Gets or sets the Atom at the specified index. In C# this
property is the indexer for the class.
You can access an Atom directly or you can use one of the
overloaded operators to specify numbers or strings. Using the
overloads to access numbers or strings is more efficient than
accessing an Atom and extracting the value from it.
You specify one of the overloads using the def parameter. If you
are setting a value then this parameter is ignored. If you are
getting a value then this parameter becomes the default value to be
used if the underlying Atom was not the correct type. For example
the default would be returned if you attempted to get an integer
but the underlying Atom was actually a StringAtom.
Atoms can exist in only one place at a time. If the Atom
supplied is already contained by another object then a Clone of the Atom is
Adding a null value will result in a NullAtom being added to the
If the index is not a valid index this property throws an