Creating a variable from a string?

[Yen]

Is it possible to create a new variable from a string?

For example, if I have:

NPC Code:

---

function onPlayerEnters() {

  this.txt = "owner=Yen";

}

---

Can I make it read this.txt and carry out the string as a function?
In this case, it would set the string 'owner' to 'Yen'

[PrinceDark]

I ws wondering about something like this as well, but I haven't figured out how to do this in GS2.

I wanted to get something like this below, but in gs2.

NPC Code:

---

// GS1

setstring myvars,apple,banana,fruit;



for ( i = 0; i < sarraylen(myvars); i ++ ) {

  setstring this.varname,#I(myvars,i);

  setstring this.#s(this.myvarname),#v(random(1,10));

}

---

Probably a bad example, but I haven't found a way to do this with GS2 and I'm effed since I have no where to script & test online.

edit: Someone told me about a makevar function can help with this, but I can't find any documentation on it.
Any help please?

[Admins]

http://wiki.graal.us/GS1_To_GS2#Easi...ring_variables

this.(@myvars[i]) = random(1,10);

[ApothiX]

makevar("varname") = "blah"; works aswell, IIRC.

[Yen]

You all misunderstood.
I want to make it perform the actions that are in a string.

For example.

this.txt = "putexplosion(2,30,30)";
DoFunctions(this.txt);

This would put an explosion with a radius of 2 at 30,30.

[napo_p2p]

Originally Posted by Yen

You all misunderstood.
I want to make it perform the actions that are in a string.

For example.

this.txt = "putexplosion(2,30,30)";
DoFunctions(this.txt);

This would put an explosion with a radius of 2 at 30,30.

I don't think there is a way to call default functions like that. What you could do is have doFunctions trigger 'custom' ones that have the functionality of default ones.

[Lance]

Originally Posted by Yen

You all misunderstood.
I want to make it perform the actions that are in a string.

For example.

this.txt = "putexplosion(2,30,30)";
DoFunctions(this.txt);

This would put an explosion with a radius of 2 at 30,30.

If you can call that function, can you not simply call what you were passing to it as an argument?

[Skyld]

Could have probably named the thread better.

Originally Posted by Yen

You all misunderstood.
I want to make it perform the actions that are in a string.

For example.

this.txt = "putexplosion(2,30,30)";
DoFunctions(this.txt);

This would put an explosion with a radius of 2 at 30,30.

I know the behaviour you're trying to achieve, but it can't be done unless you're working with a putnpc2.

The function you're looking for is called eval(), which would run whatever you passed to it:

NPC Code:

---

eval("putexplosion(2, 30, 30);");

---

... but for safety reasons, that function is disabled to prevent people being able to write incredibly malicious scripts and using them to cause hellfire and damnation on servers.

Side-note: This is why you can't type things into the Graal console on some Graal versions which support it!

If you're working with a putnpc2, however, then I suppose you could do:

NPC Code:

---

putnpc2(x, y, "putexplosion(2, 30, 30); destroy();");

---

[Admins]

I guess you can dynamically call functions, but function name and parameters must be stored independently, not in one single string. Example:

PHP Code:

functionname = "say2";
functionparam1 = "Hello!";
(@functionname)(functionparam1); 


or

PHP Code:

functionandparams = "putexplosion,2,30,30";
(@functionandparams[0])(functionandparams[1], functionandparams[2], functionandparams[3]); 


Such stuff should only be done by experienced scripters though, since it can be quite insecure.

[Yen]

Thanks! That was what I was looking for.

Another question..
Where different functions have a different number of params, is there any way to access an array and use each entry as a seperate parameter?
For example..

PHP Code:

functionname = "putexplosion"; 
functionparamz = {0,player.x,player.y}; 
(@functionname)(functionparamz); 


[Admins]

Not right now although you can just pass as many parameters as you want, it is only complaining if there are not enough parameters

[Yen]

Thanks a lot!
If Stefan weren't old, I'd marry him. Definately.

[jake13jake]

overloaded functions would be a handy thing.

[napo_p2p]

Spiffy.

[jake13jake]

Originally Posted by Stefan

Such stuff should only be done by experienced scripters though, since it can be quite insecure

hmmm... What makes it insecure?

[Skyld]

Originally Posted by jake13jake

hmmm... What makes it insecure?

If used in, say, a badly thought out triggeraction, then people could abuse it by using hacks to triggeraction and run functions.

[jake13jake]

Originally Posted by Skyld

If used in, say, a badly thought out triggeraction, then people could abuse it by using hacks to triggeraction and run functions.

a good thing I wouldn't use it that way

[Skyld]

Originally Posted by jake13jake

a good thing I wouldn't use it that way

I think we agree that it's a good thing if nobody uses it that way.

[Admins]

Originally Posted by jake13jake

overloaded functions would be a handy thing.

You can overload already, or what do you mean exactly ?

[jake13jake]

Originally Posted by Stefan

You can overload already, or what do you mean exactly ?

