase the speed of scripts using them over normal variables, just have a couple speed questions:

Is is always better to use local variables, or only when a variable in a script is referenced multiple times? This example seems pretty intuitive which would be faster, but anyway which is faster...

alias: kk
value: kill @enemy

or

alias: kk
value: $target=@enemy;kill $target

It would seem obvious that the first example is faster, simply because it's only 1 command, vs 2... wanted to verify though.

But what about this example...

alias: kk
value: kill %1

or

alias: kk
value: kill $target
parameter: target

With the new parameter option of alias to assign things to local variables, is that still acting as two commands, which way is faster?

Granted those are two very basic examples, and the speed difference is probably close to immesurable, just trying to get a better grasp on the actual affects of local variables and the parameter option.

Posted: Fri Oct 13, 2006 8:00 pm

In general, local variables will only speed things up if it is referenced more than once.

In your first example, the first version is technically faster, although the difference will be extremely small. Once the kk alias is compiled, the overhead from creating a local variable is very small.

In the second example, the two versions are the same speed. Using $target is just giving the compiler a name for the %1 variable. The compiled code for the first one uses the PARAMREF bytecode command, and the second one uses the LOCAL bytecode command, but these two commands do exactly the same thing (the only difference is that the LOCAL command has an extra integer argument to allow local variables from parent stack frames to be accessed).

Because the speed difference is negligable, I'd recommend using the first version of the first example, and the second version of the second example. Using named arguments will make your scripts more readable and easily supported than using the %1 variables, although for the simple case like you gave it probably doesn't matter.

Wanderer Joined: 07 Oct 2001 Posts: 71

Is there a way to use Params using a single local variable to mimic the %-1 option of zmud aliases?

So if in zmud I have an alias that is

Posted: Tue Oct 17, 2006 12:15 am

The %params function will return all of the parameters. %params is the same as %params(-1) which is the same as %-1

Wizard Joined: 14 Aug 2004 Posts: 1269

I think Rugbystyle may have been referring to named parameters to aliases...

Wanderer Joined: 07 Oct 2001 Posts: 71

Yeah, sorry - I should've been more specific. I didn't mean the literal use of "params". I wanted a way to use one parameter local variable that would take all of the input given. Like

Posted: Wed Oct 18, 2006 1:53 am

Just list all of the possible arguments:

#ALIAS ac ($arg1,$arg2,$arg3) {action=$arg1}

First, remember that you MUST put the $ before each argument name in the argument list.

Anyway, CMUD doesn't force you to call the alias with all of the arguments. The named arguments that were not passed values should just be null. Give it a try and see if it works.

Posted: Wed Oct 18, 2006 1:54 am

To clarify, if you want to use a single named argument to represent multiple arguments passed to it, then you can't. You'll need to stick with the %-1 syntax to access multiple arguments.

Wanderer Joined: 07 Oct 2001 Posts: 71

Gotcha, that's what I was wanting to find out. Thanks