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[Scooternew]

Scooternew

[Request / Listing] execute_string apparently ca...

I was just playing around with execute_string, and lo and behold, I found something out;

Code: [Select]

var temp;
temp = 20;
execute_string("if(temp > 15) {keyboard_wait();};");

I was just trying to test something out with execute string, and for some reason, execute_string doesn't seem to recognize temp as a variable. Is there a reason that this happens, or am I just a blabbering idiot? If not, does anyone know a way around this problem?

[mit]

mit

Re: execute_string apparently can't read temp va...

Interesting, I hadn't noticed that. It can read globals, and temp vars should be global...

Well, you could get around it by doing

Code: [Select]

var temp;
temp = 20;
execute_string(
   "var temp; temp="+string(temp)+";"+
   "if(temp > 15) {keyboard_wait();};"
   );
if ya know what I'm saying. I suppose the definition of the temp var is that it lasts until the end of the current peice of code, and so only within the current peice of code, and the execute_string must be classed as a different peice of code.

Programmer / Spriter / Level designer / Game Director / Web Designer / Music Sequencer for
Random Highscore table:

Play the Kousou Arcade today!

• 

[Infinitus]

Infinitus

Re: execute_string apparently can't read temp va...

Chances are if the scripting language is any good, when you call execute_string its creating a new stack frame and execution context. Which would stop your from accessing locals as they would be on a different stack frame. Globals would probably be accessable as i believe gm keeps a globals outside the scripts stack.

[mit]

mit

Re: execute_string apparently can't read temp va...

Upon testing this, temp vars are not global or local, they're on their own little planet.

This doesn't work, as we know:

Code: [Select]

var temp;
temp="HELLO!"
execute_string("draw_text(x,y,temp);");
However, this does:

Code: [Select]

var temp;
temp="HELLO!"
with (all){draw_text(x,y,temp);}
And likewise this doesn't work at all:

Code: [Select]

var temp;
temp="HELLO!"
with (all){execute_string("draw_text(x,y,temp);");}
My solution above works;

Code: [Select]

var temp; temp='HELLO!';
execute_string("var temp; temp='"+string(temp)+"';"+"draw_text(x,y,temp);");
To investigate more, I ran this:

Code: [Select]

var temp;
temp="HELLO!"
if variable_global_exists(temp) draw_text(x,y,"'tis a global!");
if variable_local_exists(temp) draw_text(x,y,"'tis a local!");Which sadly states that GM doesn't class them as either. This may just be the functions, but meh.

execute_string does work with local and global vars though, both

Code: [Select]

temp="HELLO!";
execute_string("draw_text(x,y,temp);");and

Code: [Select]

global.temp="HELLO!";
execute_string("draw_text(x,y,global.temp);");work.

Programmer / Spriter / Level designer / Game Director / Web Designer / Music Sequencer for
Random Highscore table:

Play the Kousou Arcade today!

• 

[Infinitus]

Infinitus

Re: execute_string apparently can't read temp va...

@Mit well actually they are local, as i tryed to explain in my previous post, locals can only be accessed by the stack frame is is defined in. As soon as you call execute_string it creates a whole new stack frame, and thus the previously declared variables can't be used.

Sorry if you dont understand what i mean, you need a basic grasp of how languages work to understand.

[mit]

mit

Re: execute_string apparently can't read temp va...

Nah, I do understand, it's just what I'm saying is, in GM usually with a local variable,

Code: [Select]

myvar=5;
with (another instance) { if (myvar<10) dosomething(); }
wouldn't work, as the variable would be local, and the control over the other object would be checking its own local variable myvar, which wouldn't be set. You have to refer to it as instancename.myvar, and so on. However, with the var command in GM, they span across the with thingy, so 

Code: [Select]

var myvar;
myvar=5;
with (another instance) { if (myvar<10) dosomething(); }
does work.

Programmer / Spriter / Level designer / Game Director / Web Designer / Music Sequencer for
Random Highscore table:

Play the Kousou Arcade today!

• 

[Infinitus]

Infinitus

Re: execute_string apparently can't read temp va...

Might be that Var forces local behaviour, and undeclared variables are initilised as a global (or different).

[Scooternew]

Scooternew

Re: execute_string apparently can't read temp va...

Well, this is really weird. I've tried various combinations..but none seem to work.

If the execute_string can't read temp variables, maybe it is treated as a seperate script. Especially since you can declare temp variables within the method. I'm giong to do some more tests and see if I can find any information on the GMC about this.

[Windy]

Windy

Re: execute_string apparently can't read temp va...

does

Code: [Select]

var temp;
temp = 20;
execute_string("if("+string(temp)+" > 15) {keyboard_wait();};");
work?

[Scooternew]

Scooternew

Re: execute_string apparently can't read temp va...

The point isn't trying to fix this - the point is trying to understand why it happens. I guess execute_string has a differnet local scope than the script in which it is called.

But since this is true - it must be able to return. And according to this topic, my hypothesis is supported.

Lo and behold - it works! execute_string can return a value! Wow - talk about interesting.

http://gmot.chronic667.com/index.php?topic=1864.0

Look at J-Factor's post.

[AoDC]

AoDC

Re: execute_string apparently can't read temp va...

(Scooter: 20 trojans? Don't use IE! )

The issue is... I dont know. Maybe Mark didnt program execute_string to read temporary variables, but instead it checks for local and global. Other than that, No idea.

the a o d c

[Scooternew]

Scooternew

Re: execute_string apparently can't read temp va...

Yeah, I switched over to Firefox. IE is a !@#$%.

I actually solved this problem - look at the other link I posted.