Collections of the type java.util.List, and all the list in xl.lang. : BooleanList, IntList, … ObjectList, have the operator shl overloaded.

• List << Object add the object to the list
• List << primitive add the primitive to the list

e.g. :

de.grogra.xl.util.ObjectList list = new ObjectList();
list << new Sphere() << new Box(); // add a sphere and a box objects to the objectlist
 
java.util.List list2 = new ArrayList();
list2 << 5 << 2 <<1; // add 5, 2, and 1 to the list.

• Object in Collection return true if the collection contains the object

println( new Sphere() in list) ; // false the new Sphere is not the same a the previous new Sphere();
println( 5 in list2) ; // true

• xl.util.XXList[index] get the index-th element of that list. XXList are list defined in xl.util package: IntList, BooleanList, …

de.grogra.xl.util.IntList l = new IntList();
l << 1 << 5 << 3 << 1 << 54;
println( l[3]); // print "3", the index starts at 0;