There was some time since I used Chuck now, so I may be wrong on this one. But I get the feeling that you're not initializing l, right? On 10/06/07, eduard aylon wrote:

Hi list,

I am trying to make a list of objects where each object has references to other objects, but I am not succeeding and I get a NullPointerException. The piece of code below may represent what I am trying to do.

class object { Std.rand2f(0., 1.) => float f_; }

class Item extends object { 2 => int size_; object item_[size_];

fun void print() { for( 0=>int i; i>>; } <<<"----------------------------------------------">>>; <<<"calling print from within class definition">>>; <<<"----------------------------------------------">>>; print(); }

4 => int n; Item l[n];

// no problems up until here

<<<"----------------------------------------------">>>; <<<"calling print from outside class definition">>>; <<<"----------------------------------------------">>>;

for( 0=>int i; i

After execution I get: [chuck](VM): NullPointerException: shred[id=1:test.ck], PC=[37]

Excuse me if it's too obvious, but I can't see why it rises the null pointer exception. Any ideas?

thanks in advance,

eduard

_______________________________________________ chuck-users mailing list chuck-users@lists.cs.princeton.edu https://lists.cs.princeton.edu/mailman/listinfo/chuck-users

-- Love. /Bruce Harris -- -----BEGIN 2ROT13 MESSAGE----- Low Bitrate Netlabel: http://f-label.tojt.net/ Blog: http://gameboygenius.8bitcollective.com/ Sätt på ett par flipflops, vippa på rumpan och gör det här till en minnesvärd sommar! -----END 2ROT13 MESSAGE-----

Dear all, Sorry for the delay (currently in Beijing) - just got a chance to check this and was able to reproduce the exception. It indeed looks like a ChucK bug - will definitely look into this for the next release. By the way, there will be a big development round this summer (concurrent with some thesis fabrication) - we have a lot of new stuff on the move! Stay tuned. Best, Ge! On Jun 9, 2007, at 7:36 PM, eduard aylon wrote:

Hi list,

I am trying to make a list of objects where each object has references to other objects, but I am not succeeding and I get a NullPointerException. The piece of code below may represent what I am trying to do.

class object { Std.rand2f(0., 1.) => float f_; }

class Item extends object { 2 => int size_; object item_[size_];

fun void print() { for( 0=>int i; i>>; } <<<"----------------------------------------------">>>; <<<"calling print from within class definition">>>; <<<"----------------------------------------------">>>; print(); }

4 => int n; Item l[n];

// no problems up until here

<<<"----------------------------------------------">>>; <<<"calling print from outside class definition">>>; <<<"----------------------------------------------">>>;

for( 0=>int i; i

After execution I get: [chuck](VM): NullPointerException: shred[id=1:test.ck], PC=[37]

Excuse me if it's too obvious, but I can't see why it rises the null pointer exception. Any ideas?

thanks in advance,

eduard

_______________________________________________ chuck-users mailing list chuck-users@lists.cs.princeton.edu https://lists.cs.princeton.edu/mailman/listinfo/chuck-users

On 6/10/07, eduard aylon wrote:

Hi list,

I am trying to make a list of objects where each object has references to other objects, but I am not succeeding and I get a NullPointerException. The piece of code below may represent what I am trying to do.

One more reply to this, it might be obvious by now but I needed a workaround myself and was happy to find one, if a ugly one. Here's a edited version of the original demonstration code that gets around the bug. clearly this isn't going to work if the length of the array isn't defined in the code but is instead determined by the outcome of some opperation. Right now I don't think it's possible to have ChucK generate names for class instances as ChucK can't generate ChucK code, then run it. Somebody kindly corect me if I overlooked something in that regard. This would get quite anoying if -say- 50 "Items" were needed but if a dozen or so would do this might get people by untill this is fixed in a future version. Yours, kas. ========================== class object { Std.rand2f(0., 1.) => float f_; } class Item extends object { 2 => int size_; object item_[size_]; fun void print() { for( 0=>int i; i>>; } <<<"----------------------------------------------">>>; <<<"calling print from within class definition">>>; <<<"----------------------------------------------">>>; print(); } //4 => int n; (edited out by Kassen) // ugly and less versatile workaround starts here //this forces initiation to happen outside of the array Item a; Item b; Item c; Item d; //now we asign these to the array [a,b,c,d] @=> Item l[]; //end of workaround // no problems up until here <<<"----------------------------------------------">>>; <<<"calling print from outside class definition">>>; <<<"----------------------------------------------">>>; //notice I had to replace "n" by "l.cap()" here //this is functionally equivalent anyway for( 0=>int i; i