Something in the sense where you can have a function of the same name with different sets of parameters, and the function that is called is the one with the correct amount of parameters. It probably wouldn't be that useful in gscript since you can't declare variable types though (but I actually enjoy this flexibility).

like:
function test(String s, int n) vs. function test(int n, String s), but still, if you didn't want to necessarily use all of your parameters it might be useful

In essence (although you probably wouldn't use it this way):

NPC Code:

---

function test(param1) {

  chat = param1;

}

function test(param1,param2) {

  chat = param2;

  headimg = param1;

}



function test(param1,param2,param3) {

  chat = param3 @ param2;

  headimg = param1;

}

---

It would also be neat if you had an option of doing:

serverside function onCreated() {}
clientside function onCreated() {}

rather than
function onCreated() {}
//#CLIENTSIDE
function onCreated() {}

[Admins]

You can still do stuff like this though:

PHP Code:

function test() {
  switch (params.size()) {
...
  }
} 


[jake13jake]

Originally Posted by Stefan

You can still do stuff like this though:

PHP Code:

function test() {
  switch (params.size()) {
...
  }
} 


So if you send a function unnamed parameters they're loaded into the params array?
Is it possible to call event handlers when the event hasn't occured? I wouldn't really recommend this either.
Also, would setTimer(0) immediately call onTimeOut?

[Yen]

Yes.

[jake13jake]

Originally Posted by Yen

Yes.

Knowing this is very useful, thank you.

[ApothiX]

Originally Posted by jake13jake

It would also be neat if you had an option of doing:

serverside function onCreated() {}
clientside function onCreated() {}

rather than
function onCreated() {}
//#CLIENTSIDE
function onCreated() {}

I disagree with this. This would lead to extremely badly structured code, and I would assume it would grant people more problems then they already have.

Having the //#CLIENTSIDE directive is a nice way to split your code between serverside and clientside, there is really no need to have it all jumbled together.

[Skyld]

Originally Posted by jake13jake

It would also be neat if you had an option of doing:

serverside function onCreated() {}
clientside function onCreated() {}

rather than
function onCreated() {}
//#CLIENTSIDE
function onCreated() {}

I don't like the idea of your client sending functions to the server, either. Hacking could result in changing the contents of the function being sent.

Seperate them on the serverside, you say? Well, what's wrong with the current //#CLIENTSIDE method?

[Admins]

Originally Posted by jake13jake

So if you send a function unnamed parameters they're loaded into the params array?

They are always loaded into params[]

Originally Posted by jake13jake

Is it possible to call event handlers when the event hasn't occured?

Yes, like a function call.

Originally Posted by jake13jake

Also, would setTimer(0) immediately call onTimeOut?

No, it would unset the timeout.

[Ajira]

Originally Posted by jake13jake

Also, would setTimer(0) immediately call onTimeOut?

Just do 'onTimeOut();' in your script.

There goes my 1 post per day.

[jake13jake]

Hmm, is there anyway to load an operator from a string?
like

temp.calc (+)= tokens[i];

[Admins]

No I don't think

[ApothiX]

PHP Code:

function doOperator(var1, operator, var2) {
  switch(operator) {
  case "+":
    return var1 + var2;
    break;

  // etc..
  }
} 


[Fry]

And then it gets more complex and we get as far as rewriting GS2 in GS2?

An eval with some restrictions (like Ruby's $SAFE variable) would be a possible replacement maybe. For example, let's call the imaginary function seval and expect a security level and the code that should be evaled. Security level 1 could mean "don't allow triggeractions", 2 could mean "don't allow player warping", or even "variables are read only" and so on.
I am not sure whether that's possible for GS2, depends on the way it has been designed, but certainly it'd be better than putnpc2.

[jake13jake]

haha, apothix, that way is the obvious way, but if there were a way to take it from a string it would make that code one line, which is why i asked.

[Skyld]

Originally Posted by jake13jake

haha, apothix, that way is the obvious way, but if there were a way to take it from a string it would make that code one line, which is why i asked.

Put custom functions in a class or so.

[jake13jake]

Originally Posted by Skyld

Put custom functions in a class or so.

Just wondering, where is this coming from?

[ApothiX]

Originally Posted by jake13jake

haha, apothix, that way is the obvious way, but if there were a way to take it from a string it would make that code one line, which is why i asked.

use tokenize, and parse the line

[Skyld]

Originally Posted by jake13jake

Just wondering, where is this coming from?

Well, you said about wanting to use few lines in your script.

Write a function and save it into a class, and join() it, if you're that worried about clutter in your script.

[jake13jake]

Originally Posted by ApothiX

use tokenize, and parse the line

Now I'm confused.
Anyways, I do use tokenize in this script. However, if I were to make it have real functionality, it might be better to parse it myself.
Using tokenize to parse it, you'd want to have custom delimeters +,-,*,/,%,^,(,)
But either way, you're going to have to figure out what you skipped anyway.
So you could parse it yourself, and then store as args and operators. You'd probably store the numbers and operators in scattered arrays, and then try to find some way of applying the order of operations.