One more thing, perhaps you already implemented this but in this code;
----------------------------

Shred foo;

spork ~ test() @=> foo;

second => now;

<<<foo.id()>>>;

foo.exit();

second => now;

<<<foo.id()>>>;


fun void test()
    {
    while(1) second => now;
    }
----------------------------

I'd like the second call for foo.id to return 0. This is useful if test() is a function that performs a specific task, then exits and we'd like to know if it already did so. IMHO (but perhaps others have better suggestions) this would be cleaner then defining a extra variable for this (especially as we may not know how many we need) and if 0 is the id for non-existant shreds this would also save making a .ifExists() (or similar) call.

Perhaps there are unforeseen downsides to this?