Any way to store interpolated strings in a ShuffledList?

Authoring TADS
1

Hi,

I’m not sure if this is a bug or feature.

When I run the attached program, I get:

I’d expect the last line to be “true”. Is there any way to achieve this?

The program:

#include <adv3.h>

versionInfo: GameID {}

gameMain: GameMainDef {

    myBool = nil;

    myList: ShuffledList {
        ['<<if myBool>>true<<else>>nil<<end>>'];
    }

    showIntro() {
        "myBool is: <<reflectionServices.valToSymbol(myBool)>>\n";
        "<<myList.getNextValue()>>\n";
        myBool = true;
        "myBool is: <<reflectionServices.valToSymbol(myBool)>>\n";
        "<<myList.getNextValue()>>\n";
    }

}
2

In trying to test your code, I ran into a couple of problems. First, you put a semicolon after myBool=nil – I had to remove that. But now I get a more interesting error:

Having sorted that out, I get the same results you do. Evidently, the evaluation in the string is being stored when the string is created, not each time it’s printed.

3

Thanks for your reply.

Do you think there is any way to store strings with code in them in a list in such a way so that the code execution is deferred until the time I use the string?

4

FWIW, using anonymous functions here doesn’t work either, probably because they are implemented as closures which capture and use the original value of variables:

#include <adv3.h>

versionInfo: GameID {}

gameMain: GameMainDef {

    myBool = nil;

    myList: ShuffledEventList {
        [function() {if (myBool) "true\n"; else "nil\n";}];
    }

    showIntro() {
        "myBool is: <<reflectionServices.valToSymbol(myBool)>>\n";
        myList.doScript();
        myBool = true;
        "myBool is: <<reflectionServices.valToSymbol(myBool)>>\n";
        myList.doScript();
    }

}
5

In the last example, moving myBool out from the local scope seems to do the trick:

#include <adv3.h>

versionInfo: GameID {}

myGlobals: object {
    myBool = nil;
}

gameMain: GameMainDef {

    myList: ShuffledEventList {
        [function() {if (myGlobals.myBool) "true\n"; else "nil\n";}];
    }

    showIntro() {
        "myBool is: <<reflectionServices.valToSymbol(myGlobals.myBool)>>\n";
        myList.doScript();
        myGlobals.myBool = true;
        "myBool is: <<reflectionServices.valToSymbol(myGlobals.myBool)>>\n";
        myList.doScript();
    }

}

Now I get what I want:

myBool is: nil
nil
myBool is: true
true

Again, not sure if it’s a bug or feature.

6

I tried moving both myBool and the ShuffledList out of GameMainDef, but I put them both in the same object. It didn’t occur to me to try putting them in different objects. Weird … whether it’s a bug or a feature may be a semantic question.

7

These two code snippets are essentially equivalent:

gameMain: GameMainDef {
  myList: ShuffledList {
    ...
  }
}
anonListObj1: ShuffledList {
  ...
}

gameMain: GameMainDef {
  myList = anonListObj1
}

The “myBool = true” statement in showIntro() is setting self.myBool, but its self is different from the ShuffledList’s self, since they are distinct objects.

“myList.myBool = true” will set the property in the list object instead.