Constant Functions

I see ppl use these. Whats the diff between these and variables? What are its benefits?

A constant is something that will never change, because of that it will process much faster.

If you know something will never change, you can keep it in the back of you mind and remember it real quick. But if you don't know if it's changed or not, you have to check real quick in the book. That takes time to look through the book, so it takes longer.

This is just an analogy.

Analogy = ?

From your explanation of a constant, it seems like a variable that you would need to remember all the time...huh? I don't get it.

In warcraft, 'constant' is a syntactical constraint that ensures a function does not call any non-constant functions and does not use the set statement. It has no effect on the generated code. In practice we use the constant keyword to denote data such as spell configuration. When used in this manner, Vex's optimizer may be able to inline the function for improved performance.

pipedream : I get more more confused with your explaination -.-"

well constant is just a number that remain the same, a very simple example : one day have 24 hour, so the 24 is a constant, and it never change. Variable is something changing... well in your science experiment you often in contant with some manipulated variable and responding variable... arrr this is getting longer...

anyway for an example, lets say a line equation, y=mx+c, so y is the responding variable, m and c are more or less the constant (they dont change no matter what x you put in) and x is the manipulated variable. Understand this and you will one step closer to understanding functions.

It looks like this topic strayed off-course, so I'm going to answer the posters question to the best of my abilities.

Joker, a constant function is used in place of a variable, because:
1) It's easy to change.
2) All your constants for one "idea" (spell, system, etc.) are in a single area, instead of spread-out along the variable manager.
3) It requires no global variable to create, which makes the "idea" easier to copy from map to map. Instead of having a list of "variables required and their default properties" the user just copies the entire "idea" and doesn't have to worry about all of that.

Hope this answers your question.

Constants functions == functions with restraints.

Only really useful with Vex's optimiser.

why and whats does vex's optim do?

Read Pipe's post. Rule of thumb: Pipe is Always Right.

Vex's optimizer opens up your map or a script and decreases the size of it by using many different methods, and most of those methods deal with decreasing the size of the map's script. Since constant functions are limited in what they can do, the optimizer can inline them or something to improve performance. Basically, a constant function is a function that cannot call non-constant functions or set variables (from my understanding).

Hey, I reclaim the authorship of that rule.

Eventually, the optimizer will get 'smarter' and not require the constant keyword to inline, either way I think it is still great as a way to document code. A constant function or a constant 'variable' make sense to differentiate configuration from actual code. Although it does increase the chances of WE's compiler crashing when saving but it is not like a human being would actually use that compiler...

so am i able to set a constant function for anything? like triggers, units, reals, etc

that question is confusing

I guess some examples will help:
OK

OK

ERROR

ERROR

ERROR

Quoted from Wikipedia.