Hi Sean,





Thanks for your response. I didn't spot that Mason had a bag 

implementation. From reading the comments in the code it seems to be 

significantly faster than arrayLists.



Thanks



-Mike



Sean Luke wrote:

> Hi Michael.  MASON doesn't have these built-in, but the following  

> should do the trick.  This is a place where Bag significantly  

> outperforms ArrayList.  Note that if you're using ParallelSequence or  

> AsynchronousSteppable, you don't want to add objects to the list from  

> within those threads as it'd create a race condition that's not  checked 

> for in the code below.

> 

> Sean

> 

> public class ExpandableSequence implements Steppable

>     {

>     public Bag steps;

> 

>     public ExpandableSequence(Bag steps) { this.steps = steps; }

>     public ExpandableSequence() { this.steps = new Bag(); }

>     public ExpandableSequence(Steppable[] steps) { this.steps = new Bag 

> (steps); }

>     public void step(SimState state)

>         {

>         for(int x=0;x<steps.numObjs; x++)

>             ((Steppable)(steps.objs[x])).step(state);

>         }

>     }

> 

> 

> public class RandomExpandableSequence extends ExpandableSequence

>     {

>     public RandomExpandableSequence(Bag steps) { super(steps); }

>     public RandomExpandableSequence() { super(); }

>     public RandomExpandableSequence(Steppable[] steps) { super(steps); }

> 

>     public void step(SimState state)

>         {

>         synchronized(state.random)

>             { steps.shuffle(state.random); }

>         super.step(state);

>         }

>     }

> 

> 

> On Apr 4, 2006, at 11:04 AM, Michael Lees wrote:

> 

>> Hi,

>>

>> This is my first post to the list, I've been using mason for a few  

>> weeks now.

>>

>> I'm using the Sequence class but have found the steps array  

>> inflexible in terms of adding new Steppables during execution.

>>

>> I've implemented an ExpandableSequence which uses an arrayList  rather 

>> than an array. I was wondering if something already exists  for this? 

>> I might use RandomSequence at some point, which would  mean 

>> re-implementing RandomSequence to extend ExpandableSequence.





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