lastIsLabel removes labels from source array

[elgiano]

a = 1!2!3;
a.collect(_.size); 
// -> [2,2,2]
KDTree(a,lastIsLabel:true);
a.collect(_.size); 
// -> [1,1,1]

In KDTree.sc:init() sorted = array.copy; is a shallow copy (the array is copied, but each point's coordinates, which are array themselves, gets referenced instead), so if(lastIsLabel, { label = location.pop }); pops from the original list.

I understand that we don't want to copy at every recursion of the init process, so a solution is to deep copy the original array when creating the tree. Maybe it should be said in the docs?

a = 1!2!3;
a.collect(_.size); 
// -> [2,2,2]
KDTree(a.collect(_.copy),lastIsLabel:true);
a.collect(_.size); 
// -> [2,2,2]